METHOD AND SYSTEM FOR CREATION AND USE OF A PHOTO ALBUM

Abstract: A method including providing a user with a photo album form printed on a surface, the photo album form containing information relating to a photo album activity and including coded data indicative of an identity of the photo album form and of a plurality of points on the form; receiving, in a computer system, data from a sensing device operated by the user, the data indicating the identity of the photo album form and a position of the sensing device relative to the photo album form; and identifying, in the computer system and from the indicating data, at least one parameter relating to the photo album activity; the method enabling the user to compose and print pages of photos suitable for inclusion in a photo album.

Description: METHOD AND SYSTEM FOR CREATION AND USE OF A PHOTO ALBUM FIELD OF INVENTION The present invention relates generally to distributed computing systems It concerns photo albums and, more particularly, is directed to a method and system for enabling the creation and use of a photo album CO-PENDING APPLICATIONS Various methods, systems and apparatus relating to the present invention are disclosed in the following co-pending applications filed by the applicant or assignee of the present invention simultaneously with the present application PCT/AU00/00518, PCT/AU00/00519, PCT/AU00/00520, PCT/AU00/00521 , PCT/AU00/00523, PCT/AU00/00524, PCT/AU00/00525, PCT/AU00/00526, PCT/AUOO/00527, PCT/AU00/00528, PCT/AU00/00529, PCT/AU00/00530, PCT/AUOO/00531, PCT/AU00/00532, PCT/AU00/00533, PCT/AUOO/00534, PCT/AU00/00535, PCT/AUOO/00536, PCT/AUOO/00537, PCT/AU00/00538, PCT/AUOO/00539, PCT/AU00/00540, PCT/AU00/00541 , PCT/AU00/00542, PCT/AU00/00543, PCT/AU00/00544. PCT/AU00/00545, PCT/AU00/00547, PCT/AU00/00546, PCT/AU00/00554, PCT/AUOO/00556, PCT/AU00/00557, PCT/AUOO/00558, PCT/AUOO/00559, PCT/AU00/00560, PCT/AU00/00561 , PCT/AU00/00562, PCT/AU00/00563, PCT/AU00/00564, PCT/AU00/00566, PCT/AU00/00567, PCT/AU00/00568, PCT/AUOO/00569, PCT/AU00/00570, PCT/AUOO/00571, PCT/AU00/00572, PCT/AU00/00573, PCT/AU00/00574, PCT/AU00/00575, PCT/AU00/00576, PCT/AU00/00577, PCT/AU00/00578, PCT/AU00/00579, PCT/AUOO/00581 , PCT/AU00/00580, PCT/AUOO/00582, PCT/AU00/00587, PCT/AUOO/00588, PCT/AUOO/00589, PCT/AU00/00583, PCT/AU00/00593 PCT/AU00/00590, PCT/AU00/00591 , PCT/AU00/00592, PCT/AU00/00594, PCT/AU00/00595. PCT/AU00/00596, PCT/AUOO/00597, PCT/AU00/00598, PCT/AU00/00516, and PCT/AU00/00517 The disclosures of these co-pending applications are incorporated herein by cross-reference BACKGROUND The use of digital cameras and the organization of the resulting digital photographic images is already well established Similarly, the scanning of optical images and the storage and organization of the resulting digital versions is also well known Commonly available computer programs allow stored images to be displayed on a screen and resized/edited/rearranged before the user finally prints out a hard copy SUMMARY OF INVENTION It is an objective of the present invention to provide a new system and method for enabling the creation and use of a photo album The present invention provides, in one aspect, a method of enabling the creation and use of a photo album the method including the steps of providing a photo album user with at least one photo album form printed on a surface, the photo album form containing information relating to a photo album activity and including coded data indicative of an identity of the photo album form and of at least one reference point of the photo album form, Rectified sheet - 1a - receiving, in a computer system, indicating data from a sensing device operated by said user, said indicating data regarding the identity of the photo album form and a position of the sensing device relative to the photo album form, the sensing device, when placed in an operative position relative to the photo album form, sensing the indicating data using at least some of the coded data, and identifying in the computer system and from the indicating data, at least one parameter relating to the photo album activity In a further aspect, the invention provides a method of enabling the creation and use of a photo album, the method including the steps of providing a user with at least one photo album form printed on a surface, the photo album form containing information relating to a photo album activity and including coded data indicative of at least one parameter of the photo album activity, Rectified sheet - 2 - receivmg, m a computer system, data from a sensmg device operated by said user regarding said at least one parameter and regarding movement of the sensmg device relative to the photo album form, the sensmg device, when moved relative to the photo album form, sensmg the data regarding said at least one parameter usmg at least some of the coded data and generating the data regarding its own movement relative to the photo album form, and interpreting, in the computer system, said movement of the sensmg device as it relates to said at least one parameter In yet a further aspect, the invention provides a system for enablmg the creation and use of a photo album, the system including at least one photo album form printed on a surface, the photo album form containing information relating to a photo album activity and including coded data indicative of an identity of the photo album form and of at least one reference pomt of the photo album form, and a computer system for receiving mdicatmg data from a sensmg device operated by a user involved m the photo album activity, said mdicatmg data regardmg the identity of the photo album form and a position of the sensmg device relative to the photo album form, the sensmg device, when placed m an operative position relative to the photo album form, sensmg the mdicatmg data usmg at least some of the coded data, said computer system including means for identifying, from the mdicatmg data, at least one parameter relating to the photo album activity In still another aspect, the invention provides a system for enablmg the creation and use of a photo album, the system including at least one photo album form printed on a surface, the photo album form containing information relating to a photo album activity and including coded data indicative of at least one parameter of the photo album activity, and a computer system for receiving data from a sensmg device operated by the user mvolved m the photo album activity, said data regardmg movement of the sensmg device relative to the photo album form, and for interpreting said movement of the sensmg device as it relates to said at least one parameter, the sensmg device, when moved relative to the photo album form, sensmg the data regardmg said at least one parameter usmg at least some of the coded data, and generating the data regarding its own movement relative to the photo album form Accordingly, the present invention provides a system and a methc which utilizes one or more forms capable of interacting with a computer system Whilst the novel method and system of the present invention may be used m conjunction with a smgle computer system, m a particularly preferred form it is designed to operate over a computer network, such as the Internet Physically, the form is disposed on a surface medium of any suitable structure However, m a preferred arrangement, the form is disposed on sheet material such as paper or the like which has the coded data printed on it and which allows interaction with the computer system The coded data is detectable preferably, but not exclusively, outside the visible spectrum, thereby enablmg it to be machine-readable but substantially invisible to the human eye The form may also include visible material which provides information to a user, such as the application or purpose of the form, and which visible information may be registered or correlate m position with the relevant hidden coded data The system also mcludes a sensmg device to convey data from the form to the computer system, and in some instances, to contribute additional data Again, the sensmg device may take a variety of forms but is preferably compact and easily portable In a particularly preferred arrangement, the sensmg device is configured as a pen which is designed to be able to physically mark the form as well as to selectively enable the coded data from the form to be read and transmitted to the computer system The coded data then provides control information, configured such that designation thereof by a user causes instructions to be applied to the software running on the computer system or network - 3 - The nature of the interaction between the form and the sensmg device and the data that each contributes to the computer system may vary In one arrangement, the coded data on the form is mdicative of the identity of the form and of at least one reference point on that form In another embodiment, the form includes coded data which is mdicative of a parameter of the form, whereas the sensmg device is operative to provide data regarding its own movement relative to that form to the computer system together with coded data from the form In yet another arrangement, the form mcludes the coded data which at least identifies the form, and the sensmg device is designed to provide, to the computer system, data based on the form coded data, and also on data which identifies the user of the device In a preferred arrangement, the system and method also employs specially designed printers to print the form Further these printers constitute or form part of the computer system and are designed to receive data from the sensmg device As indicated above, the system and method of the invention is ideally suited to operate over a network In this arrangement, the printers are fully integrated mto the network and allow for printing of the forms on demand and also for distributing of the forms usmg a mixture of multicast and pomtcast communication protocols Accordingly, m a preferred form, the present mvention provides methods and systems which use a paper and pen based interface for a computer system This provides many significant benefits over traditional computer systems The advantage of paper is that it is widely used to display and record information Further, printed information is easier to read than information displayed on a computer screen Moreover, paper does not run on batteries, can be read m bright light, or robustly accepts coffee spills or the like and is portable and disposable Furthermore, the system allows for hand-drawing and handwriting to be captured which affords greater richness of expression than mput via a computer keyboard and mouse The present mvention therefore provides a novel system and method for enablmg the creation and use of a photo album making use of novel interactive surface media The term 'photo' or 'photograph' refers to a digital version of a user's stored photographic image, but also refers to the image once it has been printed, for example onto a hard copy of a page of a user's photo album A user of the novel interactive media system automatically collects photos on the associated computer system via a special digital camera, or can explicitly squirt photos from a conventional digital camera to the associated computer system via an appropπate interface device The system then enables the user to organize their photograph collection and to print then photos as desired BRIEF DESCRIPTION OF DRAWINGS Preferred and other embodiments of the mvention will now be described, by way of non-limiting example only, with reference to the accompanying drawings, m which Figure 1 is a schematic of a the relationship between a sample printed netpage and its online page description, Figure 2 is a schematic view of a interaction between a netpage pen, a netpage printer, a netpage page server, and a netpage application server, Figure 3 illustrates a collection of netpage servers and printers interconnected via a network, Figure 4 is a schematic view of a high-level structure of a printed netpage and its online page description, Figure 5 is a plan view showing a structure of a netpage tag, Figure 6 is a plan view showing a relationship between a set of the tags shown m Figure 5 and a field of view of a netpage sensmg device m the for of a netpage pen Figure 7 is a flowchart of a tag image processmg and decoding algorithm, Figure 8 is a perspective view of a netpage pen and its associated tag-sensing field-of-view cone, Figure 9 is a perspective exploded view of the netpage pen shown m Figure 8, - 4 - Figure 10 is a schematic block diagram of a pen controller for the netpage pen shown m Figures 8 and 9, Figure 11 is a perspective view of a wall-mounted netpage prmter, Figure 12 is a section through the length of the netpage prmter of Figure 11 , Figure 12a is an enlarged portion of Figure 12 showing a section of the duplexed prmt engmes and glue wheel assembly, Figure 13 is a detailed view of the mk cartπdge, ink, air and glue paths, and prmt engmes of the netpage prmter of Figures 11 and 12, Figure 14 is a schematic block diagram of a prmter controller for the netpage prmter shown m Figures 11 and 12, Figure 15 is a schematic block diagram of duplexed prmt engme controllers and Mem et™ prmtheads associated with the prmter controller shown m Figure 14, Figure 16 is a schematic block diagram of the prmt engme controller shown m Figures 14 and 15, Figure 17 is a perspective view of a smgle Memjet™ printing element, as used in, for example, the netpage prmter of Figures 10 to 12, Figure 18 is a perspective view of a small part of an array of Memjet™ printing elements, Figure 19 is a seπes of perspective views illustrating the operating cycle of the Memjet™ printing element shown in Figure 13, Figure 20 is a perspective view of a short segment of a pagewidth Memjet™ pπnthead, Figure 21 is a schematic view of a user class diagram, Figure 22 is a schematic view of a prmter class diagram, Figure 23 is a schematic view of a pen class diagram, Figure 24 is a schematic view of an application class diagram, Figure 25 is a schematic view of a document and page descπption class diagram, Figure 26 is a schematic view of a document and page ownership class diagram, Figure 27 is a schematic view of a terminal element specialization class diagram, Figure 28 is a schematic view of a static element specialization class diagram, Figure 29 is a schematic view of a hyperlink element class diagram, Figure 30 is a schematic view of a hyperlink element specialization class diagram, Figure 31 is a schematic view of a hyperlmked group class diagram, Figure 32 is a schematic view of a form class diagram, Figure 33 is a schematic view of a digital ink class diagram, Figure 34 is a schematic view of a field element specialization class diagram, Figure 35 is a schematic view of a checkbox field class diagram, Figure 36 is a schematic view of a text field class diagram, Figure 37 is a schematic view of a signature field class diagram, Figure 38 is a flowchart of an mput processmg algoπthm, Figure 38a is a detailed flowchart of one step of the flowchart of Figure 38, Figure 39 is a schematic view of a page server command element class diagram, Figure 40 is a schematic view of a resource descπption class diagram, Figure 41 is a schematic view of a favontes list class diagram, Figure 42 is a schematic view of a history list class diagram, Figure 43 is a schematic view of a subscπption delivery protocol, Figure 44 is a schematic view of a hyperlink request class diagram, Figure 45 is a schematic view of a hyperlink activation protocol, - 5 - Figure 46 is a schematic view of a form submission protocol, Figure 47 is a schematic view of a commission payment protocol, Figure 48 is a schematic view of a set of user interface flow document icons, Figure 49 is a schematic view of a set of user interface page layout element icons, Figure 50 is a schematic view of a photo collection class diagram, Figure 51 is a schematic view of a photo class diagram, Figure 52 is a schematic view of a photo squirting user interface flow, Figure 53 is a schematic view of a photo browsmg user interface flow, Figure 54 is a schematic view of a photo printing user interface flow, Figure 55 is a schematic view of an add squirted photos form, Figure 56 is a schematic view of a photo manager menu form, Figure 57 is a schematic view of a photo history list form, Figure 58 is a schematic view of a photo list form, Figure 5 is a schematic view of a photo folder list form, Figure 60 is a schematic view of a copy/move to photo folder form, Figure 61 is a schematic view of a photo folder form, Figure 62 is a schematic view of a photo thumbnails page, Figure 63 is a schematic view of a custom photo prmt form, Figure 64 is a schematic view of a photo album class diagram, Figure 65 is a schematic view of a photo option class diagram, Figure 66 is a schematic view of available graphic photo options, Figure 67 is a schematic view of a photo album browsmg user interface flow, Figure 68 is a schematic view of an album page composition user interface flow, Figure 69 is a schematic view of a photo album list form, Figure 70 is a schematic view of a photo album form, Figure 71 is a schematic view of a copy/move page to photo album form, Figure 72 is a schematic view of an album page composition form, Figure 73 is a schematic view of an edit photo form, and Figure 74 is a schematic view of a photo album page DETAILED DESCRIPTION OF PREFERRED AND OTHER EMBODIMENTS Note Memjet™ is a trade mark of Silverbrook Research Pty Ltd, Australia In the preferred embodiment, the mvention is configured to work with the netpage networked computer system, a detailed overview of which follows It will be appreciated that not every implementation will necessaπly embody all or even most of the specific details and extensions discussed below m relation to the basic system However, the system is descπbed m its most complete form to reduce the need for external reference when attempting to understand the context m which the preferred embodiments and aspects of the present mvention operate In bπef summary, the prefeπed form of the netpage system employs a computer mterface m the form of a mapped surface, that is, a physical surface which contams references to a map of the surface mamtamed m a computer system The map references can be queπed by an appropnate sensmg device Depending upon the specific implementation, the map references may be encoded visibly or invisibly, and defined m such a way that a local query on the mapped surface yields an unambiguous map reference both within the map and among different maps The computer system can contain information about features on the mapped surface, and such information can be retneved based on - 6 - map references supplied by a sensmg device used with the mapped surface The information thus retπeved can take the form of actions which are mitiated by the computer system on behalf of the operator m response to the operator's interaction with the surface features In its preferred form, the netpage system relies on the production of, and human interaction with, netpages These are pages of text, graphics and images printed on ordinary paper, but which work like interactive web pages Information is encoded on each page usmg mk which is substantially invisible to the unaided human eye The mk, however, and thereby the coded data, can be sensed by an optically imagmg pen and transmitted to the netpage system In the preferred form, active buttons and hyperlinks on each page can be clicked with the pen to request information from the network or to signal preferences to a network server In one embodiment, text wπtten by hand on a netpage is automatically recognized and converted to computer text m the netpage system, allowing forms to be filled m In other embodiments, signatures recorded on a netpage are automatically veπfied, allowing e-commerce transactions to be securely authorized As illustrated m Figure 1, a printed netpage 1 can represent a interactive form which can be filled m by the user both physically, on the printed page, and "electronically", via communication between the pen and the netpage system The example shows a "Request" form containing name and address fields and a submit button The netpage consists of graphic data 2 printed usmg visible ink, and coded data 3 printed as a collection of tags 4 usmg invisible ink The corresponding page descπption 5, stored on the netpage network, descnbes the individual elements of the netpage In particular it descnbes the type and spatial extent (zone) of each interactive element (I e text field or button m the example), to allow the netpage system to correctly interpret mput via the netpage The submit button 6, for example, has a zone 7 which coπesponds to the spatial extent of the corresponding graphic 8 As illustrated m Figure 2, the netpage pen 101, a preferred form of which is shown m Figures 8 and 9 and descπbed m more detail below, works m conjunction with a netpage printer 601, an Internet-connected printing appliance for home, office or mobile use The pen is wireless and communicates securely with the netpage prmter via a short-range radio link 9 The netpage prmter 601, a preferred form of which is shown in Figure 11 to 13 and descπbed m more detail below, is able to deliver, peπodically or on demand, personalized newspape ,, magazines, catalogs, brochures and other publications, all printed at high quality as interactive netpages Unlike a personal computer, the netpage prmter is an appliance which can be, for example, wall-mounted adjacent to an area where the morning news is first consumed, such as m a user's kitchen, near a breakfast table, or near the household's pomt of departure for the day It also comes m tabletop, desktop, portable and miniature versions Netpages printed at then- pomt of consumption combme the ease-of-use of paper with the timeliness and interactivity of an interactive medium As shown m Figure 2, the netpage pen 101 interacts with the coded data on a printed netpage 1 and communicates, via a short-range radio link 9, the interaction to a netpage prmter The prmter 601 sends the interaction to the relevant netpage page server 10 for interpretation In appropπate circumstances, the page server sends a corresponding message to application computer software running on a netpage application server 13 The application server may m turn send a response which is printed on the onginating prmter The netpage system is made considerably more convenient in the preferred embodiment by bemg used m conjunction with high-speed microelectromechamcal system (MEMS) based Inkjet (Memjet™) printers In the preferred form of this technology, relatively high-speed and high-quality printing is made more affordable to consumers In its prefeπed form, a netpage publication has the physical characteπstics of a traditional newsmagazine, such as a set of letter-size glossy pages printed m full color on both sides, bound together for easy navigation and comfortable handling - 7 - The netpage prmter exploits the growing availability of broadband Internet access Cable service is available to 95% of households m the Umted States, and cable modem service offering broadband Internet access is already available to 20% of these The netpage prmter can also operate with slower connections, but with longer delivery times and lower image quality Indeed, the netpage system can be enabled usmg existing consumer Inkjet and laser prmters, although the system will operate more slowly and will therefore be less acceptable from a consumer's pomt of view In other embodiments, the netpage system is hosted on a pπvate intranet In still other embodiments, the netpage system is hosted on a smgle computer or computer-enabled device, such as a printer Netpage publication servers 14 on the netpage network are configured to deliver pπnt-qualtty publications to netpage prmters Peπodical publications are delivered automatically to subscribing netpage printers via pomtcasting and multicasting Internet protocols Personalized publications are filtered and formatted according to individual user profiles A netpage prmter can be configured to support any number of pens, and a pen can work with any number of netpage prmters In the preferred implementation, each netpage pen has a unique identifier A household may have a collection of colored netpage pens, one assigned to each member of the family This allows each user to maintain a distinct profile with respect to a netpage publication server or application server A netpage pen can also be registered with a netpage registration server 11 and linked to one or more payment card accounts This allows e-commerce payments to be securely authorized usmg the netpage pen The netpage registration server compares the signature captured by the netpage pen with a previously registered signature, allowing it to authenticate the user's identity to an e-commerce server Other biometπcs can also be used to veπfy identity A version of the netpage pen mcludes fingerprint scanning, veπfied m a similar way by the netpage registration server Although a netpage prmter may deliver peπodicals such as the morning newspaper without user intervention, it can be configured never to deliver unsolicited junk mail In its preferred form, it only delivers peπodicals from subscnbed or otherwise authorized sources In this respect, the netpage prmter is unlike a fax machine or e-mail account which is visible to any junk mailer who knows the telephone number or email address 1 NETPAGE SYSTEM ARCHITECTURE Each object model m the system is descπbed usmg a Unified Modelmg Language (UML) class diagram A class diagram consists of a set of object classes connected by relationships, and two lands of relationships are of mterest here associations and generalizations An association represents some land of relationship between objects, I e between instances of classes A generalization relates actual classes, and can be understood m the following way if a class is thought of as the set of all objects of that class, and class A is a generalization of class B, then B is simply a subset of A The UML does not directly support second-order modelling - 1 e classes of classes Each class is drawn as a rectangle labelled with the name of the class It contams a list of the attπbutes of the class, separated from the name by a horizontal lme, and a list of the operations of the class, separated from the attπbute list by a horizontal lme In the class diagrams which follow, however, operations are never modelled An association is drawn as a lme joining two classes, optionally labelled at either end with the multiplicity of the association The default multiplicity is one An asteπsk (*) indicates a multiplicity of "many", 1 e zero or more Each association is optionally labelled with its name, and is also optionally labelled at either end with the role of the corresponding class An open diamond indicates an aggregation association ("ls-part-of '), and is drawn at the aggregator end of the association lme A generalization relationship ("ts-a") is drawn as a solid lme joining two classes, with an arrow (m the form of an open tπangle) at the generalization end When a class diagram is broken up mto multiple diagrams, any class which is duplicated is shown with a - 8 - dashed outline m all but the mam diagram which defines it It is shown with attributes only where it is defined 1.1 NETPAGES Netpages are the foundation on which a netpage network is built They provide a paper-based user interface to published information and interactive services A netpage consists of a printed page (or other surface region) invisibly tagged with references to an onlme descπption of the page The onlme page descπption is mamtamed persistently by a netpage page server The page descπption descnbes the visible layout and content of the page, mcludmg text, graphics and images It also descnbes the mput elements on the page, mcludmg buttons, hyperlinks, and mput fields A netpage allows markmgs made with a netpage pen on its surface to be simultaneously captured and processed by the netpage system Multiple netpages can share the same page descπption However, to allow mput through otherwise identical pages to be distinguished, each netpage is assigned a unique page identifier This page ID has sufficient precision to distinguish between a very large number of netpages Each reference to the page descπption is encoded m a printed tag The tag identifies the unique page on which it appears, and thereby indirectly identifies the page descπption The tag also identifies its own position on the page Charactenstics of the tags are descπbed m more detail below Tags are printed m infrared-absorptive mk on any substrate which is infrared-reflective, such as ordinary paper Near-infrared wavelengths are invisible to the human eye but are easily sensed by a solid-state image sensor with an appropπate filter A tag is sensed by an area image sensor m the netpage pen, and the tag data is transmitted to the netpage system via the nearest netpage prmter The pen is wireless and communicates with the netpage prmter via a short-range radio link Tags are sufficiently small and densely arranged that the pen can reliably image at least one tag even on a smgle click on the page It is important that the pen recognize the page ID and position on every interaction with the page, smce the interaction is stateless Tags are error-correctably encoded to make them partially tolerant to surface damage The netpage page server maintains a unique page instance for each printed netpage, allowing it to maintain a distinct set of user-supplied values for mput fields m the page descπption for each printed netpage The relationship between the page descπption, the page instance, and the printed netpage is shown m Figure 4 The page instance is associated with both the netpage printer which printed it and, if known, the netpage user who requested it 1.2 NETPAGE TAGS 1.2.1 Tag Data Content In a preferred form, each tag identifies the region m which it appears, and the location of that tag within the region A tag may also contain flags which relate to the region as a whole or to the tag One or more flag bits may, for example, signal a tag sensmg device to provide feedback mdicative of a function associated with the immediate area of the tag, without the sensmg device having to refer to a descnption of the region A netpage pen may, for example, illuminate an "active area" LED when m the zone of a hyperlink As will be more clearly explained below, m a preferred embodiment, each tag contams an easily recognized mvaπant structure which aids initial detection, and which assists m muu izmg the effect of any warp induced * by the surface or by the sensmg process The tags preferably tile the entire page, and are sufficiently small and densely arranged that the pen can reliably image at least one tag even on a smgle click on the page It is important that the pen recognize the page ID and position on every interaction with the page, smce the interaction is stateless In a preferred embodiment, the region to which a tag refers coincides with an entire page, and the region ID encoded m the tag is therefore synonymous with the page ID of the page on which the tag appears In other - 9 - embodiments, the region to which a tag refers can be an arbitrary subregion of a page or other surface For example, it can comcide with the zone of an mteractive element, m which case the region ID can directly identify the mteractive element Table 1 - Tag data Each tag contams 120 bits of formation, typically allocated as shown m Table 1 Assuming a maximum tag density of 64 per square mch, a 16-bit tag ID supports a region size of up to 1024 square mches Larger regions can be mapped continuously without increasing the tag ID precision simply by usmg abutting regions and maps The 100-bit region ID allows 2 100 (~10 30 or a million tnllion trillion) different regions to be uniquely identified 1.2.2 Tag Data Encoding The 120 bits of tag data are redundantly encoded usmg a (15, 5) Reed-Solomon code This yields 360 encoded bits consisting of 6 codewords of 15 4-bit symbols each The (15, 5) code allows up to 5 symbol errors to be corrected per codeword, 1 e it is tolerant of a symbol error rate of up to 33% per codeword Each 4-bit symbol is represented m a spatially coherent way m the tag, and the symbols of the six codewords are mterleaved spatially within the tag This ensures that a burst error (an eπor affecting multiple spatially adjacent bits) damages a minimum number of symbols overall and a minimum number of symbols m any one codeword, thus maximising the likelihood that the burst error can be fully corrected 1.2.3 Physical Tag Structure The physical representation of the tag, shown m Figure 5, mcludes fixed target structures 15, 16, 17 and vanable data areas 18 The fixed target structures allow a sensmg device such as the netpage pen to detect the tag and infer its three-dimensional oπentation relative to the sensor The data areas contain representations of the individual bits of the encoded tag data To achieve proper tag reproduction, the tag is rendered at a resolution of 256x256 dots When printed at 1600 dots per mch this yields a tag with a diameter of about 4 mm At this resolution the tag is designed to be surrounded by a "quiet area" of radius 16 dots Smce the quiet area is also contnbuted by adjacent tags, it only adds 16 dots to the effective diameter of the tag The tag mcludes six target structures A detection ring 15 allows the sensmg device to initially detect the tag The πng is easy to detect because it is rotationally mvanant and because a simple correction of its aspect ratio removes most of the effects of perspective distortion An oπentation axis 16 allows the sensmg device to determine the approximate planar onentation of the tag due to the yaw of the sensor The onentation axis is skewed to yield a unique onentation Four perspective targets 17 allow the sensmg device to infer an accurate two-dimensional perspective transform of the tag and hence an accurate three-dimensional position and oπentation of the tag relative to the sensor All target structures are redundantly large to improve their immunity to noise The overall tag shape is circular This supports, amongst other things, optimal tag packing on an irregular tπangular gnd In combination with the circular detection ring, this makes a circular arrangement of data bits within the tag optimal To maximise its size, each data bit is represented by a radial wedge m the form of an area bounded by two radial lines and two concentnc circular arcs Each wedge has a minimum dimension of 8 dots at 1600 dpi and is designed so that its base (its inner arc), is at least equal to this minimum dimension The height of the wedge m the radial direction is always equal to the minimum dimension Each 4-bit data symbol is represented by an array of 2x2 - 10 - wedges The 15 4-bit data symbols of each of the six codewords are allocated to the four concentπc symbol rings 18a to 18d in interleaved fashion Symbols are allocated alternately m circular progression around the tag The interleaving is designed to maximise the average spatial distance between any two symbols of the same codeword In order to support "single-click" interaction with a tagged region via a sensmg device, the sensmg device must be able to see at least one entire tag m its field of view no matter where m the region or at what oπentation it is positioned The reqmred diameter of the field of view of the sensmg device is therefore a function of the size and spacmg of the tags Assuming a circular tag shape, the minimum diameter of the sensor field of view is obtained when the tags are tiled on a equilateral tπangular gπd, as shown m Figure 6 1.2.4 Tag Image Processing and Decoding The tag image processing and decoding performed by a sensmg device such as the netpage pen is shown m Figure 7 While a captured image is bemg acquired from the image sensor, the dynamic range of the image is determined (at 20) The center of the range is then chosen as the binary threshold for the image 21 The image is then thresholded and segmented mto connected pixel regions (I e shapes 23) (at 22) Shapes which are too small to represent tag target structures are discarded The size and centroid of each shape is also computed Binary shape moments 25 are then computed (at 24) for each shape, and these provide the basis for subsequently locating target structures Central shape moments are by their nature mvanant of position, and can be easily made mvanant of scale, aspect ratio and rotation. The ring target structure 15 is the first to be located (at 26) A πng has the advantage of bemg very well behaved when perspective-distorted Matching proceeds by aspect-normalizing and rotation-normalizing each shape's moments Once its second-order moments are normalized the ring is easy to recognize even if the perspective distortion was significant The ring's ongmal aspect and rotation 27 together provide a useful approximation of the perspective transform The axis target structure 16 is the next to be located (at 28) Matc r proceeds by applying the ring's normalizations to each shape's moments, and rotation-normalizing the resulting moments Once its second-order moments are normalized the axis target is easily recognized Note that one third order moment is required to disambiguate the two possible oπentations of the axis The shape is deliberately skewed to one side to make this possible Note also that it is only possible to rotation-normalize the axis target after it has had the ring's normalizations applied, smce the perspective distortion can hide the axis target's axis The axis target's ongmal rotation provides a useful approximation of the tag's rotation due to pen yaw 29 The four perspective target structures 17 are the last to be located (at 30) Good estimates of then" positions are computed based on their known spatial relationships to the ring and axis targets, the aspect and rotation of the πng, and the rotation of the axis Matching proceeds by applying the ring's normalizations to each shape's moments Once then second-order moments are normalized the circular perspective targets are easy to recognize, and the target closest to each estimated position is taken as a match The ongmal centroids of the four perspective targets are then taken to be the perspective-distorted corners 31 of a square of known size m tag space, and an eight-degree-of-freedom perspective transform 33 is inferred (at 32) based on solvmg the well-understood equations relating the four tag-space and rmage- space pomt pairs The inferred tag-space to image-space perspective transform is used to project (at 36) each known data bit position m tag space mto image space where the real-valued position is used to bilmearly interpolate (at 36) the four - 11 - relevant adjacent pixels m the mput image The previously computed image threshold 21 is used to threshold the result to produce the final bit value 37 Once all 360 data bits 37 have been obtained m this way, each of the six 60-bit Reed-Solomon codewords is decoded (at 38) to yield 20 decoded bits 39, or 120 decoded bits m total Note that the codeword symbols are sampled in codeword order, so that codewords are implicitly de-mterleaved during the sampling process The πng target 15 is only sought in a subarea of the image whose relationship to the image guarantees that the πng, if found, is part of a complete tag If a complete tag is not found and successfully decoded, then no pen position is recorded for the current frame Given adequate processmg power and ideally a non-mmimal field of view 193, an alternative strategy mvolves seeking another tag m the current image The obtained tag data indicates the identity of the region containing the tag and the position of the tag within the region An accurate position 35 of the pen nib m the region, as well as the overall oπentation 35 of the pen, is then inferred (at 34) from the perspective transform 33 observed on the tag and the known spatial relationship between the pen's physical axis and the pen's optical axis 1.2.5 Tag Map Decoding a tag results in a region ID, a tag ID, and a tag-relative pen transform Before the tag ID and the tag-relative pen location can be translated mto an absolute location within the tagged region, the location of the tag within the region must be known This is given by a tag map, a function which maps each tag ID m a tagged region to a corresponding location The tag map class diagram is shown m Figure 22, as part of the netpage prmter class diagram A tag map reflects the scheme used to tile the surface region with tags, and this can vary according to surface type When multiple tagged regions share the same tiling scheme and the same tag numbering scheme, they can also share the same tag map The tag map for a region must be retπevable via the region ID Thus, given a region ID, a tag ID and a pen transform, the tag map can be retrieved, the tag ID can be translated mto an absolute tag location within the region, and the tag-relative pen location can be added to the tag location to yield an absolute pen location within the region 1.2.6 Tagging Schemes Two distinct surface coding schemes are of mterest, both of which use the tag structure descπbed earlier m this section The preferred coding scheme uses "location-indicating" tags as already discussed An alternative coding scheme uses object-indicating tags A location-indicating tag contams a tag ID which, when translated through the tag map associated with the tagged region, yields a unique tag location within the region The tag-relative location of the pen is added to this tag location to yield the location of the pen within the region This m turn is used to determine the location of the pen relative to a user interface element m the page descπption associated with the region Not only is the user interface element itself identified, but a location relative to the user mterface element is identified Location-indicating tags therefore tπvially support the capture of an absolute pen path m the zone of a particular user mterface element An object-indicating tag contams a tag ID which directly identifies a user mterface element m the page descπption associated with the region All the tags m the zone of the user mterface element identify the user mterface element, making them all identical and therefore indistinguishable Object-indicating tags do not, therefore, support the capture of an absolute pen path They do, however, support the capture of a relative pen path So long as the position sampling frequency exceeds twice the encountered tag frequency, the displacement from one sampled pen position to the next withm a stroke can be unambiguously determined With either tagging scheme, the tags function m cooperation with associated visual elements on the netpage as user mteractive elements m that a user can mteract with the printed page usmg an appropπate sensmg device m order for tag data to be read by the sensmg device and for an appropπate response to be generated m the netpage system - 12 - 1.3 DOCUMENT AND PAGE DESCRIPTIONS A preferred embodiment of a document and page descπption class diagram is shown m Figures 25 and 26 In the netpage system a document is descπbed at three levels At the most abstract level the document 836 has a hierarchical structure whose termmal elements 839 are associated with content objects 840 such as text objects, text style objects, image objects, etc Once the document is printed on a prmter with a particular page size and according to a particular user's scale factor preference, the document is pagmated and otherwise formatted Formatted termmal elements 835 will in some cases be associated with content objects which are different from those associated with their corresponding terminal elements, particularly where the content objects are style-related Each printed instance of a document and page is also descnbed separately, to allow mput captured through a particular page instance 830 to be recorded separately from mput captured through other instances of the same page descnption The presence of the most abstract document descnption on the page server allows a user to request a copy of a document without bemg forced to accept the source document's specific format The user may be requesting a copy through a prmter with a different page size, for example Conversely, the presence of the formatted document descπption on the page server allows the page server to efficiently interpret user actions on a particular printed page A formatted document 834 consists of a set of formatted page descπptions 5, each of which consists of a set of formatted terminal elements 835 Each formatted element has a spatial extent or zone 58 on the page This defines the active area of mput elements such as hyperlinks and mput fields A document instance 831 corresponds to a formatted document 834 It consists of a set of page instances 830, each of which corresponds to a page descnption 5 of the formatted document Each page instance 830 descnbes a smgle unique printed netpage 1, and records the page ID 50 of the netpage A page instance is not part of a document instance if it represents a copy of a page requested m isolation A page instance consists of a set of terminal element instances 832 An element instance only exists if it records instance-specific information Thus, a hyperlink instance exists for a hyperlink element because it records a transaction ID 55 which is specific to the page instance, and a field instance exists for a field element because it records mput specific to the page instance An element instance does not exist, however, for static elements such as textflows A termmal element can be a static element 843, a hyperlink element 844, a field element 845 or a page server command element 846, as shown m Figure 27 A static element 843 can be a style element 847 with an associated style object 854, a textflow element 848 with an associated styled text object 855, an image element 849 with an associated image element 856, a graphic element 850 with an associated graphic object 857, a video clip element 851 with an associated video clip object 858, an audio clip element 852 with an associated audio clip object 859, or a scπpt element 853 with an associated scnpt object 860, as shown m Figure 28 A page instance has a background field 833 which is used to record any digital ink captured on the page which does not apply to a specific mput element In the preferred form of the mvention, a tag map 811 is associated with each page instance to allow tags on the page to be translated mto locations on the page 1.4 THE NETPAGE NETWORK In a preferred embodiment, a netpage network consists of a distπbuted set of netpage page servers 10, netpage registration servers 11, netpage ID servers 12, netpage application servers 13, netpage publication servers 14, and netpage prmters 601 connected via a network 19 such as the Internet, as shown m Figure 3 The netpage registration server 11 is a server which records relationships between users, pens, prmters, applications and publications, and thereby authorizes vanous network activities It authenticates users and acts as a signing proxy on behalf of authenticated users m application transactions It also provides handwriting recognition services As descnbed above, a netpage page server 10 maintains persistent information about page descπptions and - 13 - page instances The netpage network mcludes any number of page servers, each handling a subset of page instances Smce a page server also mamtams user mput values for each page instance, clients such as netpage prmters send netpage mput directly to the appropπate page server The page server mterprets any such mput relative to the descnption of the corresponding page A netpage ID server 12 allocates document IDs 51 on demand, and provides load-balancing of page servers via its ID allocation scheme A netpage prmter uses the Internet Distributed Name System (DNS), or similar, to resolve a netpage page ID 50 mto the network address of the netpage page server handling the corresponding page instance A netpage application server 13 is a server which hosts mteractive netpage applications A netpage publication server 14 is an application server which publishes netpage documents to netpage prmters They are descπbed m detail m Section 2 Netpage servers can be hosted on a vanety of network server platforms from manufacturers such as IBM, Hewlett-Packard, and Sun Multiple netpage servers can run concurrently on a smgle host, and a smgle server can be distributed over a number of hosts Some or all of the functionality provided by netpage servers, and m particular the functionality provided by the ID server and the page server, can also be provided directly in a netpage appliance such as a netpage printer, m a computer workstation, or on a local network 1.5 THE NETPAGE PRINTER The netpage prmter 601 is an appliance which is registered with the netpage system and prints netpage documents on demand and via subscπption Each printer has a unique printer ID 62, and is connected to the netpage network via a network such as the Internet, ideally via a broadband connection Apart from identity and secunty settings m non-volatile memory, the netpage prmter contams no persistent storage As far as a user is concerned, "the network is the computer" Netpages function interactively across space and time with the help of the distnbuted netpage page servers 10, independently of particular netpage prmters The netpage prmter receives subscnbed netpage documents from netpage publication servers 14 Each document is distnbuted m two parts the page layouts, and the actual text and image objects which populate the pages Because of personalization, page layouts are typically specific to a particular subscπber and so are pomtcast to the subscπber's prmter via the appropnate page server Text and image objects, on the other hand, are typically shared with other subscπbers, and so are multicast to all subscnbers' prmters and the appropnate page servers The netpage publication server optimizes the segmentation of document content mto pomtcasts and multicasts After receiving the pomtcast of a document's page layouts, the prmter knows which multicasts, if any, to listen to Once the prmter has received the complete page layouts and objects that define the document to be printed, it can prmt the document The prmter rasteπzes and prints odd and even pages simultaneously on both sides of the sheet It contams duplexed prmt engme controllers 760 and prmt engmes utilizing Memjet™ prmtheads 350 for this purpose The printing process consists of two decoupled stages rasterization of page descnptions, and expansion and printing of page images The raster image processor (RIP) consists of one or more standard DSPs 757 running m parallel The duplexed prmt engme controllers consist of custom processors which expand, dither and prmt page images m real time, synchronized with the operation of the prmtheads m the print engmes Prmters not enabled for IR printing have the option to prmt tags usmg IR-absorptive black mk, although this restπcts tags to otherwise empty areas of the page Although such pages have more limited functionality than IR-pπnted pages, they are still classed as netpages - 14 - A normal netpage printer prints netpages on sheets of paper. More specialised netpage printers may print onto more specialised surfaces, such as globes. Each printer supports at least one surface type, and supports at least one tag tiling scheme, and hence tag map, for each surface type. The tag map 811 which describes the tag tiling scheme actually used to print a document becomes associated with that document so that the document's tags can be correctly interpreted. Figure 2 shows the netpage printer class diagram, reflecting printer-related information maintained by a registration server 11 on the netpage network. A preferred embod ment of the netpage printer is described in greater detail in Section 6 below, with reference to Figures 11 to 16. 1.5.1 Memjet™ Printheads The netpage system can operate using printers made with a wide range of digital printing technologies, including thermal inkjet, piezoelectric inkjet, laser electrophotographic, and others. However, for wide consumer acceptance, it is desirable that a netpage printer have the following characteristics: • photographic quality color printing • high quality text printing high reliability • low printer cost • low ink cost • low paper cost • simple operation • nearly silent printing • high printing speed • simultaneous double sided printing • compact form factor • low power consumption No commercially available printing technology has all of these charact πsiics. To enable to production of printers with these characteristics, the present applicant has invented a new print technology, referred to as Memjet™ technology. Memjet™ is a drop-on-demand inkjet technology that incorporates pagewidth printheads fabricated using microelectromechanical systems (MEMS) technology. Figure 17 shows a single printing element 300 of a Memjet™ printhead. The netpage wallprinter incorporates 168960 printing elements 300 to form a 1600 dpi pagewidth duplex printer. This printer simultaneously prints cyan, magenta, yellow, black, and infrared inks as well as paper conditioner and ink fixative. The printing element 300 is approximately 110 microns long by 32 microns wide. Arrays of these printing elements are formed on a silicon substrate 301 that incorporates CMOS logic, data transfer, timing, and drive circuits (not shown). Major elements of the printing element 300 are the nozzle 302, the nozzle rim 303, the nozzle chamber 304, the fluidic seal 305, the ink channel rim 306, the lever arm 307, the active actuator beam pair 308, the passive actuator beam pair 309, the active actuator anchor 310, the passive actuator anchor 311, and the ink inlet 312. The active actuator beam pair 308 is mechanically joined to the passive actuator beam pair 309 at the join 319. Both beams pairs are anchored at their respective anchor points 310 and 311. The combination of elements 308, 309, 310, 311, and 319 form a cantilevered electrothermal bend actuator 320. Figure 18 shows a small part of an array of printing elements 300, including a cross section 315 of a - 15 - pnnting element 300 The cross section 315 is shown without mk, to clearly show the ink inlet 312 that passes through the silicon wafer 301 Figures 1 (a), 19(b) and 19(c) show the operating cycle of a Memjet™ printing element 300 Figure 19(a) shows the quiescent position of the mk memscus 316 pπor to pnntmg an mk droplet Ink is retained m the nozzle chamber by surface tension at the mk memscus 316 and at the fluidic seal 305 formed between the nozzle chamber 304 and the mk channel nm 306 While pnntmg, the pπnthead CMOS circuitry distnbutes data from the prmt engme controller to the correct pnntmg element, latches the data, and buffers the data to dπve the electrodes 318 of the active actuator beam parr 308 This causes an electncal current to pass through the beam pair 308 for about one microsecond, resulting m Joule heating The temperature increase resulting from Joule heating causes the beam pair 308 to expand As the passive actuator beam pan- 309 is not heated, it does not expand, resulting m a stress difference between the two beam pairs This stress difference is partially resolved by the cantilevered end of the electrothermal bend actuator 320 bending towards the substrate 301 The lever arm 307 transmits this movement to the nozzle chamber 304 The nozzle chamber 304 moves about two microns to the position shown m Figure 19(b) This mcreases the ink pressure, forcmg ink 321 out of the nozzle 302, and causing the mk memscus 316 to bulge The nozzle nm 303 prevents the mk memscus 316 from spreading across the surface of the nozzle chamber 304 As the temperature of the beam pairs 308 and 309 equalizes, the actuator 320 returns to its ongmal position This aids m the break-off of the mk droplet 317 from the ink 321 in the nozzle chamber, as shown m Figure 19(c) The nozzle chamber is refilled by the action of the surface tension at the memscus 316 Figure 20 shows a segment of a prmthead 350 In a netpage prmter, the length of the prmthead is the full width of the paper (typically 210 mm) m the direction 351 The segment shown is 04 mm long (about 0 2% of a complete pπnthead) When pnntmg, the paper is moved past the fixed prmthead m the direction 352 The prmthead has 6 rows of mterdigitated printing elements 300, pnntmg the six colors or types of ink supplied by the mk inlets 312 To protect the fragile surface of the pπnthead duπng operation, a nozzle guard wafer 330 is attached to the pπnthead substrate 301 For each nozzle 302 there is a correspondmg nozzle guard hole 331 through which the ink droplets are fired To prevent the nozzle guard holes 331 from becommg blocked by paper fibers or other debns, filtered air is pumped through the air inlets 332 and out of the nozzle guard holes during pnntmg To prevent mk 321 from drying, the nozzle guard is sealed while the prmter is idle 1.6 The Netpage Pen The active sensmg device of the netpage system is typically a pen 101, which, usmg its embedded controller 134, is able to capture and decode IR position tags from a page via an image sensor The image sensor is a solid-state device provided with an appropnate filter to permit sensmg at only near-infrared wavelengths As descnbed m more detail below, the system is able to sense when the mb is m contact with the surface, and the pen is able to sense tags at a sufficient rate to capture human handwπting (l e at 200 dpi or greater and 100 Hz or faster) Information captured by the pen is encrypted and wirelessly transmitted to the printer (or base station), the printer or base station interpreting the data with respect to the (known) page structure The preferred embodiment of the netpage pen operates both as a normal marking mk pen and as a non- marking stylus The marking aspect, however, is not necessary for usmg the netpage system as a browsmg system, such as when it is used as an Internet mterface Each netpage pen is registered with the netpage system and has a unique pen ID 61 Figure 23 shows the netpage pen class diagram, reflecting pen-related information mamtamed by a registration server 11 on the netpage network When either mb is m contact with a netpage, the pen determines its position and onentation relative to the - 16 - page The mb is attached to a force sensor, and the force on the mb is mterpreted relative to a threshold to mdicate whether the pen is "up" or "down" This allows a mteractive element on the page to be 'clicked' by pressmg with the pen mb, m order to request, say, information from a network Furthermore, the force is captured as a continuous value to allow, say, the full dynamics of a signature to be veπfied The pen determines the position and onentation of its mb on the netpage by imaging, m the infrared spectrum, an area 193 of the page in the vicinity of the mb It decodes the nearest tag and computes the position of the mb relative to the tag from the observed perspective distortion on the imaged tag and the known geometry of the pen optics Although the position resolution of the tag may be low, because the tag density on the page is mversely proportional to the tag size, the adjusted position resolution is quite high, exceeding the minimum resolution reqmred for accurate handwnting recognition Pen actions relative to a netpage are captured as a senes of strokes A stroke consists of a sequence of time- stamped pen positions on the page, mitiated by a pen-down event and completed by the subsequent pen-up event A stroke is also tagged with the page ID 50 of the netpage whenever the page ID changes, which, under normal circumstances, is at the commencement of the stroke Each netpage pen has a current selection 826 associated with it, allowing the user to perform copy and paste operations etc The selection is timestamped to allow the system to discard it after a defined time penod The current selection descnbes a region of a page instance It consists of the most recent digital mk stroke captured through the pen relative to the background area of the page It is mterpreted m an application-specific manner once it is submitted to an application via a selection hyperlink activation Each pen has a current mb 824 This is the mb last notified by the pen to the system In the case of the default netpage pen descnbed above, either the marking black mk mb or the non-marking stylus mb is cunent Each pen also has a current mb style 825 This is the mb style last associated with the pen by an application, e g m response to the user selecting a color from a palette The default mb style is the b style associated with the current mb Strokes captured through a pen are tagged with the current mb style When the strokes are subsequently reproduced, they are reproduced m the mb style with which they are tagged Whenever the pen is within range of a printer with which it can communicate, the pen slowly flashes its "onlme" LED When the pen fails to decode a stroke relative to the page, it momentanly activates its ' eπor" LED When the pen succeeds m decoding a stroke relative to the page, it momentanly activates its "ok" LED A sequence of captured strokes is referred to as digital mk Digital ink forms the basis for the digital exchange of drawings and handwnting, for onlme recognition of handwnting, and for onlme venfication of signatures The pen is wireless and transmits digital ink to the netpage prmter via a short-range radio link The transmitted digital mk is encrypted for pnvacy and security and packetized for efficient transmission, but is always flushed on a pen-up event to ensure timely handling m the prmter When the pen is out-of-range of a prmter it buffers digital mk m internal memory, which has a capacity of over ten minutes of continuous handwnting When the pen is once again within range of a prmter, it transfers any buffered digital mk A pen can be registered with any number of printers, but because all state data resides m netpages both on paper and on the network, it is largely lmmatenal which printer a pen is communicating with at any particular time A preferred embodiment of the pen is descnbed m greater detail m Section 6 below, with reference to Figures 8 to 10 1.7 NETPAGE INTERACTION The netpage prmter 601 receives data relating to a stroke from the pen 101 when the pen is used to mteract - 17 - with a netpage 1 The coded data 3 of the tags 4 is read by the pen when it is used to execute a movement, such as a stroke The data allows the identity of the particular page and associated mteractive element to be determined and an indication of the relative positioning of the pen relative to the page to be obtained The mdicatmg data is transmitted to the prmter, where it resolves, via the DNS, the page ID 50 of the stroke mto the network address of the netpage page server 10 which mamtams the coπesponding page instance 830 It then transmits the stroke to the page server If the page was recently identified m an earlier stroke, then the prmter may already have the address of the relevant page server in its cache Each netpage consists of a compact page layout mamtamed persistently by a netpage page server (see below) The page layout refers to objects such as images, fonts and pieces of text, typically stored elsewhere on the netpage network When the page server receives the stroke from the pen, it retπeves the page descπption to which the stroke applies, and determines which element of the page descπption the stroke intersects It is then able to interpret the stroke m the context of the type of the relevant element A "click" is a stroke where the distance and time between the pen down position and the subsequent pen up position are both less than some small maximum An object which is activated by a click typically requires a click to be activated, and accordingly, a longer stroke is ignored The failure of a pen action, such as a "sloppy" click, to register is indicated by the lack of response from the pen's "ok" LED There are two lands of mput elements m a netpage page descnption hyperlinks and form fields Input through a form field can also tngger the activation of an associated hyperlink 1.7.1 Hyperlinks A hyperlink is a means of sending a message to a remote application, and typically elicits a printed response m the netpage system A hyperlink element 844 identifies the application 71 which handles activation of the hyperlink, a link ID 54 which identifies the hyperlink to the application, an "alias required" flag which asks the system to mclude the user's application alias ID 65 m the hyperlink activation, and a descπption which is used when the hyperlink is recorded as a favoπte or appears m the user's history The hyperlink element class diagram is shown m Figure 29 When a hyperlink is activated, the page server sends a request to an application somewhere on the network The application is identified by an application ID 64, and the application ID is resolved m the normal way via the DNS There are three types of hyperlinks general hyperlinks 863, form hyperlinks 865, and selection hyperlinks 864, as shown m Figure 30 A general hyperlink can implement a request for a linked document, or may simply signal a preference to a server A form hyperlink submits the corresponding form to the application A selection hyperlink submits the current selection to the application If the current selection contams a smgle-word piece of text, for example, the application may return a smgle-page document giving the word's meaning within the context m which it appears, or a translation mto a different language Each hyperlink type is characterized by what information is submitted to the application The corresponding hyperlink instance 862 records a transaction ID 55 which can be specific to the page instance on which the hyperlink instance appears The transaction ID can identify user-specific data to the application, for example a "shopping cart" of pending purchases mamtamed by a purchasing application on behalf of the user The system mcludes the pen's current selection 826 m a selection hyperlink activation The system mcludes the content of the associated form instance 868 in a form hyperlink activation, although if the hyperlink has its "submit delta" attribute set, only mput smce the last form submission is mcluded The system mcludes an effective return path m all hyperlink activations A hyperlinked group 866 is a group element 838 which has an associated hyperlink, as shown m Figure 31 - 18 - When input occurs through any field element in the group, the hyperlink 844 associated with the group is activated. A hyperlinked group can be used to associate hyperlink behavior with a field such as a checkbox. It can also be used, in conjunction with the "submit delta" attribute of a form hyperlink, to provide continuous input to an application. It can therefore be used to support a "blackboard" interaction model, i.e. where input is captured and therefore shared as soon as it occurs. 1.7.2 Forms A form defines a collection of related input fields used to capture a related set of inputs through a printed netpage. A form allows a user to submit one or more parameters to an application software program running on a server. A form 867 is a group element 838 in the document hierarchy. It ultimately contains a set of terminal field elements 839. A form instance 868 represents a printed instance of a form. It consists of a set of field instances 870 which correspond to the field elements 845 of the form. Each field instance has an associated value 871, whose type depends on the type of the corresponding field element. Each field value records input through a particular printed form instance, i.e. through one or more printed netpages. The form class diagram is shown in Figure 32. Each form instance has a status 872 which indicates whether the form is active, frozen, submitted, void or expired. A form is active when first printed. A form becomes frozen once it is signed. A form becomes submitted once one of its submission hyperlinks has been activated, unless the hyperlink has its "submit delta" attribute set. A form becomes void when the user invokes a void form, reset form or duplicate form page command. A form expires when the time the form has been active exceeds the form's specified lifetime. While the form is active, form input is allowed. Input through a form which is not active is instead captured in the background field 833 of the relevant page instance. When the form is active or frozen, form submission is allowed. Any attempt to submit a form when the form is not active or frozen is rejected, and instead elicits an form status report. Each form instance is associated (at 59) with any form instances derived from it, thus providing a version history. This allows all but the latest version of a form in a particular time period to be excluded from a search. All input is captured as digital ink. Digital ink 873 consists of a set of timestamped stroke groups 874, each of which consists of a set of styled strokes 875. Each stroke consists of a set of timestamped pen positions 876, each of which also includes pen orientation and nib force. The digital ink class diagram is -Φ.own in Figure 33. A field element 845 can be a checkbox field 877, a text field 878, a drawing field 879, or a signature field 880. The field element class diagram is shown in Figure 34. Any digital ink captured in a field's zone 58 is assigned to the field. A checkbox field has an associated boolean value 881, as shown in Figure 35. Any mark (a tick, a cross, a stroke, a fill zigzag, etc.) captured in a checkbox field's zone causes a true value to be assigned to the field's value. A text field has an associated text value 882, as shown in Figure 36. Any digital ink captured in a text field's zone is automatically converted to text via online handwriting recognition, and the text is assigned to the field's value. Online handwriting recognition is well-understood (see for example Tappert, C, CY. Suen and T. Wakahara, "The State of the Art in On-Line Handwriting Recognition", IEEE Transactions on Pattern Analysis and Machine Intelligence, Vol.12, No.8, August 1990). A signature field has an associated digital signature value 883, as shown in Figure 37. Any digital ink captured in a signature field's zone is automatically verified with respect to the identity of the owner of the pen/and a digital signature of the content of the form of which the field is part is generated and assigned to the field's value. The digital signature is generated using the pen user's private signature key specific to the application which owns the form. Online signature verification is well-understood (see for example Plamondon, R. and G. Lorette, "Automatic Signature Verification and Writer Identification - The State of the Art", Pattern Recognition, Vol.22, No.2, 1989). - 19 - A field element is hidden if its "hidden" attribute is set A hidden field element does not have an mput zone on a page and does not accept mput It can have an associated field value which is mcluded m the form data when the form containing the field is submitted "Editing" commands, such as stπke-throughs mdicatmg deletion, can also be recognized m form fields Because the handwnting recognition algonthm works "onlme" (l e with access to the dynamics of the pen movement), rather than "offline" (I e with access only to a bitmap of pen markmgs), it can recognize run-on discretely- wπtten characters with relatively high accuracy, without a wπter-dependent training phase A wπter-dependent model of handwnting is automatically generated over time, however, and can be generated up-front if necessary, Digital ink, as already stated, consists of a sequence of strokes Any stroke which starts m a particular element's zone is appended to that element's digital mk stream, ready for mterpretation Any stroke not appended to an object's digital mk stream is appended to the background field's digital mk stream Digital ink captured m the background field is mterpreted as a selection gesture Circumscnption of one or more objects is generally mterpreted as a selection of the circumscnbed objects, although the actual mterpretation is application-specific Table 2 summanses these vanous pen interactions with a netpage The system mamtams a current selection for each pen The selection consists simply of the most recent stroke captured m the background field The selection is cleared after an inactivity timeout to ensure predictable behavior The raw digital mk captured m every field is retained on the netpage page server and is optionally transmitted with the form data when the form is submitted to the application This allows the application to interrogate the raw digital mk should it suspect the ongmal conversion, such as the conversion of handwntten text This can, for example, mvolve human intervention at the application level for forms which fail certain application-specific consistency checks As an extension to this, the entire background area of a form can be designated as a drawing field The application can then decide, on the basis of the presence of digital mk outside the explicit fields of the form, to route the form to a human operator, on the assumption that the user may have indicated amendments to the filled-in fields outside of those fields Figure 38 shows a flowchart of the process of handling pen mput relative to a netpage The process consists of receivmg (at 884) a stroke from the pen, identifying (at 885) the page instance 830 to which the page ID 50 m the stroke refers, retπevmg (at 886) the page descnption 5, identifying (at 887) a formatted element 839 whose zone 58 the stroke mtersects, determining (at 888) whether the formatted element corresponds to a field element, and if so appending (at 892) the received stroke to the digital ink of the field value 871, interpreting (at 893) the accumulated digital ink of the field, and determining (at 894) whether the field is part of a hyperlinked group 866 and if so activating - 20 - (at 895) the associated hyperlink, alternatively determining (at 889) whether the formatted element corresponds to a hyperlink element and if so activating (at 895) the corresponding hyperlink, alternatively, m the absence of an mput field or hyperlink, appending (at 890) the received stroke to the digital ink of the background field 833, and copying (at 891 ) the received stroke to the current selection 826 of the current pen, as mamtamed by the registration server Figure 38a shows a detailed flowchart of step 893 m the process shown m Figure 38, where the accumulated digital mk of a field is mterpreted according to the type of the field The process consists of determining (at 896) whether the field is a checkbox and (at 897) whether the digital mk represents a checkmark, and if so assigning (at 898) a true value to the field value, alternatively determining (at 899) whether the field is a text field and if so converting (at 900) the digital mk to computer text, with the help of the appropπate registration server, and assigning (at 901) the converted computer text to the field value, alternatively determining (at 902) whether the field is a signature field and if so verifying (at 903) the digital mk as the signature of the pen's owner, with the help of the appropnate registration server, creating (at 904) a digital signature of the contents of the corresponding form, also with the help of the registration server and usmg the pen owner's pnvate signature key relating to the corresponding application, and assigning (at 905) the digital signature to the field value 1.7.3 Page Server Commands A page server command is a command which is handled locally by the page server It operates directly on form, page and document instances A page server command 907 can be a void form command 908, a duplicate form command 909, a reset form command 910, a get form status command 911, a duplicate page command 912, a reset page command 913, a get page status command 914, a duplicate document command 915, a reset document command 916, or a get document status command 917, as shown m Figure 39 A void form command voids the corresponding form instance A duplicate form command voids the correspondmg form instance and then produces an active printed copy of the current form instance with field values preserved The copy contams the same hyperlink transaction IDs as the ongmal, and so is indistinguishable from the ongmal to an application A reset form command voids the corresponding form instance and then produces an active printed copy of the form instance with field values discarded A get form status command produces a printed report on the status of the corresponding form instance, mcludmg who published it, when it was printed, for whom it was printed, and the form status of the form instance Smce a form hyperlink instance contams a transaction ID, the application has to be mvolved in producmg a new form instance A button requesting a new form instance is therefore typically implemented as a hyperlink A duplicate page command produces a printed copy of the corresponding page instance with the background field value preserved If the page contams a form or is part of a form, then the duplicate page command is mterpreted as a duplicate form command A reset page command produces a printed copy of the corresponding page instance with the background field value discarded If the page contams a form or is part of a form, then the reset page command is mterpreted as a reset form command A get page status command produces a printed report on the status of the correspondmg page instance, including who published it, when it was printed, for whom it was printed, and the status of any forms it contams or is part of The netpage logo which appears on every netpage is usually associated with a duplicate page element When a page instance is duplicated with field values preserved, field values are printed m their native form, l e a checkmark appears as a standard checkmark graphic, and text appears as typeset text Only drawings and signatures appear m their ongmal form, with a signature accompanied by a standard graphic mdicatmg successful signature venfication - 21 - A duplicate document command produces a printed copy of the corresponding document instance with background field values preserved If the document contams any forms, then the duplicate document command duplicates the forms m the same way a duplicate form command does A reset document command produces a printed copy of the corresponding document instance with background field values discarded If the document contams any forms, then the reset document command resets the forms m the same way a reset form command does A get document status command produces a printed report on the status of the corresponding document instance, mcludmg who published it, when it was printed, for whom it was printed, and the status of any forms it contams If the page server command's "on selected" attribute is set, then the command operates on the page identified by the pen's current selection rather than on the page containing the command This allows a menu of page server commands to be printed If the target page doesn't contain a page server command element for the designated page server command, then the command is ignored An application can provide application-specific handling by embedding the relevant page server command element m a hyperlinked group The page server activates the hyperlink associated with the hyperlinked group rather than executing the page server command A page server command element is hidden if its "hidden" attribute is set A hidden command element does not have an mput zone on a page and so cannot be activated directly by a user It can, however, be activated via a page server command embedded m a different page, if that page server command has its "on selected" attribute set 1.8 STANDARD FEATURES OF NETPAGES In the preferred form, each netpage is printed with the netpage logo at the bottom to mdicate that it is a netpage and therefore has mteractive properties The logo also acts as a copy button In most cases pressmg the logo produces a copy of the page h the case of a form, the button produces a copy of the entire form And m the case of a secure document, such as a ticket or coupon, the button elicits an explanatory note or advertising page The default smgle-page copy function is handled directly by the relevant netpage page server Special copy functions are handled by linking the logo button to an application 1.9 USER HELP SYSTEM In a preferred embodiment, the netpage prmter has a smgle button labelled "Help" When pressed it elicits a smgle page of information, mcludmg • status of prmter connection • status of printer consumables • top-level help menu • document function menu • top-level netpage network directory The help menu provides a hierarchical manual on how to use the netpage system The document function menu mcludes the following functions • print a copy of a document • prmt a clean copy of a form • prmt the status of a document A document function is mitiated by simply pressmg the button and then touching any page of the document The status of a document indicates who published it and when, to whom it was delivered, and to whom and when it was subsequently submitted as a form The netpage network directory allows the user to navigate the hierarchy of publications and services on the network As an alternative, the user can call the netpage network "900" number "yellow pages" and speak to a human operator The operator can locate the desired document and route it to the user's prmter Depending on the document - 22 - type, the publisher or the user pays the small "yellow pages" service fee The help page is obviously unavailable if the printer is unable to print In this case the "error" light is lit and the user can request remote diagnosis over the network 2 PERSONALIZED PUBLICATION MODEL In the following descπption, news is used as a canonical publication example to illustrate personalization mechamsms m the netpage system Although news is often used m the limited sense of newspaper and newsmagazme news, the intended scope m the present context is wider In the netpage system, the editoπal content and the advertising content of a news publication are personalized usmg different mechamsms The editoπal content is personalized according to the reader's explicitly stated and implicitly captured mterest profile The advertising content is personalized according to the reader's locality and demographic 2.1 EDITORIAL PERSONALIZATION A subscnber can draw on two lands of news sources those that deliver news publications, and those that deliver news streams While news publications are aggregated and edited by the publisher, news streams are aggregated either by a news publisher or by a specialized news aggregator News publications typically correspond to traditional newspapers and newsmagazines, while news streams can be many and vaned a "raw" news feed from a news service, a cartoon strip, a freelance wnter's column, a friend's bulletin board, or the reader's own e-mail The netpage publication server supports the publication of edited news publications as well as the aggregation of multiple news streams By handling the aggregation and hence the formatting of news streams selected directly by the reader, the server is able to place advertising on pages over which it otherwise has no editonal control The subscnber builds a daily newspaper by selecting one or more contributing news publications, and creating a personalized version of each The resulting daily editions are printed and bound together mto a smgle newspaper The vanous members of a household typically express then different mterests and tastes by selecting different daily publications and then customizing them For each publication, the reader optionally selects specific sections Some sections appear daily, while others appear weekly The daily sections available from The New York Times online for example, mclude "Page One Plus", "National", "International", "Opmion", "Busmess", "Arts/Living", "Tecimology", and "Sports" The set of available sections is specific to a publication, as is the default subset The reader can extend the daily newspaper by creating custom sections, each one drawing on any number of news streams Custom sections might be created for e-mail and friends' announcements ("Personal"), or for monitoring news feeds for specific topics ("Alerts" or "Clippings") For each section, the reader optionally specifies its size, either qualitatively (e g short, medium, or long), or numencally (l e as a limit on its number of pages), and the desired proportion of advertising, either qualitatively (e g high, normal, low, none), or numencally (1 e as a percentage) The reader also optionally expresses a preference for a large number of shorter articles or a small number of longer articles Each article is ideally wπtten (or edited) m both short and long forms to support this preference An article may also be wπtten (or edited) m different versions to match the expected sophistication of the reader, for example to provide children's and adults' versions The appropπate version is selected accordmg to the reader's age The reader can specify a "reading age" which takes precedence over then biological age The articles which make up each section are selected and pnoπtized by the editors, and each is assigned a useful lifetime By default they are delivered to all relevant subscπbers, m pπoπty order, subject to space constraints m the subscnbers' editions In sections where it is appropnate, the reader may optionally enable collaborative filtering This is then - 23 - applied to articles which have a sufficiently long lifetime. Each article which qualifies for collaborative filtermg is printed with rating buttons at the end of the article. The buttons can provide an easy choice (e.g. "liked" and "disliked'), making it more likely that readers will bother to rate the article. Articles with high priorities and short lifetimes are therefore effectively considered essential reading by the editors and are delivered to most relevant subscribers. The reader optionally specifies a serendipity factor, either qualitatively (e.g. do or don't surprise me), or numerically. A high serendipity factor lowers the threshold used for matching during collaborative filtering. A high factor makes it more likely that the corresponding section will be filled to the reader's specified capacity. A different serendipity factor can be specified for different days of the week. The reader also optionally specifies topics of particular interest within a section, and this modifies the priorities assigned by the editors. The speed of the reader's Internet connection affects the quality at which images can be delivered. The reader optionally specifies a preference for fewer images or smaller images or both. If the number or size of images is not reduced, then images may be delivered at lower quality (i.e. at lower resolution or with greater compression). At a global level, the reader specifies how quantities, dates, times and monetary values are localized. This involves specifying whether units are imperial or metric, a local timezone and time format, and a local currency, and whether the localization consist of in situ translation or annotation. These preferences are derived from the reader's locality by default. To reduce reading difficulties caused by poor eyesight, the reader optionally specifies a global preference for a larger presentation. Both text and images are scaled accordingly, and less information is accommodated on each page. The language in which a news publication is published, and its corresponding text encoding, is a property of the publication and not a preference expressed by the user. However, the netpage system can be configured to provide automatic translation services in various guises. 2.2 ADVERTISING LOCALIZATION AND TARGETING The personalization of the editorial content directly affects the advertising content, because advertising is typically placed to exploit the editorial context. Travel ads, for example, are more likely to appear in a travel section than elsewhere. The value of the editorial content to an advertiser (and therefore to the publisher) lies in its ability to attract large numbers of readers with the right demographics. Effective advertising is placed on the basis of locality and demographics. Locality determines proximity to particular services, retailers etc., and particular interests and concerns associated with the local community and environment. Demographics determine general interests and preoccupations as well as likely spending patterns. A news publisher's most profitable product is advertising "space", a multi-dimensional entity determined by the publication's geographic coverage, the size of its readership, its readership demographics, and the page area available for advertising. In the netpage system, the netpage publication server computes the approximate multi-dimensional size of a publication's saleable advertising space on a per-section basis, taking into account the publication's geographic coverage, the section's readership, the size of each reader's section edition, each reader's advertising proportion, and each reader's demographic. In comparison with other media, the netpage system allows the advertising space to be defined in greater detail, and allows smaller pieces of it to be sold separately. It therefore allows it to be sold at closer to its true value. For example, the same advertising "slot" can be sold in varying proportions to several advertisers, with - 24 - mdividual readers' pages randomly receivmg the advertisement of one advertiser or another, overall preservmg the proportion of space sold to each advertiser The netpage system allows advertismg to be linked directly to detailed product information and onlme purchasing It therefore raises the intrinsic value of the advertismg space Because personalization and localization are handled automatically by netpage publication servers, an advertismg aggregator can provide arbitrarily broad coverage of both geography and demographics The subsequent disaggregation is efficient because it is automatic. This makes it more cost-effective for publishers to deal with advertismg aggregators than to directly capture advertismg Even though the advertismg aggregator is taking a proportion of advertismg revenue, publishers may find the change profit-neutral because of the greater efficiency of aggregation The advertismg aggregator acts as an intermediary between advertisers and publishers, and may place the same advertisement m multiple publications It is worth noting that ad placement m a netpage publication can be more complex than ad placement m the publication's traditional counterpart, because the publication's advertismg space is more complex While ignoring the full complexities of negotiations between advertisers, advertismg aggregators and publishers, the preferred form of the netpage system provides some automated support for these negotiations, mcludmg support for automated auctions of advertismg space Automation is particularly desirable for the placement of advertisements which generate small amounts of mcome, such as small or highly localized advertisements Once placement has been negotiated, the aggregator captures and edits the advertisement and records it on a netpage ad server Correspondingly, the publisher records the ad placement on the relevant netpage publication server When the netpage publication server lays out each user's personalized publication, it picks the relevant advertisements from the netpage ad server. 2.3 USER PROFILES 2.3.1 Information Filtering The personalization of news and other publications relies on an assortment of user-specific profile information, mcludmg • publication customizations • collaborative filtermg vectors • contact details • presentation preferences The customization of a publication is typically publication-specific, and so the customization information is mamtamed by the relevant netpage publication server A collaborative filtermg vector consists of the user's ratings of a number of news items It is used to correlate different users' interests for the purposes of making recommendations Although there are benefits to maintaining a smgle collaborative filtermg vector independently of any particular publication, there are two reasons why it is more practical to maintain a separate vector for each publication there is likely to be more overlap between the vectors of subscπbers to the same publication than between those of subscnbers to different publications, and a publication is likely to want to present its users' collaborative filtermg vectors as part of the value of its brand, not to be found elsewhere Collaborative filtermg vectors are therefore also mamtamed by the relevant netpage publication server Contact details, mcludmg name, street address, ZIP Code, state, country, telephone numbers, are global by nature, and are mamtamed by a netpage registration server Presentation preferences, mcludmg those for quantities, dates and times, are likewise global and mamtamed m the same way The localization of advertismg relies on the locality indicated in the user's contact details, while the - 25 - targeting of advertismg relies on personal mformation such as date of birth, gender, maπtal status, mcome, profession, education, or qualitative denvatives such as age range and come range For those users who choose to reveal personal information for advertismg purposes, the information is mamtamed by the relevant netpage registration server h the absence of such information, advertismg can be targeted on the basis of the demographic associated with the user's ZIP or ZIP+4 Code Each user, pen, prmter, application provider and application is assigned its own unique identifier, and the netpage registration server mamtams the relationships between them, as shown m Figures 21, 22, 23 and 24 For registration purposes, a publisher is a special land of application provider, and a publication is a special land of application Each user 800 may be authorized to use any number of prmters 802, and each printer may allow any number of users to use it Each user has a smgle default prmter (at 66), to which peπodical publications are delivered by default, whilst pages printed on demand are delivered to the prmter through which the user is interacting The server keeps track of which publishers a user has authorized to prmt to the user's default prmter A publisher does not record the ID of any particular prmter, but instead resolves the ID when it is required When a user subscπbes 808 to a publication 807, the publisher 806 (l e application provider 803) is authorized to prmt to a specified printer or the user's default printer This authorization can be revoked at any time by the user Each user may have several pens 801, but a pen is specific to a smgle user If a user is authorized to use a particular prmter, then that prmter recognizes any of the user's pens The pen ID is used to locate the corresponding user profile mamtamed by a particular netpage registration server, via the DNS m the usual way A Web termmal 809 can be authorized to print on a particular netpage prmter, allowing Web pages and netpage documents encountered duπng Web browsmg to be conveniently printed on the nearest netpage prmter The netpage system can collect, on behalf of a prmter provider, fees and commissions on mcome earned through publications printed on the provider's prmters Such mcome can mclude advertismg fees, click-through fees, e- commerce commissions, and transaction fees If the prmter is owned by the user, then the user is the prmter provider Each user also has a netpage account 820 which is used to accumulate micro-debits and credits (such as those descnbed m the preceding paragraph), contact details 815, mcludmg name, address and telephone numbers, global preferences 816, mcludmg pnvacy, delivery and localization settings, any number of biometnc records 817, containing the user's encoded signature 818, fingerprint 819 etc, a handwnting model 819 automatically mamtamed by the system, and SET payment card accounts 821 with which e-commerce payments can be made 2.3.2 Favorites List A netpage user can maintain a list 922 of "favontes" - links to useful documents etc on the netpage network The list is mamtamed by the system on the user's behalf It is organized as a hierarchy of folders 924, a preferrred embodiment of which is shown m the class diagram m Figure 41 2.3.3 History List The system mamtams a history list 929 on each user's behalf, containing links to documents etc accessed by the user through the netpage system It is organized as a date-ordered list, a preferred embodiment of which is shown m the class diagram m Figure 42 2.4 INTELLIGENT PAGE LAYOUT The netpage publication server automatically lays out the pages of each user's personalized publication on a section-by-section basis Smce most advertisements are m the form of pre-formatted rectangles, they are placed on the page before the editonal content The advertismg ratio for a section can be achieved with wildly varying advertismg ratios on individual ■ 26 - pages withm the section, and the ad layout algonthm exploits this The algonfhm is configured to attempt to co-locate closely tied editoπal and advertismg content, such as placing ads for roofing mateπal specifically withm the publication because of a special feature on do-it-yourself roofing repairs The editoπal content selected for the user, mcludmg text and associated images and graphics, is then laid out according to vaπous aesthetic rules The entire process, mcludmg the selection of ads and the selection of editonal content, must be iterated once the layout has converged, to attempt to more closely achieve the user's stated section size preference The section size preference can, however, be matched on average over time, allowing significant day-to-day vaπations 2.5 DOCUMENT FORMAT Once the document is laid out, it is encoded for efficient distπbution and persistent storage on the netpage network The primary efficiency mechanism is the separation of mformation specific to a smgle user's edition and information shared between multiple users' editions The specific mformation consists of the page layout The shared information consists of the objects to which the page layout refers, mcludmg images, graphics, and pieces of text A text object contams fully-formatted text represented m the Extensible Markup Language (XML) usmg the Extensible Stylesheet Language (XSL) XSL provides precise control over text formatting independently of the region mto which the text is bemg set, which m this case is bemg provided by the layout The text object contams embedded language codes to enable automatic translation, and embedded hyphenation hints to aid with paragraph formatting An image object encodes an image m the JPEG 2000 wavelet-based compressed image format A graphic object encodes a 2D graphic m Scalable Vector Graphics (SVG) format The layout itself consists of a seπes of placed image and graphic objects, linked textflow objects through which text objects flow, hyperlinks and mput fields as descπbed above, and watermark regions These layout objects are summarized in Table 3 The layout uses a compact format suitable for efficient distribution and storage 2.6 DOCUMENT DISTRIBUTION As descnbed above, for purposes of efficient distribution and persistent storage on the netpage network, a user-specific page layout is separated from the shared objects to which it refers When a subscπbed publication is ready to be distnbuted, the netpage publication server allocates, with the help of the netpage ID server 12, a unique ID for each page, page instance, document, and document instance The server computes a set of optimized subsets of the shared content and creates a multicast channel for - 27 - each subset, and then tags each user-specific layout with the names of the multicast channels which will carry the shared content used by that layout The server then pointcasts each user's layouts to that user's prmter via the appropπate page server, and when the pointcasting is complete, multicasts the shared content on the specified channels After receivmg its pomtcast, each page server and prmter subscnbes to the multicast channels specified m the page layouts During the multicasts, each page server and prmter extracts from the multicast streams those objects refeπed to by its page layouts The page servers persistently archive the received page layouts and shared content Once a prmter has received all the objects to which its page layouts refer, the prmter re-creates the fully- populated layout and then rasteπzes and prints it Under normal circumstances, the prmter prints pages faster than they can be delivered Assuming a quarter of each page is covered with images, the average page has a size of less than 400KB The prmter can therefore hold in excess of 100 such pages m its internal 64MB memory, allowmg for temporary buffers etc The prmter prints at a rate of one page per second This is equivalent to 400KB or about 3Mbit of page data per second, which is similar to the highest expected rate of page data delivery over a broadband network Even under abnormal cncumstances, such as when the prmter runs out of paper, it is likely that the user will be able to replenish the paper supply before the printer' s 100-page internal storage capacity is exhausted However, if the printer' s internal memory does fill up, then the printer will be unable to make use of a multicast when it first occurs The netpage publication server therefore allows prmters to submit requests for re- multicasts When a cntical number of requests is received or a timeout occurs, the server re-multicasts the correspondmg shared objects Once a document is printed, a printer can produce an exact duplicate at any time by retrieving its page layouts and contents from the relevant page server 2.7 ON-DEMAND DOCUMENTS When a netpage document is requested on demand, it can be personalized and delivered m much the same way as a peπodical However, smce there is no shared content, delivery is made dnectly to the requesting prmter without the use of multicast When a non-netpage document is requested on demand, it is not personalized, and it is delivered via a designated netpage formatting server which reformats it as a netpage document A netpage formatting server is a special instance of a netpage publication server The netpage formatting server has knowledge of vanous Internet document formats, mcludmg Adobe's Portable Document Format (PDF), and Hypertext Markup Language (HTML) In the case of HTML, it can make use of the higher resolution of the printed page to present Web pages m a multi-column format, with a table of contents It can automatically mclude all Web pages directly linked to the requested page The user can tune this behavior via a preference The netpage formatting server makes standard netpage behavior, mcludmg interactivity and persistence, available on any Internet document, no matter what its ongm and format It hides knowledge of different document formats from both the netpage prmter and the netpage page server, and hides knowledge of the netpage system from Web servers 3 SECURITY 3.1 CRYPTOGRAPHY Cryptography is used to protect sensitive information, both m storage and m transit, and to authenticate parties to a transaction There are two classes of cryptography m widespread use secret-key cryptography and public-key cryptography The netpage network uses both classes of cryptography Secret-key cryptography, also referred to as symmetic cryptography, uses the same key to encrypt and decrypt a message Two parties wishing to exchange messages must first arrange to securely exchange the secret key - 28 - Public-key cryptography, also refeπed to as asymmetnc cryptography, uses two encryption keys The two keys are mathematically related m such a way that any message encrypted usmg one key can only be decrypted usmg the other key One of these keys is then published, while the other is kept pnvate The public key is used to encrypt any message mtended for the holder of the pnvate key Once encrypted usmg the public key, a message can only be decrypted usmg the pnvate key Thus two parties can securely exchange messages without first havmg to exchange a secret key To ensure that the pnvate key is secure, it is normal for the holder of the pπvate key to generate the key pair Public-key cryptography can be used to create a digital signature The holder of the pπvate key can create a known hash of a message and then encrypt the hash usmg the pnvate key Anyone can then venfy that the encrypted hash constitutes the "signature" of the holder of the pnvate key with respect to that particular message by decrypting the encrypted hash usmg the public key and venfymg the hash against the message If the signature is appended to the message, then the recipient of the message can venfy both that the message is genuine and that it has not been altered m transit To make public-key cryptography work, there has to be a way to distribute public keys which prevents impersonation This is normally done usmg certificates and certificate authonties A certificate authonty is a trusted third party which authenticates the connection between a public key and someone's identity The certificate authonty venfies the person's identity by examining identity documents, and then creates and signs a digital certificate containing the person's identity details and public key Anyone who trusts the certificate authonty can use the public key m the certificate with a high degree of certainty that it is genuine They just have to venfy that the certificate has mdeed been signed by the certificate authonty, whose public key is well-known In most transaction environments, public-key cryptography is only used to create digital signatures and to securely exchange secret session keys Secret-key cryptography is used for all other purposes In the following discussion, when reference is made to the secure transmission of mformation between a netpage printer and a server, what actually happens is that the prmter obtains the server's certificate, authenticates it with reference to the certificate authonty, uses the public key-exchange key m the certificate to exchange a secret session key with the server, and then uses the secret session key to encrypt the message data A session key, by definition, can have an arbitranly short lifetime 3.2 NETPAGE PRINTER SECURITY Each netpage prmter is assigned a pair of unique identifiers at time of manufacture which are stored m read-only memory m the prmter and m the netpage registration server database The first ID 62 is public and uniquely identifies the prmter on the netpage network The second ID is secret and is used when the prmter is first registered on the network When the prmter connects to the netpage network for the first time after installation, it creates a signature pubhc/pnvate key pair It transmits the secret ED and the public key securely to the netpage registration server The server compares the secret ID against the printer' s secret ID recorded m its database, and accepts the registration if the IDs match It then creates and signs a certificate containing the printer' s public ID and public signature key, and stores the certificate m the registration database The netpage registration server acts as a certificate authonty for netpage prmters, smce it has access to secret information allowmg it to venfy printer identity When a user subscnbes to a publication, a record is created m the netpage registration server database authorizing the publisher to prmt the publication to the user's default prmter or a specified prmter Every document sent to a prmter via a page server is addressed to a particular user and is signed by the publisher usmg the publisher's pnvate signature key The page server venfies, via the registration database, that the publisher is authorized to deliver the - 29 - pubhcation to the specified user The page server venfies the signature usmg the publisher's public key, obtamed from the publisher's certificate stored m the registration database The netpage registration server accepts requests to add printing authorizations to the database, so long as those requests are mitiated via a pen registered to the prmter 3.3 NETPAGE PEN SECURITY Each netpage pen is assigned a unique identifier at time of manufacture which is stored m read-only memory m the pen and m the netpage registration server database The pen ID 61 umquely identifies the pen on the netpage network A netpage pen can "know" a number of netpage prmters, and a prmter can "know" a number of pens A pen communicates with a prmter via a radio frequency signal whenever it is withm range of the prmter Once a pen and prmter are registered, they regularly exchange session keys Whenever the pen transmits digital ink to the printer, the digital mk is always encrypted usmg the appropπate session key Digital mk is never transmitted in the clear A pen stores a session key for every prmter it knows, mdexed by prmter ED, and a prmter stores a session key for every pen it knows, mdexed by pen ED Both have a large but finite storage capacity for session keys, and will forget a session key on a least-recently-used basis if necessary When a pen comes withm range of a p mter, the pen and prmter discover whether they know each other If they don't know each other, then the prmter determines whether it is supposed to know the pen This might be, for example, because the pen belongs to a user who is registered to use the prmter If the prmter is meant to know the pen but doesn't, then it nutates the automatic pen registration procedure If the prmter isn't meant to know the pen, then it agrees with the pen to ignore it until the pen is placed m a charging cup, at which time it initiates the registration procedure In addition to its public ED, the pen contams a secret key-exchange key The key-exchange key is also recorded m the netpage registration server database at time of manufacture EΛu ng registration, the pen transmits its pen ID to the prmter, and the prmter transmits the pen ED to the netpage registration server The server generates a session key for the prmter and pen to use, and securely transmits the session key to the prmter It also transmits a copy of the session key encrypted with the pen's key-exchange key The prmter stores the session key internally, mdexed by the pen ED, and transmits the encrypted session key to the pen The pen stores the session key internally, mdexed by the prmter ED Although a fake pen can impersonate a pen m the pen registration protocol, only a real pen can decrypt the session key transmitted by the prmter When a previously unregistered pen is first registered, it is of limited use until it is linked to a user A registered but "un-owned" pen is only allowed to be used to request and fill m netpage user and pen registration forms, to register a new user to which the new pen is automatically hnked, or to add a new pen to an existing user The pen uses secret-key rather than public-key encryption because of hardware performance constraints m the pen 3.4 SECURE DOCUMENTS The netpage system supports the delivery of secure documents such as tickets and coupons The netpage prmter mcludes a facility to print watermarks, but will only do so on request from publishers who are suitably authorized The publisher mdicates its authonty to pnnt watermarks m its certificate, which the prmter is able to authenticate The "watermark" pnntmg process uses an alternative dither matnx m specified "watermark" regions of the page Back-to-back pages contain mirror-image watermark regions which comcide when printed The dither matrices used m odd and even pages' watermark regions are designed to produce an interference effect when the regions are - 30 - viewed together, achieved by looking through the printed sheet The effect is similar to a watermark m that it is not visible when looking at only one side of the page, and is lost when the page is copied by normal means Pages of secure documents cannot be copied usmg the built-in netpage copy mechanism descnbed m Section 1 9 above This extends to copying netpages on netpage-aware photocopiers Secure documents are typically generated as part of e-commerce transactions They can therefore mclude the user's photograph which was captured when the user registered biometπc information with the netpage registration server, as descπbed m Section 2 When presented with a secure netpage document, the recipient can venfy its authenticity by requesting its status m the usual way The unique ED of a secure document is only valid for the lifetime of the document, and secure document EDs are allocated non-contiguously to prevent then" prediction by opportumstic forgers A secure document venfication pen can be developed with bmlt-m feedback on venfication failure, to support easy pomt-of-presentation document venfication Clearly neither the watermark nor the user's photograph are secure m a cryptographic sense They simply provide a significant obstacle to casual forgery Onlme document venfication, particularly usmg a venfication pen, provides an added level of secunty where it is needed, but is still not entirely immune to forgenes 3.5 NON-REPUDIATION In the netpage system, forms submitted by users are delivered reliably to forms handlers and are persistently archived on netpage page servers It is therefore impossible for recipients to repudiate delivery E-commerce payments made through the system, as descnbed m Section 4, are also impossible for the payee to repudiate 4 ELECTRONIC COMMERCE MODEL 4.1 SECURE ELECTRONIC TRANSACTION (SET) The netpage system uses the Secure Electronic Transaction (SET) system as one of its payment systems SET, having been developed by MasterCard and Visa, is organized around payment cards, and this is reflected m the terminology However, much of the system is mdependent of the type of accounts bemg used In SET, cardholders and merchants register with a certificate auttwiity and are issued with certificates containing then public signature keys The certificate authonty venfies a cardholder's registration details with the card issuer as appropnate, and venfies a merchant's registration details with the acquirer as appropπate Cardholders and merchants store then respective pπvate signature keys securely on then computers Duπng the payment process, these certificates are used to mutually authenticate a merchant and cardholder, and to authenticate them both to the payment gateway SET has not yet been adopted widely, partly because cardholder maintenance of keys and certificates is considered burdensome Interim solutions which maintain cardholder keys and certificates on a server and give the cardholder access via a password have met with some success 4.2 SET PAYMENTS In the netpage system the netpage registration server acts as a proxy for the netpage user (l e the cardholder) m SET payment transactions The netpage system uses biometrics to authenticate the user and authorize SET payments Because the system is pen-based, the biometnc used is the user's on-lme signature, consisting of time- varying pen position and pressure A fingerprint biometnc can also be used by designing a fingerprint sensor mto the pen, although at a higher cost The type of biometπc used only affects the capture of the biometnc, not the authorization aspects of the system The first step to bemg able to make SET payments is to register the user's biometnc with the netpage - 31 - registration server. This is done m a controlled environment, for example a bank, where the biometπc can be captured at the same time as the user's identity is veπfied The biometπc is captured and stored m the regisfration database, lmked to the user's record The user's photograph is also optionally captured and lmked to the record The SET cardholder registration process is completed, and the resulting pπvate signature key and certificate are stored m the database The user's payment card mformation is also stored, giving the netpage registration server enough information to act as the user's proxy m any SET payment transaction When the user eventually supplies the biometπc to complete a payment, for example by signing a netpage order form, the prmter securely transmits the order information, the pen ED and the biometπc data to the netpage registration server The server venfies the biometnc with respect to the user identified by the pen ED, and from then on acts as the user's proxy m completing the SET payment transaction 4.3 MICRO-PAYMENTS The netpage system mcludes a mechanism for micro-payments, to allow the user to be conveniently charged for pnntmg low-cost documents on demand and for copymg copynght documents, and possibly also to allow the user to be reimbursed for expenses incurred m pnntmg advertismg matenal The latter depends on the level of subsidy already provided to the user When the user registers for e-commerce, a network account is established which aggregates micro- payments The user receives a statement on a regular basis, and can settle any outstanding debit balance usmg the standard payment mechanism The network account can be extended to aggregate subscnption fees for penodicals, which would also otherwise be presented to the user m the form of individual statements 4.4 TRANSACTIONS When a user requests a netpage m a particular application context, the application is able to embed a user- specific transaction ED 55 m the page Subsequent mput through the page is tagged with the transaction ED, and the application is thereby able to establish an appropπate context for the user's mput When mput occurs through a page which is not user-specific, however, the application must use the user's unique identity to establish a context A typical example mvolves adding items from a pre-pnnted catalog page to the user's virtual "shopping cart" To protect the user's pnvacy, however, the unique user ED 60 known to the netpage system is not divulged to applications This is to prevent different application providers from easily correlating independently accumulated behavioral data The netpage registration server mstead mamtams an anonymous relationship between a user and an application via a unique alias ED 65, as shown m Figure 24 Whenever the user activates a hyperlink tagged with the "registered" attπbute, the netpage page server asks the netpage registration server to translate the associated application ED 64, together with the pen ED 61 , mto an alias ED 65 The alias ED is then submitted to the hyperlink's application The application mamtams state information mdexed by alias ED, and is able to retπeve user-specific state mformation without knowledge of the global identity of the user The system also mamtams an independent certificate and pnvate signature key for each of a user's applications, to allow it to sign application transactions on behalf of the user usmg only application-specific mformation To assist the system m routing product bar code (UPC) "hyperlink" activations, the system records a favonte application on behalf of the user for any number of product types Each application is associated with an application provider, and the system mamtams an account on behalf of each application provider, to allow it to credit and debit the provider for click-through fees etc An application provider can be a publisher of penodical subscnbed content The system records the user's willingness to receive the subscnbed publication, as well as the expected frequency of publication - 32 - 4.5 RESOURCE DESCRIPTIONS AND COPYRIGHT A preferred embodiment of a resource descπption class diagram is shown m Figure 40 Each document and content object may be descnbed by one or more resource descnptions 842 Resource descnptions use the Dublin Core metadata element set, which is designed to facilitate discovery of electronic resources Dublin Core metadata conforms to the World Wide Web Consortium (W3C) Resource Descπption Framework (RDF) A resource descπption may identify πghts holders 920 The netpage system automatically transfers copyright fees from users to nghts holders when users prmt copyπght content 5 COMMUNICATIONS PROTOCOLS A communications protocol defines an ordered exchange of messages between entities In the netpage system, entities such as pens, printers and servers utilise a set of defined protocols to cooperatively handle user interaction with the netpage system Each protocol is illustrated by way of a sequence diagram m which the horizontal dimension is used to represent message flow and the vertical dimension is used to represent time Each entity is represented by a rectangle containing the name of the entity and a vertical column representing the lifeline of the entity Duπng the time an entity exists, the lifeline is shown as a dashed lme Duπng the time an entity is active, the lifeline is shown as a double lme Because the protocols considered here do not create or destroy entities, lifelmes are generally cut short as soon as an entity ceases to participate m a protocol 5.1 SUBSCRIPTION DELIVERY PROTOCOL A preferred embodiment of a subscnption delivery protocol is shown m Figure 43 A large number of users may subscnbe to a penodical publication Each user's edition may be laid out differently, but many users' editions will share common content such as text objects and image objects The subscnption delivery protocol therefore delivers document structures to individual prmters via pomtcast, but delivers shared content objects via multicast The application (l e publisher) first obtains a document ED 51 for each document from an ED server 12 It then sends each document structure, mcludmg its document ED and page descnptions, to the page server 10 responsible for the document's newly allocated ED It mcludes its own application ED 64, the subscπber's alias ED 65, and the relevant set of multicast channel names It signs the message usmg its pnvate signature key The page server uses the application ED and alias ED to obtain from the registration server the corresponding user ED 60, the user's selected prmter D 62 (which may be explicitly selected for the application, or may be the user's default prmter), and the application's certificate The application's certificate allows the page server to venfy the message signature The page server's request to the registration server fails if the application ED and alias ED don't together identify a subscnption 808 The page server then allocates document and page instance IDs and forwards the page descπptions, mcludmg page EDs 50, to the prmter It mcludes the relevant set of multicast channel names for the prmter to listen to It then returns the newly allocated page EDs to the application for future reference Once the application has distnbuted all of the document structures to the subscnbers' selected prmters via the relevant page servers, it multicasts the vanous subsets of the shared objects on the previously selected multicast channels Both page servers and printers momtor the appropnate multicast channels and receive then reqmred content objects They are then able to populate the previously pomtcast document structures This allows the page servers to add complete documents to then databases, and it allows the prmters to prmt the documents 5.2 HYPERLINK ACTIVATION PROTOCOL A prefeπed embodiment of a hyperlink activation protocol is shown m Figure 45 When a user clicks on a netpage with a netpage pen, the pen communicates the click to the nearest netpage - 33 - pnnter 601 The click identifies the page and a location on the page The prmter already knows the ED 61 of the pen from the pen connection protocol The prmter determines, via the DNS, the network address of the page server 10a handling the particular page ID 50 The address may already be m its cache if the user has recently mteracted with the same page The prmter then forwards the pen ED, its own prmter ED 62, the page ED and click location to the page server The page server loads the page descnption 5 identified by the page ED and determines which mput element's zone 58, if any, the click lies m Assuming the relevant mput element is a hyperlink element 844, the page server then obtains the associated application ED 64 and link ED 54, and determines, via the DNS, the network address of the application server hosting the application 71 The page server uses the pen ED 61 to obtain the correspondmg user _D 60 from the registration server 11, and then allocates a globally umque hyperlmk request ED 52 and builds a hyperlink request 934 The hyperlmk request class diagram is shown m Figure 44 The hyperlmk request records the EDs of the requesting user and prmter, and identifies the clicked hyperlmk instance 862 The page server then sends its own server ED 53, the hyperlmk request ED, and the link ED to the application The application produces a response document accordmg to application-specific logic, and obtains a document ED 51 from an ED server 12 It then sends the document to the page server 10b responsible for the document's newly allocated ID, together with the requesting page server's ED and the hyperlink request ED The second page server sends the hyperlmk request ED and application ED to the first page server to obtain the correspondmg user ED and prmter ED 62 The first page server rejects the request if the hyperlink request has expired or is for a different application The second page server allocates document instance and page EDs 50, returns the newly allocated page EDs to the application, adds the complete document to its own database, and finally sends the page descnptions to the requesting prmter The hyperlink instance may mclude a meaningful transaction ED 55, m which case the first page server mcludes the transaction ED m the message sent to the application This allows the application to establish a transaction- specific context for the hyperlmk activation If the hyperlmk requnes a user alias, 1 e its "alias reqmred" attribute is set, then the first page server sends both the pen ED 61 and the hyperlink's application ED 64 to the registration server 11 to obtain not just the user ED correspondmg to the pen ED but also the alias ID 65 corresponding to the application ID and the user ED It mcludes the alias ED m the message sent to the application, allowmg the application to establish a user-specific context for the hyperlink activation 5.3 HANDWRITING RECOGNITION PROTOCOL When a user draws a stroke on a netpage with a netpage pen, the pen communicates the stroke to the nearest netpage prmter The stroke identifies the page and a path on the page The prmter forwards the pen D 61, its own printer JD 62, the page ED 50 and stroke path to the page server 10 m the usual way The page server loads the page descπption 5 identified by the page ED and determines which mput element's zone 58, if any, the stroke mtersects Assuming the relevant mput element is a text field 878, the page server appends the stroke to the text field's digital mk After a penod of inactivity m the zone of the text field, the page server sends the pen ED and the pending strokes to the registration server 11 for mterpretation The registration server identifies the user correspondmg to the pen, and uses the user's accumulated handwnting model 822 to interpret the strokes as handwntten text Once it has - 34 - converted the strokes to text, the registration server returns the text to the requesting page server The page server appends the text to the text value of the text field 5.4 SIGNATURE VERIFICATION PROTOCOL Assuming the mput element whose zone the stroke intersects is a signature field 880, the page server 10 appends the stroke to the signature field's digital mk After a peπod of inactivity m the zone of the signature field, the page server sends the pen ID 61 and the pendmg strokes to the registration server 11 for venfication It also sends the application ID 64 associated with the form of which the signature field is part, as well as the form ED 56 and the current data content of the form The registration server identifies the user coπesponding to the pen, and uses the user's dynamic signature biometnc 818 to venfy the sfrokes as the user's signature Once it has venfied the signature, the registration server uses the application ED 64 and user ED 60 to identify the user's application-specific pπvate signature key It then uses the key to generate a digital signature of the form data, and returns the digital signature to the requesting page server The page server assigns the digital signature to the signature field and sets the associated form's status to frozen The digital signature mcludes the alias ED 65 of the corresponding user This allows a smgle form to capture multiple users' signatures 5.5 FORM SUBMISSION PROTOCOL A preferred embodiment of a form submission protocol is shown m Figure 46 Form submission occurs via a form hyperlink activation It thus follows the protocol defined m Section 5 2, with some form-specific additions In the case of a form hyperlmk, the hyperlink activation message sent by the page server 10 to the application 71 also contams the form ED 56 and the current data content of the form If the form contams any signature fields, then the application venfies each one by extracting the alias ED 65 associated with the correspondmg digital signature and obtaining the correspondmg certificate from the registration server 11 5.6 COMMISSION PAYMENT PROTOCOL A preferred embodiment of a commission payment protocol is shown m Figure 47 In an e-commerce envnonment, fees and commissions may be payable from an application provider to a publisher on chck-throughs, transactions and sales Commissions on fees and commissions on commissions may also be payable from the publisher to the provider of the prmter The hyperlink request ED 52 is used to route a fee or commission credit from the target application provider 70a (e g merchant) to the source application provider 70b (I e publisher), and from the source application provider 70b to the prmter provider 72 The target application receives the hyperlmk request ED from the page server 10 when the hyperlmk is first activated, as descnbed m Section 5 2 When the target application needs to credit the source application provider, it sends the application provider credit to the ongmal page server together with the hyperlink request ED The page server uses the hyperlmk request ED to identify the source application, and sends the credit on to the relevant registration server 11 together with the source application ED 64, its own server ED 53, and the hyperlmk request ED The registration server credits the corresponding application provider's account 827 It also notifies the application provider If the application provider needs to credit the prmter provider, it sends the prmter provider credit to the ongmal page server together with the hyperlink request ED The page server uses the hyperlink request ED to identify the prmter, and sends the credit on to the relevant regisfration server together with the prmter ED The registration server credits the corresponding printer provider account 814 The source application provider is optionally notified of the identity of the target application provider, and the prmter provider of the identity of the source application provider - 35 - 6. NETPAGE PEN DESCRIPTION 6.1 PEN MECHANICS Referring to Figures 8 and 9, the pen, generally designated by reference numeral 101, mcludes a housmg 102 m the form of a plastics moulding having walls 103 defining an mtenor space 104 for mounting the pen components The pen top 105 is m operation rotatably mounted at one end 106 of the housmg 102 A semi-transparent cover 107 is secured to the opposite end 108 of the housmg 102 The cover 107 is also of moulded plastics, and is formed from semi-transparent matenal m order to enable the user to view the status of the LED mounted withm the housmg 102 The cover 107 mcludes a mam part 109 which substantially surrounds the end 108 of the housmg 102 and a projecting portion 110 which projects back from the mam part 109 and fits within a corresponding slot 111 formed m the walls 103 of the housmg 102 A radio antenna 112 is mounted behind the projecting portion 110, withm the housmg 102 Screw threads 113 surrounding an aperture 113A on the cover 107 are arranged to receive a metal end piece 114, mcludmg corresponding screw threads 115 The metal end piece 114 is removable to enable mk cartπdge replacement Also mounted withm the cover 107 is a tn-color status LED 116 on a flex PCB 117 The antenna 112 is also mounted on the flex PCB 117 The status LED 116 is mounted at the top of the pen 101 for good all-around visibility The pen can operate both as a normal marking mk pen and as a non-marking stylus An mk pen cartridge 118 with mb 119 and a stylus 120 with stylus mb 121 are mounted side by side within the housmg 102 Either the ink cartπdge mb 119 or the stylus mb 121 can be brought forward through open end 122 of the metal end piece 114, by rotation of the pen top 105 Respective slider blocks 123 and 124 are mounted to the mk cartridge 118 and stylus 120, respectively A rotatable cam barrel 125 is secured to the pen top 105 m operation and arranged to rotate therewith The cam banel 125 mcludes a cam 126 m the form of a slot withm the walls 181 of the cam barrel Cam followers 127 and 128 projecting from slider blocks 123 and 124 fit withm the cam slot 126 On rotation of the cam barrel 125, the slider blocks 123 or 124 move relative to each other to project either the pen mb 119 or stylus mb 121 out through the hole 122 m the metal end piece 114 The pen 101 has three states of operation By turning the top 105 through 90° steps, the three states are • Stylus 120 mb 121 out, • Ink cartridge 118 b 119 out, and Neither ink cartπdge 118 nιb 119 outnor stylus 120 mb 121 out A second flex PCB 129, is mounted on an electronics chassis 130 which sits withm the housmg 102 The second flex PCB 129 mounts an infrared LED 131 for providing infrared radiation for projection onto the surface An image sensor 132 is provided mounted on the second flex PCB 129 for receivmg reflected radiation from the surface The second flex PCB 129 also mounts a radio frequency chip 133, which mcludes an RF transmitter and RF receiver, and a controller chip 134 for controlling operation of the pen 101 An optics block 135 (formed from moulded clear plastics) sits withm the cover 107 and projects an infrared beam onto the surface and receives images onto the image sensor 132 Power supply wires 136 connect the components on the second flex PCB 129 to battery contacts 137 which are mounted within the cam barrel 125 A termmal 138 connects to the battery contacts 137 and the cam barrel 125 A three volt rechargeable battery 139 sits within the cam barrel 125 m contact with the battery contacts An induction charging coil 140 is mounted about the second flex PCB 129 to enable recharging of the battery 139 via induction The second flex PCB 129 also mounts an infrared LED 143 and infrared photodiode 144 for detecting displacement m the cam banel 125 when either the stylus 120 or the mk cartridge 118 is used for wnting, m order to enable a determination of the force bemg applied to the surface by the pen mb 119 or stylus mb 121 The IR photodiode 144 detects light from the ER LED 143 via reflectors (not shown) mounted on the slider blocks 123 and 124 Rubber gnp pads 141 and 142 are provided towards the end 108 of the housmg 102 to assist gnpping the pen 101, and top 105 also mcludes a clip 142 for clipping the pen 101 to a pocket - 36 - 6.2 PEN CONTROLLER The pen 101 is arranged to determine the position of its mb (stylus mb 121 or ink cartridge mb 119) by imaging, m the infrared spectrum, an area of the surface m the vicinity of the b It records the location data from the nearest location tag, and is arranged to calculate the distance of the mb 121 or 119 from the location tab utilismg optics 135 and confroller chip 134 The controller chip 134 calculates the oπentation of the pen and the nib-to-tag distance from the perspective distortion observed on the imaged tag Utilismg the RF chip 133 and antenna 112 the pen 101 can transmit the digital ink data (which is encrypted for secunty and packaged for efficient transmission) to the computing system When the pen is m range of a receiver, the digital mk data is transmitted as it is formed When the pen 101 moves out of range, digital mk data is buffered withm the pen 101 (the pen 101 circuitry mcludes a buffer ananged to store digital mk data for approximately 12 minutes of the pen motion on the surface) and can be transmitted later The confroller chip 134 is mounted on the second flex PCB 129 m the pen 101 Figure 10 is a block diagram illustrating m more detail the architecture of the confroller chip 134 Figure 10 also shows representations of the RF chip 133, the image sensor 132, the tn-color status LED 116, the ER iUummation LED 131, the ER force sensor LED 143, and the force sensor photodiode 144 The pen confroller chip 134 mcludes a controlling processor 145 Bus 146 enables the exchange of data between components of the controller chip 134 Flash memory 147 and a 512 KB DRAM 148 are also mcluded An analog-to-digital converter 149 is arranged to convert the analog signal from the force sensor photodiode 144 to a digital signal An image sensor mterface 152 interfaces with the image sensor 132 A transceiver controller 153 and base band en cuit 154 are also mcluded to mterface with the RF chip 133 which mcludes an RF circuit 155 and RF resonators and inductors 156 connected to the antenna 112 The controlling processor 145 captures and decodes location data from tags from the surface via the unage sensor 132, momtors the force sensor photodiode 144, controls the LEDs 116, 131 and 143, and handles short-range radio communication via the radio transceiver 153 It is a medium-performance (~40MHz) general-purpose RISC processor The processor 145, digital transceiver components (transceiver controller 153 and baseband cncuit 154), image sensor mterface 152, flash memory 147 and 512KB DRAM 148 are integrated m a smgle confroller ASIC Analog RF components (RF cncuit 155 and RF resonators and mductors 156) are provided m the separate RF chip The image sensor is a 215x215 pixel CCD (such a sensor is produced by Matsushita Electronic Corporation, and is descnbed m a paper by Itakura, K T Nobusada, N Okusenya, R Nagayoshi, and M Ozaki, "A 1mm 50k-Pιxel IT CCD Image Sensor for Miniature Camera System", EEEE Transactions on Electronic Devices, Volt 47, number 1, January 2000, which is incorporated herem by reference) with an IR filter The confroller ASIC 134 enters a quiescent state after a penod of inactivity when the pen 101 is not m contact with a surface It incorporates a dedicated circuit 150 which momtors the force sensor photodiode 144 and wakes up the controller 134 via the power manager 151 on a pen-down event The radio transceiver communicates m the unlicensed 900MHz band normally used by cordless telephones, or alternatively m the unlicensed 2 4GHz mdustnal, scientific and medical (ISM) band, and uses frequency hoppmg and collision detection to provide interference-free communication In an alternative embodiment, the pen incorporates an Infrared Data Association (IrDA) mterface for short- range communication with a base station or netpage prmter In a further embodiment, the pen 101 mcludes a pair of orthogonal accelerometers mounted m the normal - 37 - plane of the pen 101 axis The accelerometers 190 are shown m Figures 9 and 10 m ghost outline The provision of the accelerometers enables this embodiment of the pen 101 to sense motion without reference to surface location tags, allowmg the location tags to be sampled at a lower rate Each location tag ID can then identify an object of mterest rather than a position on the surface For example, if the object is a user mterface mput element (e g a command button), then the tag ID of each location tag withm the area of the mput element can dnectly identify the mput element The acceleration measured by the accelerometers m each of the x and y directions is integrated with respect to time to produce an instantaneous velocity and position Smce the starting position of the stroke is not known, only relative positions withm a stroke are calculated Although position mtegration accumulates errors m the sensed acceleration, accelerometers typically have high resolution, and the time duration of a stroke, over which errors accumulate, is short 7. NETPAGE PRINTER DESCRIPTION 7.1 PRINTER MECHANICS The vertically-mounted netpage wallpnnter 601 is shown fully assembled m Figure 11 It prints netpages on Letter/A4 sized media usmg duplexed 8! " Memjet™ prmt engmes 602 and 603, as shown m Figures 12 and 12a It uses a straight paper path with the paper 604 passmg through the duplexed prmt engmes 602 and 603 which prmt both sides of a sheet simultaneously, m full color and with full bleed An integral binding assembly 605 applies a stnp of glue along one edge of each printed sheet, allowmg it to adhere to the previous sheet when pressed against it This creates a final bound document 618 which can range m thickness from one sheet to several hundred sheets The replaceable mk cartridge 627, shown m Figure 13 coupled with the duplexed prmt engmes, has bladders or chambers for storing fixative, adhesive, and cyan, magenta, yellow, black and infrared inks The cartπdge also contams a micro an filter m a base molding The micro an filter interfaces with an an pump 638 mside the prmter via a hose 639 This provides filtered an to the prmtheads to prevent ingress of micro particles mto the Memjet™ prmtheads 350 which might otherwise clog the prmthead nozzles By incorporating the an filter withm the cartridge, the operational life of the filter is effectively linked to the life of the cartπdge The ink cartridge is a fully recyclable product with a capacity for pnntmg and gluing 3000 pages (1500 sheets) Referring to Figure 12, the motorized media pick-up roller assembly 626 pushes the top sheet directly from the media tray past a paper sensor on the first prmt engme 602 mto the duplexed Memjet™ prmthead assembly The two Memjet™ print engmes 602 and 603 are mounted m an opposing -lme sequential configuration along the straight paper path The paper 604 is drawn mto the first prmt engme 602 by integral, powered pick-up rollers 626 The position and size of the paper 604 is sensed and full bleed pnntmg commences Fixative is printed simultaneously to aid drying in the shortest possible time The paper exits the first Memjet™ prmt engme 602 through a set of powered exit spike wheels (aligned along the straight paper path), which act agamst a rubberized roller These spike wheels contact the 'wet' printed surface and continue to feed the sheet 604 mto the second Memjet™ print engme 603 Referring to Figures 12 and 12a, the paper 604 passes from the duplexed prmt engmes 602 and 603 mto the bmder assembly 605 The printed page passes between a powered spike wheel axle 670 with a fibrous support roller and another movable axle with spike wheels and a momentary action glue wheel The movable axle/glue assembly 673 is mounted to a metal support bracket and it is transported forward to mterface with the powered axle 670 via gears by action of a camshaft A separate motor powers this camshaft The glue wheel assembly 673 consists of a partially hollow axle 679 with a rotating coupling for the glue supply hose 641 from the mk cartridge 627 This axle 679 connects to a glue wheel, which absorbs adhesive by capillary - 38 - action through radial holes. A molded housing 682 surrounds the glue wheel, with an opening at the front. Pivoting side moldings and sprung outer doors are attached to the metal bracket and hinge out sideways when the rest of the assembly 673 is thrust forward. This action exposes the glue wheel through the front of the molded housing 682. Tension springs close the assembly and effectively cap the glue wheel during periods of inactivity. As the sheet 604 passes into the glue wheel assembly 673, adhesive is applied to one vertical edge on the front side (apart from the first sheet of a document) as it is transported down into the binding assembly 605. 7.2 PRINTER CONTROLLER ARCHITECTURE The netpage printer controller consists of a controlling processor 750, a factory-installed or field-installed network interface module 625, a radio transceiver (fransceiver controller 753, baseband circuit 754, RF circuit 755, and RF resonators and inductors 756), dual raster image processor (REP) DSPs 757, duplexed print engine controllers 760a and 760b, flash memory 658, and 64MB of DRAM 657, as illustrated in Figure 14. The controlling processor handles communication with the network 19 and with local wireless netpage pens 101, senses the help button 617, controls the user interface LEDs 613-616, and feeds and synchronizes the REP DSPs 757 and print engine controllers 760. It consists of a medium-performance general-purpose microprocessor. The controlling processor 750 communicates with the print engine controllers 760 via a high-speed serial bus 659. The REP DSPs rasterize and compress page descriptions to the netpage printer's compressed page format. Each print engine controller expands, dithers and prints page images to its associated Memjet™ prmthead 350 in real time (i.e. at over 30 pages per minute). The duplexed print engine controllers print both sides of a sheet simultaneously. The master print engine confroller 760a controls the paper transport and monitors ink usage in conjunction with the master QA chip 665 and the ink cartridge QA chip 761. The printer controller's flash memory 658 holds the software for both the processor 750 and the DSPs 757, as well as configuration data. This is copied to main memory 657 at boot time. The processor 750, DSPs 757, and digital transceiver components (transceiver confroller 753 and baseband circuit 754) are integrated in a single confroller ASIC 656. Analog RF components (RF circuit 755 and RF resonators and inductors 756) are provided in a separate RF chip 762. The network interface module 625 is separate, since netpage printers allow the network connection to be factory-selected or field-selected. F ^ memory 658 and the 2x256Mbit (64MB) DRAM 657 is also off-chip. The print engine controllers 760 are provided in separate ASICs. A variety of network interface modules 625 are provided, each providing a netpage network interface 751 and optionally a local computer or network interface 752. Netpage network Internet interfaces include POTS modems, Hybrid Fiber-Coax (HFC) cable modems, ISDN modems, DSL modems, satellite transceivers, current and next- generation cellular telephone transceivers, and wireless local loop (WLL) transceivers. Local interfaces include IEEE 1284 (parallel port), lOBase-T and 100Base-T Ethernet, USB and USB 2.0, EEEE 1394 (Firewire), and various emerging home networking interfaces. If an Internet connection is available on the local network, then the local network interface can be used as the netpage network interface. The radio fransceiver 753 communicates in the unlicensed 900MHz band normally used by cordless telephones, or alternatively in the unlicensed 2.4GHz industrial, scientific and medical (ISM) band, and uses frequency hopping and collision detection to provide interference-free communication. The printer controller optionally incorporates an Infrared Data Association (hrDA) interface for receiving data "squirted" from devices such as netpage cameras. In an alternative embodiment, the printer uses the IrDA interface for short-range communication with suitably configured netpage pens. 7.2.1 RASTERIZATION AND PRINTING Once the main processor 750 has received and verified the document's page layouts and page objects, it runs the appropriate REP software on the DSPs 757. - 39 - The DSPs 757 rastenze each page descnption and compress the rastenzed page image The mam processor stores each compressed page unage m memory The simplest way to load-balance multiple DSPs is to let each DSP rastenze a separate page The DSPs can always be kept busy smce an arbifrary number of rastenzed pages can, m general, be stored m memory This strategy only leads to potentially poor DSP utilization when rastenzmg short documents Watermark regions m the page descnption are rastenzed to a contone-resolution bi-level bitmap which is losslessly compressed to negligible size and which forms part of the compressed page image The infrared (IR) layer of the printed page contams coded netpage tags at a density of about six per mch Each tag encodes the page ED, tag ED, and confrol bits, and the data content of each tag is generated during rasterization and stored in the compressed page image The mam processor 750 passes back-to-back page images to the duplexed prmt engme controllers 760 Each prmt engme confroller 760 stores the compressed page image in its local memory, and starts the page expansion and pnntmg pipeline Page expansion and pnntmg is pipelined because it is unpractical to store an entire 114MB bi-level CMYK+IR page unage m memory 7.2.2 PRINT ENGINE CONTROLLER The page expansion and pnntmg pipeline of the print engme controller 760 consists of a high speed IEEE 1394 senal mterface 659, a standard JPEG decoder 763, a standard Group 4 Fax decoder 764, a custom halftoner/compositor unit 765, a custom tag encoder 766, a lme loader/formatter unit 767, and a custom mterface 768 to the Memjet™ pπnthead 350 The print engme confroller 360 operates m a double buffered manner While one page is loaded mto DRAM 769 via the high speed senal mterface 659, the previously loaded page is read from DRAM 769 and passed through the prmt engme controller pipeline Once the page has finished pnntmg, the page just loaded is printed while another page is loaded The first stage of the pipeline expands (at 763) the JPEG-compressed contone CMYK layer, expands (at 764) the Group 4 Fax-compressed bi-level black layer, and renders (at 766) the bi-level netpage tag layer accordmg to the tag format defined m section 1 2, all m parallel The second stage dithers (at 765) the contone CMYK layer and composites (at 765) the bi-level black layer over the resulting bi-level CMYK layer The resultant bi-level CMYK+IR dot data is buffered and formatted (at 767) for pnntmg on the Memjet™ prmthead 350 via a set of lme buffers Most of these lme buffers are stored m the off-chip DRAM The final stage prints the six channels of bi-level dot data (mcludmg fixative) to the Memjet™ pnnfhead 350 via the pnnthead mterface 768 When several prmt engme controllers 760 are used m unison, such as m a duplexed configuration, they are synchronized via a shared lme sync signal 770 Only one prmt engme 760, selected via the external master/slave pm 771, generates the lme sync signal 770 onto the shared lme The prmt engme controller 760 contams a low-speed processor 772 for synchronizing the page expansion and rendering pipeline, configuring the pπnthead 350 via a low-speed senal bus 773, and controlling the stepper motors 675, 676 In the 8i " versions of the netpage prmter, the two prmt engmes each prints 30 Letter pages per ! πunute along the long dimension of the page (11"), giving a lme rate of 8 8 kHz at 1600 dpi In the 12" versions of the netpage prmter, the two prmt engmes each prints 45 Letter pages per minute along the short dimension of the page (δ'Λ"), giving a lme rate of 102 kHz These lme rates are well withm the operating frequency of the Memjet™ pnnthead, which m the current design exceeds 30 kHz 8 NETPAGE PHOTOGRAPHS Photographs taken with a digital camera can be printed as netpages A user can then obtain a pnstine copy - 40 - of a photo via the ongmal print, even if the ongmal print is severely degraded The photo's digital unage is persistently stored on the netpage network, and the printed photo is a netpage lmked to the digital image A user can archive and organize a collection of photos via a netpage photo manager application They can organize then photo collection mto a set of folders, delete unwanted photos from the collection, and search for photos m the collection A photo user can add photos to then netpage photo collection m several ways They can take photos usmg a normal digital camera and "squirt" the photos to a receptive device which has access to the netpage network The squirting mterface can be a radio mterface (such as Bluetooth) or an infrared mterface (such as IrDA) The receptive device can be a mobile phone, a fixed or mobile netpage prmter, etc They can also take and prmt photos usmg a netpage camera, l e a digital camera containing a netpage prmter and a mobile phone mterface, such as the netpage microprinter A netpage camera typically transmits photos to the netpage network as they are taken It can defer transmission until its local storage fills up, or until the user explicitly requests transmission The netpage system can pre-allocate page IDs to netpage cameras on request, to allow them to prmt netpage photos while off-line A photo user can grant other users (such as family members) access to particular folders m then photo collection Users can thus easily share photos without having to get together and swap negatives or prints This may be particularly convenient when the photo user is fravellmg Even if usmg a netpage camera, the photo user may choose to defer printing of photos while fravellmg, and mstead retneve and print the photos on returning home, e g m the form of printed pages suitable for inclusion m a normal photo album 8.1 APPLICATION DRAWING NOTATION Each application user mterface flow is illustrated as a collection of documents lmked by command arrows A command arrow indicates that the target document is printed as a result of the user pressmg the correspondmg command button on the source page Some command arrows are labelled with multiple commands separated by slashes (7's), mdicatmg that any one of the specified commands causes the target document to be printed Although multiple commands may label the same command arrow, they typically have different side-effects In application terms, it is important to distinguish between netpage documents and netpage forms Documents contain printed mformation, as well as command buttons which can be pressed by the user to request further mformation or some other action Forms, m addition to behaving like normal documents, also contain mput fields which can be filled m by the user They provide the system with a data mput mechanism It is also useful to distinguish between documents which contain genenc mformation and documents which contain mformation specific to a particular interaction between the user and an application Genenc documents may be pre-pnnted publications such as magazmes sold at news stands or advertismg posters encountered m public places Forms may also be pre-pnnted, mcludmg, for example, subscnption forms encountered m pre-pnnted publications They may, of course, also be generated on-the-fly by a netpage prmter m response to user requests User-specific documents and forms are normally generated on the fly by a netpage prmter m response to user requests Figure 48 shows a genenc document 990, a genenc form 991, a user- specific document 992, and a user-specific form 993 Netpages which participate m a user mterface flow are further descnbed by abstract page layouts A page layout may contain vaπous lands of elements, each of which has a umque style to differentiate it from the others As shown m Figure 49, these mclude fixed mformation 994, vanable mformation 995, mput fields 996, command buttons 997, and draggable commands 998 When a user mterface flow is broken up mto multiple diagrams, any document which is duplicated is shown with dashed outlines m all but the mam diagram which defines it - 41 - 8.2 PHOTO COLLECTION OBJECT MODEL With reference to the photo collection class diagram shown in Figure 50, the photo manager 400 manages photo collections on behalf of a number of users. Each photo user 402 is a netpage user 800 (Figure 21), and the details of the photo user derive, by default, from the details of the coπesponding netpage user. A netpage user may have any number of cameras 401, each of which has an ED by which it identifies itself to the netpage system in much the same way that a netpage pen does. A camera, like a pen, is associated with only one netpage user, allowing the system to uniquely associate any input from a camera with a single user. Each photo user has a collection 407 of photos, optionally organized 404 into a set of named folders 405. Each folder has an optional access list 403, indicating which other photo users are granted access to view the photos in the folder. With reference to the photo class diagram shown in Figure 51, each photo 408 in the photo collection has a caption, a capture date and time, and a capture location (e.g. if available from a GPS receiver in the camera). Each photo has a photographer 415. Each photo has a full-size image 417,413 and a corresponding thumbnail image 416,413. Each photo records a set of camera settings 414, including focus, zoom, exposure, whether the flash was used, and the type and model of the camera. Actual camera settings are camera-specific. A photo may have an associated audio annotation 411, if captured by the camera, and a text annotation 410. If the photo was captured and printed by a camera which applied an artistic effect to the photo, then the artistic effect 409 is recorded so that the photo can be reproduced with or without the effect. If the photo was squirted from a camera, then it is associated with a squirt group 412 which contains all the photos which were squirted as a group. This provides a useful unit of organization when presenting the photo collection to the user. 8.3 PHOTO COLLECTION USER INTERFACE 8.3.1 Netpage Camera Photo Capture When a user takes a photo using a netpage camera, the camera automatically transmits the photo to the netpage system. Since the camera is uniquely associated with a particular netpage user, the photo manager automatically adds the photo to the user's photo collection. As described earlier, the camera may transmit the photo to the netpage system as soon as it is taken, or it may defer transmission until a more opportune time. 8.3.2 Photo Squirting When a user squirts a collection of photos to a netpage printer, the printer sends the photos to the photo manager. If the camera is known to the netpage system, then the camera manager adds the photos to the corresponding user's photo collection. If the camera is not known, then the camera manager produces an Add Squirted Photos form 418 (Figure 55) which allows the user to provide their identity by pressing the <add photos> button. The page shows the first and last photo in the squirt group. The photo manager optionally requires the user to sign the form to allow their identity to be verified. The photo squirting user interface flow is illustrated in Figure 52. 8.3.3 Photo Browsing The Photo Manager Menu form 420 (Figure 56) provides a <photo history> button giving the user access to their photo collection presented by date, and a <photo folders> button giving the user access to their photo collection via their named photo folders. The photo manager optionally requires the user to sign the form to allow their identity to be verified. The user obtains the photo manager menu via the netpage directory or a previously created bookmark. The photo manager menu also provides a <photo albums> button, giving the user access to their photo albums. When presented by date, the photo collection is organized into a hierarchy of squirt groups, days, weeks, months and years. Rather than presenting a strict hierarchy, however, the top-level history list also includes recent squirt - 42 - groups, days, weeks and months If a group would contain only one subordinate group,then only one group is presented For example, if a particular week contams only a smgle squirt group, then the week is presented as directly containing the corresponding photo list The <photo hιstory> button on the photo manager menu produces a Photo History List form 421 (Figure 57) Each history list form shows a list of date or date range entπes, and each date acts as a hyperlmk to a more detailed history list or photo list Multiple entπes can be selected via thenr selection checkboxes and subsequently copied to a folder via the <coρy selected> button, or printed as a set of thumbnails via the <pnnt selected> button A termmal date hyperlink produces a Photo List form 419 (Figure 58) Each photo list form shows the thumbnail of each photo m the list, together with its caption, capture date and time, and capture location Multiple entries can be selected via then selection checkboxes and subsequently copied to a folder via the <copy selected> button, printed as a set of thumbnails via the <pnnt selected> button, or deleted via the <delete selected> button Each entry has a <pπnt> button and a <custom> button, both descnbed below The <photo folders> button on the photo manager menu produces a Photo Folders form 422 (Figure 59) The photo folders form shows a list of the user's named folder entnes, and each folder name acts as a hyperlink to a Photo Folder form 423 (Figure 61) The photo folder form shows the thumbnail of each photo m the folder, together with its caption, capture date and time, and capture location Multiple entnes can be selected via then selection checkboxes and subsequently moved to another folder via the <move selected> button, copied to another folder via the <copy selected> button, printed as a set of thumbnails via the <pnnt selected> button, or deleted via the <delete selected> button Each entry has a <pnnt> button and a <custom> button, both descnbed below The caption fields on the photo list and photo folder forms are text entry fields which allow the user to provide captions where none are present or to change captions as desired After entering a number of captions, the user presses the <update captions> button to update the photos' captions A photo must be deleted from both the photo history list and any folders in which it appears to become fully inaccessible via the photo manager It still remains accessible, however, via any netpage prmt of the photo The <copy selected> (or <move selected>) button on the photo history h ^ t, photo list and photo folder pages produces a Copy (or Move) to Photo Folder form 424 (Figure 60), containing a 1 ..t of the user's named photo folders, each with a <copy to> (or <move to>) button The form also contams a <copy to new> (or <move to new>) button together with a text field allowmg the user to name and select a new folder as the destination for the copy (or move) The photo browsmg user mterface flow is illustrated m Figure 53 8.3.4 Photo Printing The <pπnt selected> button on a photo history list, photo list or photo folder form produces a Photo Thumbnails page 425 (Figure 62), showing an anay of thumbnails of the designated photos Each thumbnail acts as a hyperlmk which produces a 12 8" (l e full page) prmt of the photo Each photo entry on a photo list or photo folder form has an associated <pπnt> button which produces a 12x8" (I e full-page) prmt of the photo Each entry also has a <custom> button which produces the Custom Photo Print form 427 (Figure 63) which allows the user to specify custom prmt options The custom prmt form shows the thumbnail, caption, capture date and time, and capture location of the selected photo The user can specify the number of copies of the photo to be printed, and the size od the photo Sizes mclude 6x4", 12x8" (1 e full page), and vaπous multi-page poster sizes The <pπnt> button produces the requested printed copies of the photo The photo pnntmg user mterface flow is illustrated m Figure 54 9 PHOTO ALBUM COMPOSITION AND USE The netpage system, then, provides the facility for enablmg the creation and use of a photo album, allowmg - 43 - a user to collect, organize and pnnt as desned pages from his or her album, along with other associated mformation such as annotations and other relevant data Each printed netpage or netpage document used m the method of the mvention, such as an album list or a page from a user's photo album, is a physical representation of what is referred to herein as a "photo album form", containing as appropnate the mteractive elements (hyperlinks and form fields) 9.1 PHOTO ALBUM COMPOSITION USING THE NETPAGE SYSTEM Usmg the system of the mvention, the netpage photo manager can be employed by a user to compose and pnnt pages of photos smtable for mclusion m a photo album, such as a cumulative family album Composed album pages can also be shared onlme with other netpage users The composer can draw on the user's photo collection which is managed by the photo manager The system also mcludes a tool for automatically laying out album pages 9.2 PHOTO ALBUM OBJECT MODEL The netpage photo manager 400 (Figure 50) manages photo collections 407 and photo albums on behalf of a number of photo users Each photo user 402 has one or more named photo albums 500 The class diagram shown m Figure 64 shows the system of the mvention represented by a set of object classes connected by the relationships between them At the heart of the system is of course the photo album 500 Each photo album consists of a set of album pages 502, each of which is optionally named Each album page 502 consists of a set of placed photos 504 and a set of hand annotations 505, and each page may appear m more than one album Each placed photo has an optional size, its default size if no optional size is specified denvmg from the ongmal photo 408 (I e typically 6x4" or 4x6") Each photo has an optional crop path, which is specified by the user The hand- drawn or handwritten annotations optionally applied to each photo compnse digital ink 873 (Figure 33), which may be colored and textured, as selected by the user from a palette on a netpage before drawing or wnting the annotation Each album page 502 has a background texture which is rendered behind the photos and annotations on the page Each album 500 and album page 502 may be provided with an access list 403 (Figure 50), which indicates which other users are granted access to view the album or the particular album page Each album page has a set of photo options 503, mdicatmg optional graphics, image effects and labels applied to the photos on the page (see Figure 65) The Photo Option class diagram of Figure 66 illustrates the vaπous different options selectable by the user for each photograph Graphic options 508 mclude photo borders 511 and corners 513 and drop shadows 512 Image options 509 mclude black & white conversion 514 of the photo image Label options 510 mclude the photo caption 515, the capture date 516, the capture time 517, and the capture location 518 By way of example, the graphic photo options are illustrated m Figure 66 9.3 PHOTO ALBUM USER INTERFACE 9.3.1 Album Browsing The Photo Manager Menu form 420 (Figure 56) provides a <photo albums> button which gives the user access to then photo albums The user obtains the Photo Manager menu via the netpage directory or a previously created bookmark Checking the <photo albums> button on the Photo Manager menu produces a Photo Album List form 524 (Figure 69), which shows a list of existing photo album names alongside the number of pages m the correspondmg album Multiple entnes can be selected via then selection checkboxes shown on the left of the form, and can be subsequently deleted via the <delete selected> button A new album can be named and created by checking the <create album> button To select one or more particular albums, the user checks the relevant selection checkboxes, and then places the netpage pen on a selected album name to access the album Each album name therefore acts as a hyperlink to a Photo Album form 525 (Figure 70) The <create album> button similarly produces a Photo Album form 525 for the new album - 44 - The Photo Album form 525 of Figure 70 presents a list of numbered and optionally named album pages which constitute that particular album Multiple entnes can be selected via thenr selection checkboxes and subsequently copied to another album via the <copy selected> button, moved to another album via the <move selected> button, and deleted via the <delete selected> button A new page can be named and created via the <msert portrait page> and <msert landscape page> buttons The new page is inserted before the first selected page, or, if no page is selected, at the end of the album Each page number and page name acts as a hyperlink to a Album Page Composition form 526 (Figure 72) The <msert page> buttons similarly produce an album page composition form for the new album page m the selected onentation The <copy selected> (or <move selected>) button on the photo album form produces a Copy/Move Page to Photo Album form 527 (Figure 71), containing a list of the user's named photo albums, each with a <copy to> (or <move to>) button The form also contams a <copy to new> (or <move to new>) button together with a text field allowmg the user to name and select a new album as the destmation for the album page copy (or move) The photo album browsmg user mterface flow shown m Figure 67 illustrates graphically the steps descnbed above 9.3.2 ALBUM PAGE COMPOSITION The Album Page Composition form 526 (Figure 72) contams a representation of the layout of the coπespondrng album page Each placed photo and each hand-drawn or hand-wntten annotation is shown with corner handles By draw/dragging on a handle with the pen, the user can change the size of the coπespondmg photo or annotation The aspect ratio of the photo or annotation is always preserved By draw/dragging on a non-handle area of a photo or annotation, the user can change the position of the photo or annotation This is analagous to dragging and resizing photo images by mouse-controlled cursor on a standard computer display When the user draw/drags with the marking mb of the netpage Pen, the page is not immediately updated Instead, once the user has made all the desned position and size changes, he or she presses the <update> button to obtain an updated version of the page When the user draw/drags with the non-marking mb, the page is immediately updated when the pen tip is lifted from the page surface If the album page bemg composed has a landscape aspect ratio, then the composition page shows the album page with a landscape aspect ratio The user places a photo m the composition by first selecting a photograph For example, a photo may be selected from a user's photogaph folder, and access may be granted to other system users by way of an authorization protocol, such as by signature recognition Alternatively a user may select a photo by circumscnption on any page showing a photo from then photo collection, and then draw/drag from the <paste> draw/drag control to the desned target position m the composition The Page Composition Form is immediately updated The user adds an annotation to the composition by simply drawing or wπting with the netpage pen marking mb m a chosen place m the composition The page is not immediately updated, but the next time the page is updated, the annotation is shown with handles as descnbed above, allowmg the annotation to be re-positioned and re-sized So long as every drawn stroke begms m an interstitial area of the composition, it is not mterpreted by the system as a draw/drag command The <edιt> confrol on the Page Composition form 526 allows the user to select a photo m the composition for editing, by draw/dragging from the <edιt button to the particular photograph This produces an Edit Photo form 528 (Figure 73), showing the entire photo image and its current crop region For convenience, the area of the photo outside the crop region is pnnted with reduced intensity To crop the photo image, the user draws a new crop region and presses the <crop> button, and the page is then immediately updated to show the new crop region To discard the current crop region, the user presses the <uncrop> button, and again, the page is immediately updated After changing the current - 45 - crop region, the user obtains an updated album page composition by pressmg the <re-compose> button The <delete> draw/drag control on the Page Composition Form allows the user to draw/drag to select a photo m the composition for deletion The <to front> and <to back> draw/drag control allow the user to select a photo to be moved to the front or to the back of the composition, respectively A markmg draw/drag produces no immediately effect, whilst a non-marking draw/drag immediately produces an updated page The <zoom m> and <zoom out draw/drag controls allow the user to select a region to zoom mto or zoom out to, respectively This immediately produces an updated Page Composition Form showmg the zoomed view of the composition When the user presses the <no zoom> button, an updated page is immediately produced with the entire composition shown When the user presses the <gnd on> button (shown as "GRID" m Figure 72), an updated page is produced showmg a gnd m the background of the composition Subsequent positioning and re-sizing operations snap to the visible gnd (le to the nearest gπd lines/intersections The button is replaced with a <gnd off> button on the updated page, and when the user presses this button, an updated Page Composition Form is produced showmg no gnd m the background of the composition Subsequent operations, then, do not snap to a gnd When the user presses the <auto-arrange> button, the system automatically re-positions the photos and annotations in the composition according to prescnbed cntena to achieve a balanced distinbution which respects minimum separations between elements and between elements and the border of the page If the composition has a frame (see below), then the arrangement also respects separation from the frame When the user presses the <to text> button, the system automatically converts any hand-wπtten annotations to text, and produces an updated composition page The user can then fine-tune the positioning and size of the vanous annotations m the usual way via the annotation handles The <hst frames> button produces one or more pages containing a list of frames available for framing the composition Frames can be synthetic or can be based on photos of actual picture frames The user adds a frame to the composition by selection the desned frame, by cncumscnption on the printed frame list, and pasting it mto the composition usmg the <paste> draw/drag control The frame list contams a blank frame which the user can select and paste to remove any frame from the composition The Page Composition form is updated to show the pasted frame The <hst textures> button produces one or more pages containing a list of textures available for forming the background of the composition Textures can be synthetic or can be based on photographs, and the user adds a texture to the composition by selection the desned texture, by cncumscnption on the texture list page, and pasting it mto the composition usmg the <paste> draw/drag confrol The texture list contams a blank texture which the user can select and paste to remove any texture from the composition The Page Composition Form is updated to show the updated background texture The <ρnnt album page> button produces the final rendition of the album page 530, as shown m Figure 74, with a portrait or landscape aspect ratio as appropnate, suitable for immediate insertion mto a physical photo album An odd-numbered album page is printed with its even-numbered successor on the other side, and an even-numbered album page is printed with its odd-numbered predecessor on the other size Each photo on the album page 530 acts as a hyperlmk to a full-page pnnt of the photo The user can also annotate the final album page usmg the netpage pen, and these annotations are captured by the netpage system m the usual way (l e ultimately as digital ink stored on a page server) However, such annotations do not make then way mto the album page composition The Page Composition form also contams a set of checkboxes for the vanous photo options, mcludmg the graphic, image and label options Checked options take effect when the composition page is next updated, or when the - 46 - final album page is printed. Multiple options can be selected, and selected labels are automatically positioned below the corresponding photograph. Graphic and image options are deselected by selecting the "plain" option, whilst label options are deselected by selecting the "no label" option. The album page composition user interface flow shown in Figure 68 illustrates the various steps described above. CONCLUSION The present invention has been described with reference to a preferred embodiment and number of specific alternative embodiments. However, it will be appreciated by those skilled in the relevant fields that a number of other embodiments, differing from those specifically described, will also fall within the spirit and scope of the present invention. Accordingly, it will be understood that the invention is not intended to be limited to the specific embodiments described in the present specification, including documents incorporated by cross-reference as appropriate. The scope of the invention is only limited by the attached claims.

Claims: - 47 - C LAI MS 1 A method of enablmg the creation and use of a photo album, the method mcludmg the steps of providing a photo album user with at least one photo album form printed on a surface, the photo album form contammg information relating to a photo album activity and mcludmg coded data mdicative of an identify of the photo album form and of at least one reference pomt of the photo album form, receivmg, m a computer system, mdicatmg data from a sensmg device operated by said user, said mdicatmg data regardmg the identify of the photo album form and a position of the sensmg device relative to the photo album form, the sensmg device, when placed m an operative position relative to the photo album form, sensmg the mdicatmg data usmg at least some of the coded data, and identifying m the computer system and from the mdicatmg data, at least one parameter relating to the photo album activity 2 The method of claim 1 m which said at least one parameter relating to the photo album activity is associated with at least one zone of the photo album form, and m which the method mcludes identifying, m the computer system and from the zone relative to which the sensmg device is located, said at least one parameter 3 The method of claim 2 which mcludes the steps of receivmg, m the computer system, data regardmg movement of the sensmg device relative to the photo album form, the sensmg device sensmg its movement relative to the photo album form, usmg at least some of the coded data, and identifying, m the computer system and from said movement bemg at least partially withm said at least one zone, said at least one parameter of the photo album activify 4 A method of enablmg the creation and use of a photo album, the method mcludmg the steps of providing a user with at least one photo album form printed on a surface, the photo album form contammg mformation relating to a photo album activity and mcludmg coded data mdicative of at least one parameter of the photo album activify, receivmg, m a computer system, data from a sensmg device operated by said user regardmg said at least one parameter and regardmg movement of the sensmg device relative to the photo album form, the sensmg device, when moved relative to the photo album form, sensmg the data regardmg said at least one parameter usmg at least some of the coded data and generating the data regardmg its own movement relative to the photo album form, and interpreting, m the computer system, said movement of the sensmg device as it relates to said at least one parameter 5 The method of claim 1 or claim 4, m which the parameter is an action parameter of the photo album activity, the method mcludmg effecting, m the computer system, an operation m respect of the action parameter 6 The method of claim 5, m which the action parameter of the photo album activify is selected from the group compnsing creating a photo album, selecting an existing photo album, deselecting an existing photo album, selecting an existing photo album page, deselecting an existing photo album page, - 48 - mserting a page mto a photo album, moving a photo album page, copymg a photo album page, zooming a view of a photo album page, applying a background gnd to a view of a photo album page, updating a view of a photo album page, inserting a photograph on a photo album page, editing the appearance of a photograph on a photo album page, arranging at least one photograph on a photo album page, deleting a photograph from a photo album page, converting handwntten annotation to electronic text, listing available photo frames, listing available photo album page background textures, pnntmg a photo album page, and editing an individual photograph 7 The method of claim 1 or claim 4 m which the parameter is an option parameter of the photo album activity, the method mcludmg identifymg, m the computer system, that the user has entered a hand-drawn mark by means of a sensmg device and effecting, m the computer system, an operation associated with the option parameter 8 The method of claim 7 m which the option parameter is associated with at least one of selecting a photo album, selecting a photo album page, a graphic applicable to a photograph, and a caption associated with a photograph 9 The method of claim 1 or claim 4 m which the parameter is a text parameter of the photo album activify, the method mcludmg identifymg, m the computer system, that the user has entered handwntten text data by means of the sensmg device and effecting, m the computer system, an operation associated with the text parameter 10 The method of claim 9 which mcludes converting, m the computer system, the handwntten text data to computer text 11 The method of claim 9 m which the text parameter is associated with at least one of a photo album name, a photo album page name, and an annotation associated with a photograph 12 The method of claim 1 or claim 4 m which the parameter is an authorization parameter of the photo album activity, the method mcludmg identifymg, m the computer system, that the user has entered a handwntten signature by means of the sensmg device and effecting, m the computer system, an operation associated with the authorization parameter 13 The method of claim 12 which mcludes venfymg, m the computer system, that the signature as that of the user 14 The method of claim 13 m which the authorization parameter is associated with accessing a selected photograph 15 The method of claim 1 or claim 4 m which the parameter is a graphical parameter of the photo album activity, the method mcludmg identifymg, in the computer system, that the user has entered hand-drawn graphical - 49 - lnformation by means of the sensmg device and effecting, m the computer system, an operation associated with the graphical parameter 16 The method of claim 15 m which the graphical parameter is associated with an annotation associated with a photograph 1 The method of claim 1 or claim 4 m which at least one of the one or more photo album forms contams information relating to at least one of an identify of the photo album user, the date of the photo album activity, the time of the photo album activity, a photo album name, a photo album page count, a photo album page number, a photograph image, and a printed photo album page 18 The method of claim 1 or claim 4, the surface bemg a paper page, the method mcludmg pnntmg the page on demand 19 The method of claim 18 which mcludes pnntmg the page and, at the same time that the page is printed, printing the coded data on the page 20 The method of claim 19 which mcludes pnntmg the coded data to be substantially invisible m the visible spectrum 21 The method of claim 1 or claim 4 which mcludes retaining a retnevable record of each photo album form generated, the photo album form bemg retnevable usmg its identify as contained m its coded data 22 The method of claim 1 or claim 4 m which the photo album form compnses at least one printed photo album page 23 The method of claim 1 or claim 4 m which the sensmg device contams an identification means which imparts a umque identify to the sensmg device and identifies it as bemg associated with a particular user and m which the method mcludes monitoring, m the computer system, said identify 24 The method of claim 1 or claim 4 which mcludes providing all required information relating to the photo album activity on the at least one photo album form, to eliminate the need for a separate display device 25 The method of claim 1 or claim 4 m which the photo album form is provided on multiple pages and m which the method mcludes binding the pages 26 A system for enablmg the creation and use of a photo album, the system mcludmg at least one photo album form printed on a surface, the photo album form contammg information relating to a photo album activify and mcludmg coded data mdicative of an identity of the photo album form and of at least one reference pomt of the photo album form, and a computer system for receivmg mdicatmg data from a sensmg device operated by a user mvolved m the photo album activity, said mdicatmg data regardmg the identity of the photo album form and a position of the sensmg device relative to the photo album form, the sensmg device, when placed m an operative position relative to the photo album form, sensmg the mdicatmg data usmg at least some of the coded data, said computer system mcludmg means for identifymg, from the mdicatmg data, at least one parameter relating to the photo album activify 27 The system of claim 26 m which said at least one parameter relating to the photo album activity is associated with at least one zone of the photo album form - 50 - 28 The system of claim 26 mcludmg the sensmg device, the sensmg device sensmg its movement relative to the photo album form, usmg at least some of the coded data 29 A system for enablmg the creation and use of a photo album, the system mcludmg at least one photo album form printed on a surface, the photo album form contammg information relating to a photo album activify and mcludmg coded data mdicative of at least one parameter of the photo album activity, and a computer system for receivmg data from a sensmg device operated by the user mvolved m the photo album activity, said data regardmg movement of the sensmg device relative to the photo album form, and for mterpretmg said movement of the sensmg device as it relates to said at least one parameter, the sensmg device, when moved relative to the photo album form, sensmg the data regarding said at least one parameter usmg at least some of the coded data, and generating the data regardmg its own movement relative to the photo album form 30 The system of claim 29 m which said at least one parameter relating to the photo album activify is associated with at least one zone of the photo album form 31 The system of claim 30 mcludmg the sensmg device 32 The system of claim 26 or claim 29 m which said at least one parameter of the photo album activify is selected from the group compnsmg an action parameter of the photo album activify, an option parameter of the photo album activity, a text parameter of the photo album activity, an authorization parameter of the photo album activity, and a graphical parameter of the photo album activify 33 The system of claim 32 m which the action parameter of the photo album activify is selected from the group compnsmg creating a photo album, selecting an existing photo album, deselecting an existing photo album, selecting an existing photo album page, deselecting an existing photo album page, inserting a page mto a photo album, movmg a photo album page, copying a photo album page, zooming a view of a photo album page, applying a background gπd to a view of a photo album page, updating a view of a photo album page, inserting a photograph on a photo album page, editing the appearance of a photograph on a photo album page, arranging at least one photograph on a photo album page, deleting a photograph from a photo album page, converting handwntten annotation to electronic text, listing available photo frames, listing available photo album page background textures, pnntmg a photo album page, and editing an individual photograph 34 The system of claim 32 m which the option parameter is associated with at least one of selecting a photo album, selecting a photo album page, - 51 - a graphic applicable to a photograph, and a caption associated with a photograph 35 The system of claim 32 m which the text parameter is associated with at least one of a photo album name, a photo album page name, and an annotation associated with a photograph 36 The system of claun 32 m which the authorization parameter is associated with accessmg a selected photograph 37 The system of claim 32 m which the graphical parameter is associated with an annotation associated with a photograph 38 The system of claim 26 or claun 29 m which the sensmg device mcludes a markmg mb 39 The system of claim 26 or claun 29 m which the sensmg device contams an identification means which imparts a unique identify to the sensmg device and identifies it as bemg associated with a particular user 40 The system of claun 26 or claim 29 m which the surface is a printed paper page, and m which the system mcludes a prmter for printing the photo album form on the paper page on demand 41 The system of claim 40 m which the prmter prints the coded data at the same time as pnntmg the photo album form on the paper page 42 The system of claun 26 or claim 29 m which the coded data is substantially invisible m the visible spectrum 43 The system of claim 26 or claim 29 m which the photo album form compnses at least one printed photo album page 44 The system of claim 26 or claim 29 which mcludes a database for keepmg a retnevable record of each photo album form generated, each photo album form bemg retnevable by usmg its identity as mcluded m its coded data 45 The system of claim 40 m which, to cater for a photo album form printed on multiple pages, the prmter mcludes a binding means for binding the pages

Inventors: LAPSTUN PAUL, LAPSTUN, PAUL
Applicants: LAPSTUN PAUL, SILVERBROOK KIA, SILVERBROOK RES PTY LTD, LAPSTUN, PAUL, SILVERBROOK RESEARCH PTY LTD, SILVERBROOK, KIA
Application year: 2000
Main classification: G06K9
IPC codes: B41J2, B41J5, B41J13, B41J21, B41J29, B42C9, B42C19, B42D15, B65H29, B65H37, G06F3, G06F13, G06F17, G06F21, G06K9, G06K17, G06K19, G06Q10, G06Q30, G06Q50, G06T1, G06T11, G08C17, H04L9, H04N1