ENCODING SYSTEM AND METHOD FOR SCROLLING ENCODED MPEG STILLS IN AN INTERACTIVE TELEVISION APPLICATION

Abstract: A system and method for scrolling in a picture which is larger than MPEG standard in length or width or both in a video system, such as an interactive television system. In the preferred embodiment, the interactive television system comprises a video delivery system for providing video content, and at least one subscriber television including a display screen, wherein the subscriber television is coupled to the video delivery system. The video delivery system provides the compressed picture. The compressed picture has a length and/or a width which is larger than MPEG standard or alternatively is larger than the desirable viewing size. The compressed picture is subdivided into slices and possibly groups of slices such that the image may be smoothly scrolled. The subscriber television receives the compressed picture and operates to scroll in the compressed picture as desired by the user. The scrolling operation preferably includes providing additional compressed picture slices for decoding in place of slices in a previously viewed image of a portion of the compressed picture. The subscriber television then decodes the resulting picture and displays a next portion of the scrolled picture.

Description: Title: Encoding System and Method for Scrolling Encoded MPEG Stills in an Interactive Television Application BACKGROUND OF THE INVENTION Field of the Invention The present invention is related to interactive video delivery mediums such as mteractive television, and more particularly to a system and method for generating and scrolling pictures in an mteractive television application Description of the Related Art Interactive television is an mteractive audio/video delivery medium which provides broadcast audiovisual content to a number of subscribers Interactive television provides broadcast video and audio to users and also provides a return path for the user to interact with the content, e g , to make selections or order desired products, etc To provide content with maximum bandwidth efficiency, interactive television systems may compress their content with an audio/video or image compression technique The system at the subscriber's location must then be able to decompress the content for local display or replay The Internet is a world wide collection of inter-connected networks In the last several years, the Internet has been growing at an exponential rate The major attribute that these inter-connected networks share is use of the Transmission Control Protocol Internet Protocol (TCP/IP) communications protocol Several different protocols are used for making information available on the Internet Among these are the text-only, hierarchical Gopher protocol and the Hyper Text Transfer Protocol (HTTP) used on the hypertext, multimedia World Wide Web (WWW or Web) In many applications it is desirable to display still pictures or images on an mteractive television system Examples include the display of advertising pictures, electronic program guides or other content, for an mteractive television application Another example is an interactive television system used for Internet activities, such as web browsmg The use of an Internet capable television system for web browsing is often generally referred to as web TV The transmission and display of still images or pictures, such as Internet files, through an interactive television system is hampered by the need to compress the large size and quantity of files required to be transmitted to the subscnber Compression becomes complicated by the consideration that it may be desirable to provide still images or pictures with different, unique sizes Therefore, the need exists to be able to compress Internet files m such a way that they can be decoded m a standard manner Also, m many cases it is desirable to provide still images or pictures to a television system which are larger than the viewing size of the television For example, Internet web pages are typically larger than the viewing screen of a computer display Thus, to provide or simulate web browsmg capabilities in an interactive television environment, it is necessary or desirable to be able to provide still pictures to the television which are larger than the viewing area of the television This is complicated by the fact that many compression standards require a standard, fixed image size, for compression and decompression purposes When pictures are provided to a television which are larger than the viewing size of the television, it is necessary to provide the user with the capability to scroll down and/or across the display screen, much like the user can scroll through an image on a computer screen. However, providmg a user m an mteractive television application with the ability to scroll through an unage is complicated by the video compression used in sendmg still pictures to the television. Therefore, a system and method is desired which enables a user to scroll through pictures m an mteractive television application. MPEG Background Background on MPEG compression is deemed appropnate. A common compression technique used m an interactive television environment is referred to as MPEG (Moving Pictures Experts Group) MPEG compression is a set of methods for compression and decompression of full motion video images which uses mterframe and mtraframe compression techmques MPEG compression uses both motion compensation and discrete cosine transform (DCT) processes, among others, and can yield compression ratios of more than 200:1. The two predominant MPEG standards are referred to as MPEG-1 and MPEG-2. The MPEG-1 standard generally concerns inter-field data reduction usmg block-based motion compensation prediction (MCP), which generally uses temporal differential pulse code modulation (DPCM) The MPEG-2 standard is similar to the MPEG-1 standard, but includes extensions to cover a wider range of applications, including mterlaced digital video such as high definition television (HDTV). An MPEG stream mcludes three types of pictures, referred to as the Intra (I) frame, the Predicted (P) frame, and the Bi-directional Interpolated (B) frame. The I or Intra frames contam the video data for the entire frame of video and are typically placed every 10 to 15 frames. Intra frames provide entry pomts mto the file for random access, and are generally only moderately compressed. Predicted frames are encoded with reference to a past frame, i.e., a pπor Intra frame or Predicted frame. Thus P frames only include changes relative to pπor I or P frames. In general, Predicted frames receive a fairly high amount of compression and are used as references for future Predicted frames. Thus, both I and P frames are used as references for subsequent frames. Bi-directional pictures mclude the greatest amount of compression and require both a past and a future reference m order to be encoded. Bi-directional frames are never used as references for other frames An MPEG encoder divides respective frames mto a gnd of 16 x 16 pixel squares called macroblocks. The respective frames are divided into macroblocks in order to perform motion estimation/compensation. Each picture is comprised of a plurality of slices. The MPEG standard defines a slice as a contiguous sequence of 2 or more macroblocks (16 x 16 pixel blocks) that begin and end on the same row of macroblocks. A slice begms with a header including a slice start code and information indicating die horizontal and vertical locanon where the slice begms in the picture. Furthermore, header information is provided for m the MPEG standards for each piece of the overall picture. Each macroblock, slice, frame, etc. has its own header containing information about the particular picture piece as well as its placement in the next larger piece of the overall picture. SUMMARY OF THE INVENTION The present mvention comprises a system and method for scrolling a picture which is larger then the allowed size of an MPEG encoded picture m a video system, such as an mteractive television system In the preferred embodiment, the interactive television system compnses a video delivery system for providmg video content, and at least one subscnber television including a display screen, wherem the subscriber television is coupled to the video delivery system According to the present invention, the video delivery system provides or broadcasts a compressed picture The compressed picture is larger, 1 e , wider and/or longer, than a standard MPEG picture The compressed picture comprises a plurality of slices, wherem the plurality of slices are compressed with a slice structure to facilitate scrolling, and wherem the plurality of slices include one or more slices which are mdependently compressed The slices are encoded with a predetermined slice structure and are preferably mdependently compressed to enable scrolling according to the present invention The subscnber television receives the compressed picture or a portion of the compressed picture The subscnber television mitially displays a default portion of the compressed picture, wherem the size of the default portion fits the display area of the television and/or is a standard MPEG size When the user wishes to scroll the image on the screen, the user provides scrolling mput to the subscriber television In response to receiving the scrolling input, the subscriber television provides the appropriate slices which make up the new desired portion of the picture to the decoder The decoder then decodes those slices for viewmg on the display screen of the subscnber television Thus, the user selects the desired portion of the picture to be viewed, and the subscnber television operates to send the appropnate slices which make up the desired portion of the picture to be viewed to the decoder In this manner, the user can scroll through different parts of the picture Also, the subscnber television only provides slices to the decoder which correspond to a display area of a television and/or a standard MPEG size, and then die decoder only receives and decodes pictures of that size In one embodiment, the video delivery system mitially only provides to the subscriber television a portion of an MPEG picture which conesponds to a standard MPEG size Thus, when the subscnber television receives scrolling mput from the user, the subscriber television requests additional slices from the video delivery system This reduces the amount of memory required by the subscriber television decoder or set top box In another embodiment, the video delivery system mitially provides all of the slices corresponding to the entire picture to the subscriber television In this embodiment, the subscriber television selectively provide slices to the decoder, which correspond to a standard size MPEG picture, based on user scrolling input In one embodiment the video delivery system also preferably provides a table indicating the starting pomts of each slice comprising the compressed picture The subscriber television receives the table and provides the user requested slices to the decoder usmg the table locations for each slice The present invention also includes a system and method for creating and encoding a compressed picture which is larger than standard viewmg size, as well as a method for creatmg the conesponding slice starting pomt tables As noted above, the compressed pictures are created with appropnate slice structures to enable compressed slices to replace other slices m a compressed picture as the picture is scrolled on a television display screen BRIEF DESCRIPTION OF THE DRAWINGS A better understanding of the present invention can be obtamed when the following detailed description of the preferred embodiment is considered in conjunction with the following drawings, m which Figures 1 illustrates an interactive television system, Figure 2 illustrates the mteractive television system of Figure 1 which mcludes a remote network that provides programming content, Figure 3 is a block diagram of the mteractive decoder of Figures 1 and 2, Figure 3 A is an alternate embodiment of the mteractive decoder of Figure 3 Figure 4A illustrates a slice structure which allows vertical scrollmg accordmg to the present mvention, Figure 4B illustrates a slice structure including one or more columns of slices which allow for horizontal scrollmg accordmg to the present mvention, Figure 4C illustrates a slice structure similar to Figure 4B mcludmg one or more columns of slices accordmg to the present mvention, wherem both vertical scrollmg and horizontal scrollmg are possible Figure 4C illustrates different horizontal scrollmg positions of the picture, Figure 5 is a flowchart diagram illustrating the creation of a compressed file or picture usmg a predetermined slice structure, Figure 6 is a flowchart diagram illustrating the encodmg step of Figure 5 accordmg to the present invention, Figure 7 is a flowchart diagram illustrating the process of viewing a compressed picture with a subscnber television havmg reduced memory requirements accordmg to the present mvention, Figure 8 is a flowchart diagram illustrating the process of scrollmg m a compressed picture with a subscriber television havmg reduced memory requirements accordmg to the present mvention, Figures 9 is a flowchart diagram illustrating the display routme of Figures 7 and 10 accordmg to the present mvention, Figure 10 is a flowchart diagram illustrating the process of viewmg a compressed picture with a subscnber television havmg sufficient memory to store the entire scrollable picture accordmg to the present mvention, and Figure 11 is a flowchart diagram illustrating d e process of scrollmg m a compressed picture with a subscriber television havmg sufficient memory to store the entire scrollable picture according to the present invention DETAILED DESCRIPTION OF THE EMBODIMENTS The present invention comprises a system and method for scrollmg m a picture which is larger than the allowed size of an MPEG image m a video delivery system The present mvention also allows for scrollmg in a picture which is larger than die viewmg area of a screen, such as a television screen or computer screen In the prefened embodiment, the system and method are compnsed m an interactive television system However, it is noted that the present mvention may be included in any of vanous types of video systems, mcludmg standard television, mteractive television, the Internet, and other types of video or graphics delivery mediums The term "video" as used herem is mtended to include still images, graphics, and live action or motion video Interactive Television System Refemng now to Figure 1, a block diagram of an mteractive television system accordmg to one embodiment of the present invention is shown It is noted that Figure 1 is illustrative only, and other mteractive television system embodiments may be used, as desired As shown, die mteractive television system employs a broadcast center 100 for generating audiovisual content, mcludmg mteractive audiovisual content The broadcast center 100 mcludes an audio / video source 102 for providmg the audiovisual content The audiovisual content may compnse movies, sports, news, sitcoms or other audiovisual programming, as is normally seen on television The audiovisual content preferably compnses still images which may be used for various purposes These still images preferably mclude pages from the Web The audiovisual content may mclude background pictures or images, as well as insert pictures or overlays which are designed to be overlaid on the background picture The Web pages, background pictures and insert pictures may compnse still images or portions of a motion video sequence, as desired Accordmg to the present mvention, the audiovisual content includes MPEG encoded images which are larger than a standard MPEG size The audio / video source 102 may mclude video compression logic for compressmg still video images mto compressed still video images As shown in Figure 2, the audiovisual content may also be supplied by a remote network 170 or a live feed, as desired The broadcast center 100 also mcludes an application server 104 for creatmg and/or generating mteractive application content The mteractive application content compnses application code and data which is designed to be executed by a processor withm a set top box or television to support an mteractive television feature The application server 104 is preferably configured for generatmg or providmg "OpenTV" mteractive applications The application server may also provide "Java" applets or other interactive program content, as desired An Encoder / Multiplexer 106 combmes the mteractive application content widi the audiovisual content to produce an audio- video-mteractive (AVI) signal The Encoder / Multiplexer 106 also synchronizes the mteractive application content with the audiovisual content to ensure that the interactive application content is inserted in the proper position withm the audiovisual content It is noted that certain channels may compnse non-interacnve programming content In other words, certain audiovisual content may not have associated mteractive content The Encoder / Multiplexer 106 preferably multiplexes a plurality of signals, mcludmg AVI signals and optionally non-mteractive signals, togedier for transmission The broadcast center 100 also mcludes an uplink satellite 108 for transmitting the broadcast signal for receipt by end-users or a subsequent distribution link It is noted that Figure 1 illustrates a satellite network example where a satellite is used to transmit the broadcast signal However, it is noted that other transmission metiiods may be used, mcludmg cable distnbution through coaxial cable, fiber optic transmission, microwave transmission or other means The broadcast signal is received from broadcast center 100 via a satellite downlink 120 The broadcast signal is then provided to a plurality of subscnbers As noted above, the broadcast signal mcludes one or more AVI signals on respective channels, and may mclude one or more non-mteractive program signals As shown, each end user or subscriber preferably mcludes a set top box or mteractive decoder 140 as well as a television set 150 The set top box or interactive decoder 140 is coupled to the television set 150 It is noted that the mteractive decoder logic may be compnsed m the television 150 instead of being compnsed as a separate unit 140 Also, the television may comprise a general purpose programmable computer havmg a display screen, or other viewmg device, as desired In die present disclosure, the term "subscriber television" is mtended to include the television set 150 or other viewmg device, such as a computer, LCD (liquid crystal display) screen, etc , and may mclude associated decoder logic for decoding compressed video and/or executmg interactive programs For example, in one embodiment, the subscnber television compnses the television set 150 coupled with the mteractive decoder or set top box 140 The television 150 includes a remote control 152 which facilitates user interaction with the television 150 and or mteractive decoder 140 The user can select desired television channels for viewmg or provide vanous mteractive selections Once a picture has been selected, if the picture has a size larger than a standard MPEG size, the user may use the remote control 152 to scroll vertically and/or horizontally withm the picture as desired, accordmg to usmg the present mvention The signal on the selected television channel is decoded by die mteractive decoder 140 which provides an output to the television set 150 The mteractive decoder 140 preferably executes a real time operating system, such as OpenTV from Thomson Electronics Where the channel bemg viewed compnses an AVI signal, the mteractive decoder 140 also executes an mteractive application program conveyed withm the selected AVI signal to enable an mteractive television feature A return channel 156 interconnects the mteractive decoder 140 to a transaction server 160, which monitors certain selections by the user and responds accordmgly, as desired The return channel 156 preferably utilizes a standard POTS (plam old telephone system) phone lme and associated modems (not shown) for communication O ier return channel options, such as coaxial cable, fiber optic cable, DSL (Digital Subscnber Lme), ATM (Asynchronous Transfer Mode), or others, may be used, as desired The broadcast center 100 provides a plurality of program channels each compnsmg audiovisual content One or more program channels comprise AVI signals mcludmg audiovisual content and associated interactive applications The encoder 106 at the broadcast center 100 is operable to transmit compressed pictures, mcludmg compressed pictures which are larger than a standard MPEG size The encoder 106 encodes pictures which have a nonstandard or larger MPEG size with the necessary slice structure for scrollmg of the pictures The encoder 106 is also operable to transmit slice maps to assist m the scrollmg Therefore, m the preferred embodiment, at least a subset of the AVI signals include compressed pictures which are larger than die standard MPEG size These AVI signals preferably mclude mteractive applications which are executable to scroll through the compressed picture which is larger than die MPEG standard The compressed pictures may be larger than die standard MPEG size either m length or width or both The mteractive application tiius operates to display a selected portion of a picture based on user scrollmg mput The logic and/or software which operates to enable a user to scroll through a respective picture may also reside permanently on the set top box 140, mstead of bemg transferred as an mteractive applet Figure 3 - Interactive Decoder Refemng now to Figure 3, a block diagram illustrating the set top box or mteractive decoder 140 is shown As shown, die mteractive decoder 140 mcludes an mput for receiving a broadcast signal over a channel The broadcast signal preferably compnses a plurality of channels compnsmg programming content, such as movies, sports, television shows, news, advertising, etc At least a subset, I e , one or more, of the program channels compnses an AVI (audio video mteractive) signal which compnses an audiovisual component as well as an mteractive program component as descnbed above The audiovisual component is preferably compressed, preferably MPEG compressed As noted above, the broadcast signal, preferably the mteractive program content, may mclude one or more compressed pictures that are larger than MPEG standard size m either length or width or both The broadcast signal also preferably includes associated slice map information for tiiese pictures The broadcast channel signal is provided to a demultiplexer 302 m the interactive decoder 140 The demultiplexer 302 operates to separate the audio/video component from the interactive component In the preferred embodiment of the mvention, the mteractive component comprises an mteractive application and/or data which is compliant with the OpenTV standard promulgated by Thomson Electronics However, it is noted that other types of mteractive applications may be mcluded m the AVI signal, as desired The demultiplexer 302 provides the audio/video component to an audio/video decodmg block 304 The decoding block 304 operates to decode the compressed audiovisual data stream to produce decompressed data In the preferred embodiment, the broadcast channel transports MPEG-2 compressed data Thus, m die prefened embodiment, the decodmg process block 304 preferably mcludes an MPEG-2 decoder for decompressing or decodmg the encoded data The decoder 304 preferably includes one or more DSPs and one or more associated memones It is noted diat the decoder may compnse various types of logic, mcludmg one or more DSPs, CPUs, or microcontrollers, discrete logic, or combmations thereof The decodmg process block 304 provides an audio/video output which is preferably provided to the television 150 for display When die decodmg block 304 receives compressed slices from the memory, the decoding block 304 decompresses the slices and provides the decompressed slices to the display unit The mteractive decoder 140 mcludes a memory 316, preferably a read only memory (ROM), which stores the mteractive application operating system The operating system is preferably the OpenTV operating system from Thomson Electronics A CPU 314 is coupled to the ROM 316 The mteractive program component which is provided by the output of the demultiplexer 302 is provided to a memory 312, preferably a random access memory (RAM), which stores the mteractive application, I e , the OpenTV application The CPU 314 is coupled to die interactive application RAM 312 Thus, the mteractive application from the AVI signal is stored in the RAM 312, and die CPU 314 can read the application from the RAM 312 and execute the application Thus, die CPU 314 reads the OpenTV operatmg system from the ROM 316, whereby the operatmg system controls the operation of the CPU 314 The CPU 314 also reads the mteractive application from the RAM 312, which was provided with the AVI signal, and executes this mteractive application under control of die OpenTV operatmg system stored m ROM 316 In me embodiment of Figure 3, compressed pictures which are larger than MPEG standard in length or width or both are compnsed m the interactive application Thus, m is embodiment, the compressed pictures which are larger than MPEG standard in length or width or both are mcluded as part of the mteractive application, and not as part of the audiovisual component In this embodiment, the compressed pictures are received by the demultiplexer 302 and then temporarily stored m the RAM 312 In vanous embodiments, either a portion or all of a compressed picture of nonstandard MPEG size is stored m the RAM 312, as described further below Refemng briefly to Figure 3A, in anotiier embodiment, portions of compressed pictures which are larger than standard MPEG size are compnsed m the audio/video portion of the signal In tins embodiment, the audio/video decodmg block mcludes a picture buffer 303 havmg a size conespondmg at least to a standard MPEG size The picture buffer 303 receives and stores the portions of compressed pictures and selectively provides slices to the decoder 304, as discussed further below The mteractive component preferably also mcludes at least one slice map to assist m scrollmg m compressed pictures which are larger than the MPEG standard In other words, die video delivery system preferably provides slice maps with any compressed pictures of nonstandard MPEG size to aid m scrollmg m the compressed picture The RAM 312 mcludes an output coupled to die decoder 304, as shown The CPU 314 controls the output from the RAM 312 to provide MPEG slices to the decoder 304 More specifically, the CPU 314 directs the RAM 312 to provide slices from compressed pictures to the decoder 304 to accomplish scrollmg m compressed pictures larger than MPEG standard size accordmg to the present mvention The CPU 314 preferably executes the interactive application and uses any slice maps stored m the RAM 312 to provide the slices to the decoder 304 in die proper order for scrollmg As discussed further below, scrollmg m a compressed picture larger than MPEG standard size accordmg to the present mvention compnses replacmg one or more slices of the portion of the picture cunently bemg displayed with new slices to display the new portion of die picture which is desired to be viewed More specifically, scrollmg from a first view of the compressed picture to a second view compnses the CPU 314 directing die RAM 312 to provide die new slices of the compressed picture which are part of the second view for decodmg m place of slices from the first view which will no longer be displayed In one embodiment, the CPU 314 provides an output to a graphic on-screen display block 322 The graphic on-screen display block 322 is coupled to provide an output m conjunction witii the audio/video output provided by decoder 304 The graphic on-screen display block 322 organizes data m a format which can be overlaid on top of the audio/video output of die decoder 304 Thus, die CPU 314 executes an mteractive application and generates on-screen graphics which are provided m conjunction with the audio/video stream bemg output from the decoder 140 Thus, for example, if the mteractive application is wntten to cause one or more images or selection options to be displayed or overlaid on top of a television program or still image, the CPU 314 executing die application provides die appropnate output to the graphic on-screen display block 322, and the block 322 causes die respective images or selection buttons to be overlaid on top of and/or displayed with die audio/video output of the decoder 304 The mteractive decoder 140 also includes an mput for receivmg user mput This user mput is provided to an mput of the CPU 314 This user mput may be provided from various devices, preferably from remote control 152 or from buttons on the TV 150 or the mteractive decoder 140 The user mput provided to the CPU 314 enables a user to mteract with die mteractive application For example, the user or viewer may choose a selection or button to order a product or order information, provide answers to a television game show, etc As another example, accordmg to the present mvention, the user may also provide scrolling input to selectively scroll m a vertical and or horizontal fashion m compressed pictures which are larger than MPEG standard size in lengtii or width or both The mteractive decoder 140 also mcludes a modem 324 which provides mformation on die return channel 156 for user interactivity As shown m Figure 3, the CPU 314 is coupled to the modem 324, and e modem 324 is coupled to a return channel output of the mteractive decoder 140 In die embodiment shown m Figure 3, the modem 324 may be used for bi-directional communication As shown m Figure 1, the return channel 156 preferably couples to a transaction server 160 Thus, if the user selects an option to order mformation, or purchase a product, die transaction server 160 receives this order and processes the order for fulfillment Also, if die user answers questions m a game show, the answers are provided on the return channel 156 to the transaction server 160 Figure 3A - Interactive Decoder Alternate Embodiment Referring now to Figure 3A, as noted above, m an alternate embodiment, die compressed pictures which are larger than MPEG standard size are comprised m the audiovisual content portion of die bitstream In this embodiment, the set top box or mteractive decoder 140 mcludes a picture buffer or memory 303 coupled between the demultiplexer 302 and the decoder 304 The picture buffer 303 may also be compnsed m the decoder 304, as desired The picture buffer 303 is operable to store portions of a compressed picture, or all of a compressed picture, to facilitate providmg slices to the decoder 304 m order to accomplish scrollmg m a compressed picture which is larger than MPEG standard size accordmg to the present mvention In other words, d e picture buffer 303 facilitates providmg new slices from a second portion of the compressed picture desired to be viewed to replace slices from a first portion of the compressed picture to accomplish scrollmg In tins embodiment, the buffer 303 and RAM 312 may optionally exchange mformation as shown This provides for the buffer 303 to transfer slices to and from the RAM 312 if storage or background manipulation is desired In otiier words, should the buffer 303 receive more mput from the demultiplexer 302 than the buffer 303 can store, 1 e , the nonstandard MPEG picture is larger than the picture buffer 303, the buffer 303 may transfer slices or other data to the RAM 312 for storage and later retneval Alternatively, as discussed further below, the picture buffer 303 only stores a portion of the compressed picture, and the decoder 140 requests additional slices from the video display system based on received scrollmg mput In this embodiment, the CPU 314 also provides an output to die buffer 303, as shown The CPU 314 uses the output to confrol the provision of MPEG slices to and from the buffer 303, to and from the RAM 312 and to and from the decoder 304 In other words, m Figure 3A, the CPU 314 controls the mput and output of the buffer 303 to accomplish scrollmg m a compressed picture which is larger than MPEG standard size in much die same way that the CPU 314 m Figure 3 controls the RAM 312 to provide slices to the decoder 304 to accomplish scrollmg More specifically, in Figure 3A, scrollmg m a compressed picture which is larger than MPEG standard size compnses the CPU 314 directing die buffer 303 and/or RAM 312 to provide the appropriate slices compnsmg the next desired portion of the compressed picture to be viewed for decodmg m response to received scrollmg mput Encoding Compressed Pictures Larger than Standard MPEG Size As discussed m the background section, MPEG-2 video bitstreams are generally compnsed of some combinanon of I (Intra-coded) pictures, P (predictively-coded) pictures, and B (Bidrrectionally-interpolated) pictures Each of the compressed pictures which are larger than MPEG standard m size are compnsed of a plurality of slices The MPEG-2 standard defines a slice as a contiguous sequence of 2 or more macroblocks (16x16 pixel blocks) that begm and end on die same row (of macroblocks) In e preferred embodiment, only I pictures are used for encodmg compressed pictures which are larger than MPEG standard size P and B pictures are preferably not used for encodmg the compressed pictures which are larger than MPEG standard size due to die inherent difficulties of creatmg these pictures witii the proper slice structure The header of die picture, and possibly other headers from the pieces of die picture, are stnpped off and placed in memory A pomter is preferably placed to po t to the header at the location m the slice (and or macroblock, etc as desired) for the location of die part of the picture which is to be displayed To enable vertical scrollmg, the simplest scenano is to encode each row of macroblocks mto a slice For a picture witii MPEG standard width, but witii longer length tiian standard MPEG, this encoded picture would resemble Figure 4A In this example, each row of macroblocks is encoded mto a slice One or more slices at the bottom and top of the picture are preferably mdependently compressed, meaning that a slice is encoded such tiiat it can be decoded without requiring references to macroblocks m other neighboring slices This mdependent encodmg of slices enables scrollmg to be performed, smce a slice can be decoded and displayed without requiring decodmg of a neighboring slice which is not bemg displayed It is noted mat a picture can be encoded without any slices bemg mdependently compressed However, this may require that slices be decoded which are not being displayed Multiple slices m the picture which are always displayed together may also be compressed together, I e , compressed dependently, if desired The following example of Figure 4A presumes that the user can scroll down individual horizontal slices one at a time, that the initial portion of the picture displayed was at the very top of the picture, and die user has scrolled down four times or slices In Figure 4A, the Current View is designated by the solid lmes The Current View is the result of having scrolled down four slices from the top of the picture The immediately previous view to the Cunent View, is refened to as Previous View and delimited witii the uniform wide dashed lmes The immediately previous view to the Previous View, is named as Second Previous View and delimited with the alternating wide and nanow dashed lmes The first view compnsmg the upper leftmost portion of die picture and the second view after that are not shown For a picture with MPEG standard length, but with wider width than standard MPEG, this encoded picture would resemble Figure 4B In this example, each row of macroblocks is encoded mto multiple slices The first few slices on the left side and the nght side are compnsed of only die minimum two macroblocks, while the slices m the middle of the picture may be composed of more than two macroblocks The slices on the left and nght sides are made small enough and mdependently compressed such that an MPEG standard size portion of the compressed picture is always available for mdependent decodmg and viewmg In otiier words, if d e compressed picture is, for example, 16 macroblocks wider than MPEG standard, then m this example there are at least four minimum sized slices of two macroblocks each on both the left and nght sides of die picture, along witii a set of possibly larger slices in the middle to allow for scrollmg completely across the compressed picture from left to nght and back In Figure 4B, the Current View is designated by the solid lines The Cunent View is die result of havmg scrolled nght once from the Previous View, delimited with wide dashed lmes Alternatively, if the picture is larger than MPEG standard in botii lengtii and widtii, a picture preferably is encoded with the slice structure similar to that shown in Figure 4C In this case, the first few slices on the left side and the nght side may be comprised of only the minimum two macroblocks, while the slices m the middle of the picture may be composed of more than two macroblocks As descnbed above, the slices on the left and right sides are made small enough and mdependently compressed such mat an MPEG standard size portion of the compressed picture is always available for mdependent decodmg and viewmg The slice structure of Figure 4C also allows for vertical scrollmg of the picture In Figure 4C, the Current View is designated by the solid lmes The Cunent View is the result of having scrolled nght once from the Previous View, delimited witii wide dashed lines Figure 5 - Encodmg Operation of the Prefened Embodiment Refemng now to Figure 5, a flowchart diagram is shown illustrating operation of the prefened embodiment of the present mvention in creatmg an encoded MPEG picture larger than standard MPEG size which can be scrolled Figure 5 illustrates the prefened embodiment, it bemg noted tiiat the present mvention may be implemented m vanous otiier ways Although the method is shown m flowchart form, it is noted tiiat certain of the steps in Figure 5 and 6 may occur concunently or m different orders As discussed above, die present invention compnses a system and metiiod for scrollmg m a picture which is larger than MPEG standard size m a video delivery system, preferably in an mteractive television system The interactive television system comprises a video delivery system for providmg video content, and at least one subscriber television mcludmg a display screen, wherein the subscnber television is coupled to die video delivery system The present invention also mcludes a system and method for encodmg a compressed picture with a proper slice structure for scrollmg The flowchart of Figure 5 shows how a picture larger than MPEG standard size is slice encoded and compressed for transmission to a subscriber television tiirough a video delivery system The flowchart of Figure 5 also shows how any desired tables compnsmg the starting pomts of slices are created along with the slice encodmg As shown m Figure 5, the method preferably operates as follows In step 500 encoder 106 or a similarly functional device receives an uncompressed picture which is preferably larger than MPEG standard size, I e , larger than standard MPEG lengtii or width or both The MPEG compression standard is preferably used as die reference standard for size, but otiier compression standards or methodologies could be used as desired, such as TIFF (Tagged Image File Format) among otiiers When another compression standard or methodology is used, the reference size would preferably be the size of a displayable image or the size of the portion of the image that would be desirable to view at any one tune, instead of die MPEG standard size When other compression standards or metiiodologies are used, the term "slice" shall mean a portion of the picture to be compressed which may be independently compressed by that standard or methodology In step 502 encoder 106 or a similarly functional device receives picture slice encodmg mformation In the prefened embodiment, the picture slice encodmg mformation comprises such information as how and where to create slices m the uncompressed picture, and which slices must be independently compressed This slice structure is preferably designed to allow for scrollmg m the picture such that all possible portions of the picture can be viewed on die subscriber television. In other words, the picture slice encoding information preferably includes enough information to allow encoder 106 to encode the uncompressed picture with a slice structure which has enough divisions to allow for smooth scrolling through the entire picture once the picture is compressed, transmitted, received and the desired portions of the picture are uncompressed. The picture slice encoding information may include a certain scrolling granularity which indicates the number of consecutive slices that are scrolled at one time. The number of consecutive slices that are scrolled at one time means that each scrolling input results in a jump of a set number of slices. This granularity can be accomplished by compressing blocks of slices mdependently, to a set number of slices compressed dependently together when the picture is MPEG compressed. This granularity can also be accomplished by die interactive application being programmed to cause each scrolling input to result in a jump or scroll a number of slices, even if the slices are each independently compressed. For example, consider a picture (not shown) which is MPEG standard width and is much longer than MPEG standard length. With a one row granularity, a single viewer input to scroll down in die image of this picture results in a single slice being removed from the top of the previous image witii a single new slice added to die bottom of the previous image to form a new viewable image. Scrolling from the top to the bottom of this picture then requires many scrolling inputs. With a larger granularity, such as 4 slices, viewer input to scroll down in die image of this picture results in 4 slices being replaced at die top of the previous image with an identical number of new slices at the bottom of the previous image to form a new viewable image. Scrolling from the top to the bottom of the picture then requires fewer scrolling inputs. The number of multiple slices being scrolled is preferably controllable by the system and/or die user. In step 504 encoder 106 or a similarly functional device compresses the uncompressed picture according to die picture slice encoding mformation. Preferably the compression metiiod is the MPEG standard method, aluiough it will be appreciated by ones skilled in the art that other compression schemes are contemplated, as mentioned above. If the picture being compressed has a lengtii or width which conforms to the MPEG standard, for example, then the encoded slices or groups of slices which make up the picture preferably likewise conform to the MPEG standard in length or widtii. Preferably, encoder 106 or a similarly functional device creates a table of starting points for each portion of the picture slice structure, as shown in step 506. While it would be possible for a decoder to search the slice structure for the starting locations of any given slice or group of slices, preferably a jump table is created, allowing for die starting point of any slice to be known without a search. Stated another way, the operation of compressing a picture larger than MPEG standard size, such that the compressed picture can be scrolled on a screen, preferably comprises an encoder receiving an uncompressed picture and picture slice encoding information. The encoder preferably then independently compresses slices or groups of slices according to the MPEG standard such tiiat the compressed picture can be scrolled in a display. The encoder then preferably creates a table of starting points for each slice or group of slices which has been independently compressed and/or which are scrollable. Figure 6 - Compressing a Non-Standard Sized Picture Refemng now to Figure 6, a flowchart diagram is shown conceptually illustrating step 504 of compressmg the uncompressed picture accordmg to the picture slice encodmg mformation It is noted tiiat the flowchart of Figure 6 is primarily conceptual, and die steps of Figure 6 may occur m vanous order or be implemented m different ways. As shown, step 504 generally compnses the following steps First, m step 600, the method compares the length of the uncompressed picture to the lengtii allowed by the MPEG standard. If the uncompressed picture is longer than MPEG standard, the method proceeds to step 602 In step 602 the method preferably divides the uncompressed picture mto slices and/or slice groups for mdependent compression on top and bottom borders to enable vertical scrolling to occur The picture slice encodmg mformation from step 502 is preferably used to decide where borders and scrollmg boundanes will occur. In die next step 604, die method compares the widtii of the uncompressed picture to the width allowed by the MPEG standard If the uncompressed picture is wider than MPEG standard, the method proceeds to step 606. In step 606, the method preferably divides the slice structure mto columns of slices on die left and nght borders where horizontal scrollmg may occur The final step 608 mvolves compressmg the slices accordmg to the MPEG standard In step 608, the method preferably mdependently compresses each individual slice or groups of slices, dependmg on the desired scrollmg granulanty. If groups of slices are present which would never scroll out of the viewmg area, those groups of slices may be compressed together as desired It is noted tiiat steps 602, 604 and 606 are generally performed together as an encodmg operation Therefore, the operation of the video delivery system or cable head-end can be summarized as follows. First a picture or unage is selected The picture has a size which may be larger than standard MPEG m lengtii or width or both Picture slice encodmg mformation is then created for the picture bitstream, preferably usmg the dimensions of the MPEG standard as a reference. A software encoder, which accepts the picture slice encodmg mformation, is used to encode the picture. A mutlrplexed signal is then created compnsmg: a) an mteractive application to perform all necessary operations, mcludmg scrollmg; b) the compressed picture bitstreams; c) any desired additional picture bitstreams; and d) any desired slice maps or byte offsets mto the additional picture bitstreams. This multiplexed stream can then be transmitted to one or more subscnber televisions Figure 7 - Scrollmg m a Portion of a Compressed Picture Refenmg now to Figure 7, a flowchart diagram is shown illustrating a method for scrollmg m a compressed picture larger than MPEG standard size accordmg to a first embodiment of the present mvention. It is noted tiiat the flowchart of Figure 7 is primarily conceptual, and the steps of Figure 7 may occur m vanous orders or be implemented m different ways. The method of Figure 7 is illustrated with respect to the compressed picture bemg transfened to a subscnber television from a video delivery system for viewmg. In step 700 die subscnber television receives some type of user mput selecting a picture for viewing Here it is presumed tiiat user mput is received which selects a picture which is larger than standard MPEG size In response to step 700, the subscnber television m step 702 requests the picture, or the initial or default portion of the picture, preferably the upper leftmost portion of the picture or the default view of the picture, from the video delivery system It is noted that the subscnber television may initially simply request the picture, and the video display system may be configured to mitially only provide the default portion or default slices In response to step 702, the video delivery system in step 704 provides the requested slices of the compressed picture to the subscriber television In this example, the picture chosen by user mput is larger than standard MPEG size and compressed accordmg to die present mvention The picture is compressed so that the requested slices allow die subscnber television to scroll through the compressed picture, as will be descnbed m die following steps of the method Upon receivmg the requested slices m step 704, the subscnber television displays the desired portion of the compressed picture m step 706 Further detail of step 706 is given below in die descnption of Figure 9 The subscnber television contmuously displays die unage of the requested picture displayed m step 706 until the subscnber television receives additional user picture selection mput m step 708 In step 708 the subscriber television receives a new input from the user regardmg which picture or portion of a picture is desired to be viewed, I e , whether a new picture is desired or scrollmg withm a cunent picture is desired In response to the received mput m step 708, the method determmes if a new picture is bemg requested by the user in step 710 This new picture would be a picture different from the picture cunently bemg displayed by the subscnber television m step 706 For example, the new picture might be chosen from a link m the cunent picture bemg displayed or might simply be a picture requested when the user issues a command to die subscriber television to display a different picture, such as by changmg a channel on a standard broadcast television In step 710, if die method determmes that a new, different picture has been requested, the method returns to step 702 and requests that the video delivery system provide the new picture Alternatively, if the user m step 708 has requested scrollmg m the present picture by providmg scrolling mput as determined in step 712, then operation advances to step 714 For example, if the picture bemg viewed is wider than MPEG standard, the user may mput a command to scroll left or nght in the image m order to view another portion of the picture If the picture bemg viewed is longer than MPEG standard, the user may input a command to scroll up or down m the image in order to view another portion of the picture For a picture which has a length or widtii or both m conformance with the MPEG standard, scrollmg for that respective direction is preferably disabled, unless the image has been enlarged on the screen and the image is then larger than that dimension of the viewmg screen Scrollmg, whether vertical or horizontal or both, is performed m step 714 as descnbed in die next section The result of the scrolling routine performed m step 714 is to set up new slices m the memory corresponding to the portion of the picture desired to be viewed In other words, the scrollmg routine uses die scrollmg mput received from the user to obtam the appropnate slices The scrollmg routine also preferably uses the slice table starting location to request the appropnate slices In response to the execution of the scrollmg routine m step 714, the method returns to the display routine m step 706 to display the desired portion of die picture indicated by the scrolling input The display routine operator transfers the slices from memory to the decoder for viewing Figure 8 - Scrolling Routme Referring now to Figure 8, a flowchart diagram illustrating die scrollmg routme performed m step 714 of Figure 7 is shown It is noted tiiat the flowchart of Figure 8 is pπmanly conceptual, and the steps of Figure 8 may occur m various orders or be implemented in different ways Step 714 may be broken down mto steps 752-756 In step 708, the subscriber television receives scrollmg mput from the user Step 708 conesponds to step 708 of Figure 7 where the user has provided scrollmg mput The scrollmg mput mdicates that the user presumably wishes to view another portion of the cunent picture which is not presently shown on the subscnber television The desired portion of the picture to be viewed may be above, below, to the left or to the nght of the cunently viewed portion of the picture For example, if the image cunently bemg displayed by die subscnber television is die upper leftmost portion of the picture, the user may request that the picture be scrolled down the picture's length or to the nght along the picture's width or a combmation of die two Obviously if the picture has a standard MPEG width, but a larger length than MPEG standard, the user can only scroll up or down Likewise if the picture has a standard MPEG length, but a larger width than MPEG standard, the user can only scroll left or nght In the prefened embodiment, the subscriber television does not or may not have enough memory m the RAM 312 or picture buffer 303 to store all portions of the picture in the subscnber television memory In response to scrollmg input m step 708, the method in step 752 requests the additional compressed slices from the video delivery system so at the picture may be scrolled as requested by the user In response to step 752, the video delivery system m step 754 provides the requested additional compressed slices to the subscnber television Upon receivmg the additional compressed slices requested m step 754, m step 756 the subscriber television stores the received additional compressed slices, possibly replacing m RAM 312 or the picture buffer 303 those slices no longer needed for display In step 756 the subscriber television mtegrates the received additional compressed slices witii those already stored in memory by the subscnber television The subscriber television preferably uses the slice map or table to aid m requesting and or mtegratmg the slices Figure 9 - Displaying a Portion of a Compressed Picture Referring now to Figure 9, a flowchart diagram illustrating the display routine performed in step 706 of Figure 7 is shown It is noted that the flowchart of Figure 9 is pπmanly conceptual, and die steps of Figure 9 may occur m vanous order or be implemented m different ways Step 706 may be broken down into die following steps In step 800 the subscriber television provides the portion of the compressed picture that is desired by the user to be viewed to the MPEG decoder The portion provided compnses a plurality of slices having a size conespondmg to a standard MPEG size In response to step 800, in step 802 the MPEG decoder receives the slices and decodes the portion of the compressed picture which is desired to be viewed In step 804 the MPEG decoder provides the decoded portion of the picture to the subscnber television In response to step 804, m step 806 the subscnber television displays the decoded portion of the picture The subscnber television may contmuously display the image of the decoded portion of the picture until anotiier image is desired to be viewed Figure 10 - Scrollmg in a Compressed Picture Referring now to Figure 10, a flowchart diagram illustrating a method is shown for scrollmg m a compressed picture larger than MPEG standard size accordmg to anotiier embodiment Figure 10 illustrates an embodiment similar to the embodiment of Figure 7, and mcludes an additional feature wherem the subscnber television can store one or more entire pictures m memory at the same time Thus, in this embodiment, the subscnber television is not required to request that other slices of a picture be provided by die video delivery system when other scrollmg mput is received, but rather all of the slices of a picture are present m memory It is noted that the flowchart of Figure 10 is primarily conceptual, and die steps of Figure 10 may occur in vanous orders or be implemented m different ways The method is illustrated witii respect to the compressed picture bemg transfened to a subscnber television from a video delivery system for viewmg The method starts when the subscnber television receives user mput selecting a picture for viewmg m step 900 In response to step 900, the subscnber television m step 902 preferably requests the desired compressed picture for viewmg from the video delivery system In response to step 902, the video delivery system m step 904 preferably provides all of the slices compnsmg the requested compressed picture to the subscriber television The compressed picture is compressed with a slice structure accordmg to the present mvention which enables the user to scroll the compressed picture, as will be descnbed m the following steps of the metiiod Upon receivmg the requested slices m step 904, the subscriber television displays a default portion of the compressed picture m step 706, preferably the upper leftmost portion of the picture Further detail of step 706 is given m the descnption of Figure 9 The subscriber television may contmuously display the image of the requested picture displayed m step 706 until such time as the subscnber television receives additional user picture selection mput in step 908 In other words, m step 908, die subscnber television receives a new mput from the user regardmg which picture or portion of a picture is desired to be viewed In response to step 908, the method determmes if a new picture is being requested by the user in step 910 A new picture is a picture different from the picture cunently bemg displayed by die subscnber television as part of step 706 For example, the new picture might be chosen from a link in the cunent picture bemg displayed or might simply be a picture requested when die user issues a command to the subscriber television to display a different picture, such as by changmg a channel on a standard broadcast television If die method m step 910 determmes mat a new, different picture has been requested, die metiiod returns to step 902 and requests that the video delivery system provide the new picture Alternatively, the method moves to step 912 In step 912, the method determmes if the user m step 908 has requested scrollmg m the present picture by providmg scrollmg mput For example, if the picture bemg viewed is wider than MPEG standard, the user may mput a command to scroll left or nght in die image m order to view another portion of the picture If the picture being viewed is longer tiian MPEG standard, the user may mput a command to scroll up or down m die image m order to view another portion of the picture For those pictures which have a length or widtii or both m conformance with the MPEG standard, scrollmg is preferably disabled unless die image has been enlarged on the screen and the image is then larger than the dimension of the viewmg screen Scrollmg whether vertical or horizontal or both, is earned out m step 914 described with reference to Figure 11 In response to the execution of the scrollmg routme m step 914, the method returns to die display routine m step 706. The display routme m step 706 execution is descnbed above with reference to Figure 9 Figure 11 - Scrolling Routme In die embodiment of Figure 10, the subscriber television has additional memory beyond the minimal amount present m the embodiment descnbed m Figures 7 and 8. This scrollmg method descnbed herein does not require additional slices from the video delivery system for scrollmg to occur. It is noted that the flowchart of Figure 11 is pnmanly conceptual, and die steps of Figure 11 may occur m vanous order or be implemented m different ways. Referring now to Figure 11, step 914 may be broken down mto the following steps In step 908, die subscnber television receives scrollmg mput from the user. The scrollmg mput mdicates that the user wishes to view anotiier portion of the cunent picture which is not presently shown on the subscnber television The desired portion of the picture to be viewed may be above, below, to the left or to the nght of the cunently viewed pomon of the picture For example, if the image cunently bemg displayed by die subscnber television is the upper leftmost portion of the picture, the user may request that the picture be scrolled down die picture's length or to the nght along the picture's widtii or a combmation of the two In die prefened embodiment, the subscnber television has sufficient memory to store the entire picture m the subscnber television memory In response to the scrollmg mput received m step 908, the method m step 952 integrates die necessary additional compressed slices for scrollmg m the desired manner with those previously displayed by die subscnber television A pomter pomts to the starting address in memory of each slice. Integration mvolves combmmg the set of pomters from the previous view with those additional pointers needed to provide the next desired view, while removmg those pomters from the set which mdicate slices m die previous view which are no longer needed for the next desired view. As noted above, die table of starting pomts for each slice is preferably created to aid the subscnber television in more easily scrollmg m a larger than standard compressed picture Where the table of starting points for each slice is not created and provided to the subscnber television, then the subscriber television is required to perform more processmg to complete the slice starting pomts and hence properly scroll the larger than standard picture. Conclusion Therefore, the present invention compnses an improved system and method for scrollmg m a compressed picture which is larger than MPEG standard m lengtii or widtii or both. Although die system and method of the present invention has been described m connection with the prefened embodiment, it is not mtended to be limited to die specific form set forth herem, but on the contrary, it is mtended to cover such alternatives, modifications, and equivalents, as can be reasonably mcluded within the spmt and scope of the mvention as defined by the appended claims

Claims: CLAIMS What is claimed is 1 A method for scrollmg through a picture m a subscnber television mcludmg a display screen, wherem the subscriber television is coupled to receive video content from a video delivery system, the method compnsmg the subscriber television receivmg at least a portion of a compressed picture, wherem said compressed picture compnses a plurality of slices, wherem at least a subset of said plurality of slices are mdependently compressed, wherein said compressed picture has a size greater than a standard MPEG picture, the subscnber television receivmg scrollmg mput from a user indicating a portion of said picture which is desired to be viewed, die subscriber television providmg a subset of said plurality of slices to an MPEG decoder in response to said scrollmg mput, wherem said subset of said plurality of slices conespond to said portion of said picture which is desired to be viewed, the subscriber television decodmg said subset of said plurality of slices to produce said portion of said picture which is desired to be viewed, the subscriber television displaying said portion of said picture after said decodmg 2 The method of claim 1, wherem said compressed picture is a compressed MPEG I picture 3 The method of claim 1, wherem said subset of said plurality of slices conespondmg to said portion of said picture which is desired to be viewed is a standard MPEG size 4 The method of claim 3, wherein said compressed picture has a length which is greater than a standard MPEG picture length, wherem said scrolling mput mdicatmg said portion of said picture which is desired to be viewed mdicates a portion of said length of said compressed picture 5 The method of claim 4, wherem said compressed picture has a width which is equal to a standard MPEG picture width, wherein said plurality of slices each have a widtii conespondmg to said standard MPEG picture width 6 The method of claim 4, wherem said compressed picture has a width which is greater than a standard MPEG picture widtii, wherem said compressed picture further compnses a plurality of columns of slices, wherem said scrollmg mput indicating said portion of said picture which is desired to be viewed mdicates a portion of said width of said compressed picture 7 The method of claim 3, wherem said compressed picture has a width which is greater than a standard MPEG picture width, wherem said compressed picture further compnses a plurality of columns of slices, wherem said scrollmg mput mdicatmg said portion of said picture which is desired to be viewed mdicates a portion of said widtii of said compressed picture 8 The method of claim 7, wherem said compressed picture has a length which is equal to a standard MPEG picture length, wherem each of said plurality of columns of slices have a length conespondmg to said standard MPEG picture lengtii 9 The method of claim 1 , further compnsmg the subscriber television displaying a default portion of said at least a portion of said compressed picture, after said receivmg said at least a portion of said compressed picture, wherem said default portion is a standard MPEG size 10 The method of claim 9, wherem said displaying said default portion mcludes providmg a first plurality of slices to the MPEG decoder wherem said subject of said plurality of slices conespondmg to said portion of said picture desired to be viewed mcludes one or more of said first plurality of slices and mcludes one or more second slices 11 The method of claim 1 , further compnsmg the subscnber television receivmg one or more slices of said compressed picture m response to said received scrollmg mput, wherem said one or more slices conespond to said portion of said picture which is desired to be viewed, wherem said providing said subset of said plurality of slices to the MPEG decoder mcludes providmg said one or more slices which were provided m response to said received scrollmg mput 12 The method of claim 1, wherem the subscriber television receivmg at least a portion of said compressed picture comprises receivmg a first plurality of slices of said compressed picture, wherem said first plurality of slices form said at least a portion of said compressed picture, wherem said portion of said picture which is desired to be viewed mcludes second one or more slices which are not mcluded m said first plurality of slices, the method further compnsmg the subscnber television receivmg said second one or more slices of said compressed picture in response to said received scrolling mput, wherem said second one or more slices conespond to said portion of said picture which is desired to be viewed, wherem said providmg said subset of said plurality of slices to the MPEG decoder includes providing said second one or more slices which were received m response to said received scrollmg mput 13 The method of claim 12, wherem said providmg said subset of said plurality of slices to the MPEG decoder mcludes providmg at least a subset of said first plurality of slices and providmg said second one or more slices which were provided m response to said received scrollmg mput 14 The method of claim 1, wherem the subscnber television receiving at least a portion of a compressed picture compnses the subscnber television receivmg an entire picture and stormg said entire picture in a memory, wherem said entire picture has a size greater than a standard MPEG picture, wherem said providmg said subset of said plurality of slices to the MPEG decoder in response to said scrollmg mput compnses providing said subset of said plurality of slices from the memory to the MPEG decoder 15 The method of claim 1, further compnsmg the subscnber television receivmg a table mdicatmg starting pomts of each of said plurality of slices compnsmg said compressed picture, and wherein said providmg said subset of said plurality of slices to the MPEG decoder mcludes usmg said table to determine starting pomts of said subset of said plurality of slices 16 The method of claim 1 , further compnsmg the subscriber television receivmg second scrollmg mput from a user mdicatmg a second portion of said picture which is desired to be viewed, providmg a second subset of said plurality of slices to the MPEG decoder m response to said second scrollmg mput, wherem said second subset of said plurality of slices conespond to said second portion of said picture which is desired to be viewed, decodmg said second subset of said plurality of slices to produce said second portion of said picture which is desired to be viewed, the subscnber television displaying said second portion of said picture after said decodmg 17 The method of claim 1 , wherem the subscnber television receivmg at least a portion of a compressed picture further compnses the subscnber television receivmg all of the slices of said compressed picture 18 The method of claim 1 , wherein the subscriber television receiving at least a portion of said compressed picture compnses receivmg a first plurality of slices of said compressed picture, wherein said first plurality of slices form said at least a pomon of said compressed picture, and wherein the subscriber television receivmg at least a portion of said compressed picture further compnses receivmg a second plurality of slices of said compressed picture, wherem said second plurality of slices are not included m said first plurality of slices, and wherem said pomon of said picture which is desired to be viewed mcludes one or more slices which are not included m said first plurality of slices, wherem said providmg said subset of said plurality of slices to the MPEG decoder mcludes providmg said mcludes said one or more slices which are not mcluded m said first plurality of slices, wherem said one or more slices which are not mcluded m said first plurality of slices are mcluded m said second plurality of slices of said compressed picture 19 A device which performs video decodmg and display operations for a subscnber television, wherein the device is operable for scrollmg through and displaying a picture, wherem the device compnses, an mput for receivmg a compressed picture, wherem said compressed picture compnses a plurality of slices, wherem at least a subset of said plurality of slices are mdependently compressed, wherem said compressed picture has a size greater than a standard MPEG picture, a decoder for decodmg received plurality of slices, a memory coupled to said mput which stores at least portions of said picture, wherem said memory is coupled to provide an output to said decoder, a processmg unit coupled to said memory which operates to provide a subset of said plurality of slices to the decoder in response to a scrollmg mput, wherem said subset of said plurality of slices conespond to said pomon of said picture which is desired to be viewed, and a decoder output coupled to said decoder and operable for couplmg to a display unit, wherem said decoder output provides said picture to said display unit 20 The device of claim 19, wherem said compressed picture is a compressed MPEG I picture 21 The device of claim 19, wherem said subset of said plurality of slices conespondmg to said portion of said picture which is desired to be viewed is a standard MPEG size 22 The device of claim 21, wherem said compressed picture has a length which is greater than a standard MPEG picture length, wherem said scrollmg mput mdicatmg said pomon of said picture which is desired to be viewed mdicates a portion of said length of said compressed picture 23 The device of claim 22, wherem said compressed picture has a width which is greater than a standard MPEG picture width, wherem said compressed picture further compnses a plurality of columns of slices, wherem said scrollmg mput mdicatmg said portion of said picture which is desired to be viewed mdicates a portion of said width of said compressed picture 24 The device of claim 21, wherem said compressed picture has a widtii which is greater than a standard MPEG picture width, wherein said compressed picture further compnses a plurality of columns of slices, wherem said scrollmg mput mdicatmg said portion of said picture which is desired to be viewed mdicates a portion of said width of said compressed picture 25 An mteractive television system for displaying a picture and for enablmg a user to scroll through the picture, wherem the mteractive television system compnses, a video delivery system for providmg video content, wherem the video delivery system provides a compressed picture, wherem said compressed picture comprises a plurality of slices, wherem at least a subset of said plurality of slices are mdependently compressed, wherem said compressed picture has a size greater than a standard MPEG picture, and at least one subscnber television, wherem the subscnber television is coupled to the video delivery system, wherem the subscriber television compnses a decoder for decodmg received slices, a memory coupled to said decoder which stores at least portions of said compressed picture, an mput for receivmg scrollmg mput from a user mdicatmg a pomon of said picture which is desired to be viewed, a processing unit coupled to said memoiy which operates to provide a subset of said plurality of slices to the decoder m response to said scrollmg mput, wherem said subset of said plurality of slices conespond to said portion of said picture which is desired to be viewed, and a display unit coupled to an output of said decoder for displaying the output of said decoder, wherem the display unit displays said portion of said picture after said decodmg 26 The system of claim 25, wherem said processmg unit directs said memory to provide slices from said compressed picture to accomplish scrollmg of said picture 27 The system of claim 26, wherem the video delivery system provides said compressed picture further compnsmg a table of starting pomts of each of said plurality of slices, wherem the processmg unit uses said table to determine location of said plurality of slices compnsed m said compressed picture 28 A method for creatmg an MPEG compressed picture m a video delivery system, wherem the compressed picture is adapted to be scrolled by a user on a viewmg device, the method compnsmg creatmg the compressed picture, wherem said compressed picture compnses a plurality of slices, wherein at least a subset of said plurality of slices are mdependently compressed, wherem said compressed picture has a size greater than a standard MPEG picture, creatmg a table mdicatmg starting pomts of each of said plurality of slices 29 The method of claim 28, wherem said creatmg the compressed picture compnses providmg a picture to an encoder, providing picture slice encodmg mformation to the encoder, wherem said picture slice encodmg mformation indicates a slice structure for said plurality of slices, encodmg the picture to create the compressed picture, wherem said encodmg uses said picture slice encodmg mformation m said encodmg to create said slice structure compnsmg said plurality of slices, wherem said encodmg uses said picture slice encodmg mformation to configure said slice structure of said plurality of slices accordmg to the scrollmg boundanes of the picture wherem at least a subset of said plurality of slices are mdependently compressed, creatmg a table mdicatmg starting pomts of each of said plurality of slices 30 The method of claim 28, wherem said compressed picture compnses an MPEG compressed I picture 31 The method of claim 30, wherem said compressed picture further compnses a width, wherem said compressed picture further comprises a set of columns of slices when said widtii is greater than a standard MPEG picture

Inventors: MCLAREN DAVID L, MCLAREN, DAVID, L.
Applicants: SUN MICROSYSTEMS INC, THOMSON CONSUMER ELECTRONICS, SUN MICROSYSTEMS, INC., THOMSON CONSUMER ELECTRONICS, INC.
Application year: 1998
Main classification: H04N7
IPC codes: G06T9, H04N7