Abstract:
A method and system for allowing a user to define and use custom metadata is disclosed. The method and system include providing a network accessible server with a metadata library comprising a plurality of metadata vocabularies. The server allows the user to create a custom metadata vocabulary by displaying a user interface on a client computer in which the user specifies a plurality of properties defining the custom metadata vocabulary. When the custom metadata vocabulary is defined, it is stored in the metadata library for subsequent access. The method and system further allow the user to search the metadata library to select at least one of the metadata vocabularies to apply to an electronic resource.

Description:
FIELD OF THE INVENTION  
         [0001]    The present invention relates to electronic storage and sharing of files and other web resources, and more particularly to a method and system for specifying, assigning, and maintaining user defined metadata in a network-based photosharing system.  
         BACKGROUND OF THE INVENTION  
         [0002]    Metadata has been associated with digital images, and is typically supported by online photosharing sites. However, digital image metadata has shared the same restrictions as metadata in general. It has been limited to standard metadata as defined by the various versions of the Exif standard. This metadata is of limited use to most users of digital images. Some cameras produce proprietary metadata, however, specialized PC software is required to parse, interpret, and store the image metadata. Some photo hosting sites support the specification of a limited amount of metadata. This metadata is restricted in that users cannot define new metadata fields or are limited to a fixed number of “user defined” fields. The ability to provide optional “user defined” metadata may be provided, but is limited because metadata support usually does not extend much beyond that defined by the Exif image file format standard. In addition, the methods the photoshosting sites use to store and transmit the metadata is propriety, making its use beyond that of the photohosting site limited. Further, searches are usually limited to only a subset of the limited metadata that is supported by a site.  
           [0003]    It is expected that camera manufacturers and photohosting sites will soon begin storing the metadata they support in XML or RDF (Resource Description Framework) format. This will go along way towards making this metadata useful to a large range of applications. RDF, developed by the World-Wide Web Consortium (W3C), provides a schema language for defining metadata vocabularies that allows interoperability between applications that exchange metadata. RDF allows descriptions of Web resources, which is any object with a uniform resource identifier (URI) as its address, to be made available in machine readable form. RDF is an application of XML and extends the XML model and syntax to be specific for describing resources. A resource is can be anything which can be uniquely identified. That is anything which can be assigned a URI. RDF supports a class system where a class specifies a set of properties and constraints on the possible values of those properties. These classes are specified using a schemal language, such as RDF Schema. A collection of property values associated with one or more of these classes is called an RDF description. Each of these properties has a property type and value specified in the associated schema. Schemas are identified uniquely by assigning each a URI. RDF utilizes the namespace facility of XML to point to a URI. Thus, the schema can be accessed at the URI identified by the namespace.  
           [0004]    Even though RDF enables metadata to be understandable to many applications and enables metadata to be infinitely extendable, the use of metadata by photosharing sites would still be problematic. The primary problem is that a user wishing to use these capabilities must understand the technical details of RDF to define his/her metadata.  
           [0005]    One problem with RDF, however, is that the syntax is complicated to learn, especially for a non-computer user. For instance, the following is a portion of the RDF syntax for describing a report:  
                                                                             &lt;Description about = “http://flashpoint.com./report.html”&gt;                &lt;DC:Title&gt; Specifying and Assigning Metadata &lt;/DC:Title&gt;           &lt;DC:Creator&gt; Paul Morris &lt;/DC:Creator&gt;           &lt;DC:Date&gt; 2001-01-01 &lt;/DC:Date&gt;           &lt;DC:Subject&gt; Metadata, RDF &lt;/DC:Subject&gt;                &lt;/Description&gt;            &lt;/RDF&gt;                  
 
           [0006]    Thus, users will not be able to specify metadata to suit his/her own particular needs without becoming an expert in RDF and XML. Further, even if the user took the time to learn RDF and XML, there is currently no mechanism to support for the storage, display, management, or use of this “user defined” metadata.  
           [0007]    Accordingly, what is needed is a system that allows a user to specify metadata for digital files that suits the user&#39;s own particular needs, provides storage/retrieval for this metadata, and integrates this metadata into its service, such as image presentation, searching, and grouping. Further, the system must enable this without requiring the user to understand the underlying technologies associated with the metadata schema and specification languages. The present invention addresses such needs. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0008]    [0008]FIG. 1 is a block diagram illustrating an online metadata management system in accordance with a preferred embodiment of the present invention.  
         [0009]    [0009]FIG. 2 is a flow chart illustrating the process of allowing users of the metadata management system to manage the metadata library.  
         [0010]    [0010]FIG. 3 is a flow chart illustrating the process of adding a new metadata vocabulary to the metadata library.  
         [0011]    [0011]FIG. 4 is a flow chart illustrating the process of assigning metadata from the vocabulary library to a target resource.  
         [0012]    [0012]FIG. 5 illustrates the process of allowing the user to associate optional metadata with a target resource that already exists in the photosharing site. 
     
    
     SUMMARY  
       [0013]    The present invention provides a method and system for allowing a user to define and use custom metadata. The method and system include providing a network accessible server with a metadata library comprising a plurality of metadata vocabularies. The server allows the user to create a custom metadata vocabulary by displaying a user interface on a client computer in which the user specifies a plurality of properties defining the custom metadata vocabulary. When the custom metadata vocabulary is defined, it is stored in the metadata library for subsequent access. The method and system further allow the user to search the metadata library to select at least one of the metadata vocabularies to apply to an electronic file or other target resource.  
         [0014]    According to the method and system disclosed herein, an online library of metadata vocabularies is provided from which users may create custom vocabularies using a form-driven interface without needing to understand the underlying semantics and syntax of the schema language.  
       DETAILED DESCRIPTION OF THE INVENTION  
       [0015]    The present invention relates to a method and system for specifying, assigning, and maintaining user-defined metadata in a network-based metadata management system. The following description is presented to enable one of ordinary skill in the art to make and use the invention and is provided in the context of a patent application and its requirements. Various modifications to the preferred embodiments and the generic principles and features described herein will be readily apparent to those skilled in the art. Thus, the present invention is not intended to be limited to the embodiments shown but is to be accorded the widest scope consistent with the principles and features described herein.  
         [0016]    The present invention provides a metadata management system that allows users of to specify custom metadata, assign the custom metadata to images, and manage the metadata. The present invention provides an online library of metadata vocabularies from which users may create custom vocabularies using a form-driven interface without needing to understand the underlying semantics and syntax of the schema language. In a preferred embodiment the vocabularies are specified using the RDF schema definition language specified by the W3C. (See www.w3.org/RDF/ for details of RDF and RDF schema languages.) Although RDF is expected to become the standard for specification and exchange of metadata on the web, any schema language with similar capabilities will work with this system.  
         [0017]    [0017]FIG. 1 is a block diagram illustrating an online metadata management system in accordance with a preferred embodiment of the present invention. According to the present invention, the system  10  includes a metadata management website  12  that includes a server  14 , and multiple client computers  16 . In a preferred embodiment, the server  14  can be accessed at a specific uniform resource locator (URL) address on the Internet or other network, and users  18  interact with the photosharing site  12  through a standard Web browser  19 .  
         [0018]    In a preferred embodiment, the metadata management system  10  is used in conjunction with a photosharing site and client computers  16  typically store the digital images  20  of a particular user  18 . The digital images  20  are stored as image files that include image data. Each image also has metadata  22  associated with it that describe and categorize the image. The metadata  22  may be associated with the images  20  by the user  18  or automatically by the server  14  as described below.  
         [0019]    According to the present invention, the metadata management site  12  allows users  18  to create, manage, and reuse metadata vocabularies and schema languages without requiring that the users  18  know the details of the metadata schema or exchange syntax. The present invention will be described in terms of a preferred embodiment where the targets to which the metadata is applied are digital images  20 , although the metadata  22  may be applied to any type of digital resource.  
         [0020]    The user  18  may upload the images  20  and the associated metadata  22  to the server  14  for storage. In the alternative embodiment of the present invention, the client computers  16  maintain storage of the actual image data and only the metadata  22  for each image are uploaded to the server  14 .  
         [0021]    In operation, users  18  of the client computers  16  register themselves with the server  14  to become members of the service so that they can specify, assign, and manage custom metadata. Once a member of the service, users  18  can search the server  14  for and reuse custom metadata defined by other users  18 .  
         [0022]    In a preferred embodiment, the server  14  includes a web server application  50 , a metadata vocabulary library  52 , and a user and group account database  54 . The metadata vocabulary library  52  is for storage and management of metadata schemas  84  or vocabularies. The vocabulary library  52  stores both custom metadata vocabularies  84  created by the users  18 , as well as actual metadata values associated with specific images  22  and uploaded from client computers  16 .  
         [0023]    In a preferred embodiment, the vocabulary library  52  includes a universal schema, shared schemas, and private schemas, which in a preferred embodiment are defined using RDF and XML. All images  20  in the system  10  are required to have associated with them metadata  22  specified by the universal schema. Each schema or vocabulary  84  specifies the metadata properties in that vocabulary and specifies constraints that must be enforced in order to comply with the vocabulary. The present invention allows users  18  and groups to define their own schemas, which may include the universal schema and may borrow from other vocabularies  84 .  
         [0024]    According to the present invention, the web server application  50  includes a form-driven user interface  66  that provides users  18  with an easy and intuitive way to define custom metadata vocabularies  84  without specifying the syntax for knowing the underlying schema language.  
         [0025]    For example, the homepage for the photosharing site  12  may display a web page having the following links: “Create A New Metadata Vocabulary” and “Search For A Metadata Vocabulary.” If the user clicks on the link to “Create New Metadata Vocabulary”, then one or more web pages may be displayed with a field for entering the title of the new metadata vocabulary, multiple fields for entering properties for the vocabulary, and fields for entering constraints on the values for each property.  
         [0026]    Assume, for example, that the same a user has taken photos of national parks and wishes to use the photosharing site  12  to create a custom metadata vocabulary for “national parks”. Possible properties the user could define for this new metadata vocabulary include the name of the park, its location (i.e. state and country), the names of objects in the picture, the category (e.g., wildlife, landscape, structure, etc). A possible constraint is that the country must be chosen from a list specified in the vocabulary schema, and the state must be chosen from a list which depends on the value of the country.  
         [0027]    It should be noted that the RDF schema language is not as complete as it could be with respect to specifying constraints. There are good reasons for this as identified by the W3C (see the RDF working group home page). Therefore, according a further aspect of the present invention, the user  18  is provided with the option of associating a vocabulary validator  24  with a newly defined metadata vocabulary  84  in the case were stronger constraints are needed. According to the present invention, the vocabulary validator  24  is a software program that runs on either the server or the client computers  16  that uses a plugin interface provided by the Web application  50 . For example, the plugin interface could define an interface compatible with Java&#39;s Enterprise java beans, or use a remote method invocation technology such as RMI or IIOP which makes the location of the validator unknown to the web application invoking it. The Web application  50  passes the metadata corresponding to the custom metadata vocabulary to the vocabulary validator  24  after it has ensured the constraints specified using the RDF schema have been enforced for further constrain enforcement. This process is described in more detail later.  
         [0028]    The Web application  50  provides metadata library management support that allows users with the appropriate permissions to not only add new metadata vocabularies  84  to the library  52 , but also to enter search terms in the user interface  66  to find existing metadata vocabularies  84  and properties. The user  18  may then add one or more existing metadata vocabularies  84  to the user&#39;s custom metadata vocabulary, or only select particular properties from the existing metadata vocabularies  84  to add to the user&#39;s custom metadata vocabulary. When user has completed the task of entering and/or selecting properties and constraints for the custom metadata vocabulary  84 , the newly created metadata vocabulary is stored in the metadata vocabulary library  52 .  
         [0029]    The user account database  54  stores user account and corresponding contact information and preferences of each registered user  18 . According to the present invention, groups and users may specify their own metadata  22  vocabularies and may share these vocabularies with other users and groups. Users and group administrators may specify one or more vocabularies, which must be supported for images associated with the user and group accounts, respectively. The server  14  and client computers  16  enforce these metadata requirements. Groups of users  18  may also share common policies, which may include permission settings, user interface options, required and optional metadata vocabularies  84 , subscriptions lists, and event/notification policies. In a preferred embodiment access control lists are maintained to control and restrict access. In alternate embodiment, role based permissions as supported by the Java Authentication and Activation Services may be supported.  
         [0030]    The user account database  54  allows mandatory vocabularies  84  to be associated with certain target resources. For example, a particular user  18  may want all of his individual photographs to have a certain set of metadata always supplied. His/her account would be configured to indicate the assignment of metadata supporting the relevant metadata vocabulary  84  is required before the image  20  may be stored on the system  10 . An example of required metadata, might be a vocabulary  84  for data about the owner of the account (e.g name, address, etc). Multiple vocabularies  84  may be required for any given target types.  
         [0031]    Digital still Images  20  need not be the only type of target resources. Examples of other types of image files for which required vocabularies may be specified include multiple image files, such as timelapse images, burst images, panarama images, etc. Non-image target resources may also be supported, such as sound files, movies, and text documents. The present invention applies to any resource that could conceivably have metadata associated with it.  
         [0032]    [0032]FIG. 2 is a flow chart illustrating the process of allowing users of the metadata management system to manage the metadata library  52 . Once the user logs-in, the Web application  50  displays one or more web pages that allows the user  18  to perform the following high-level functions. One management function is to allow the user to create vocabularies  84  to be added to the library  52  in step  106  (described further in FIG. 3).  
         [0033]    The second management function is to allow the user  18  to add references to metadata vocabularies existing elsewhere on the web to the library  52  in step  110  so they may be found by the search facilities provided by the Web application  50 . To add a reference to a metadata vocabulary existing external to the metadata library  52 , user  18  enters the name and URI for the metadata vocabulary in one of the user interface forms in step  112 , and clicks a link or button to create a new entry in the metadata library  52  in step  114 . See www.w3.org/RDF/ for details of how a vocabulary can reference elements of another vocabulary in order to borrow from it.  
         [0034]    The third management function is to allow the user  18  to set access permissions for the metadata vocabularies  84  in the metadata library  52  in step  118 . This is accomplished by selecting one or more metadata vocabularies  84  from the vocabulary library  52  in step  120  and setting the user permissions of the selected metadata vocabularies  84  in step  116 .  
         [0035]    [0035]FIG. 3 is a flow chart illustrating the process of adding a new metadata vocabulary  84  to the metadata library  52 . In response to the user  18  choosing to create a metadata vocabulary  84  in step  106  of FIG. 2, the Web application  50  gives the user  18  a choice to reuse properties from an existing vocabulary in step  206  or create a new property in step  214 . The user  18  may create new properties to be contained in the vocabulary by entering the property name and specifying the constraints, if any, for the possible values the property may contain in step  216  and  218 .  
         [0036]    For each new property the user  18  creates, the Web application  50  prompts the user  18  for the name of the property and allows the user  18  to select from a list of property types String, List, Boolean, Numeric, etc. The choices are limited to what the underlying specification language supports. Depending on the type, the Web application  50  may prompt the user  18  to provide additional constraints, such as the list of possible values for a list type or a range for a numeric range.  
         [0037]    If the user  18  chooses to reuse an existing vocabulary  84 , then a search facilities is presented in step  208  that allows the user  18  to locate existing vocabularies  84  based on user supplied criteria, such as the vocabulary identifier (i.e., its URI), the vocabulary&#39;s name, the name(s) of properties contained in the vocabulary, the owner of the vocabulary, or the intended target types of a vocabulary. That is, the library  52  supports metadata about the metadata vocabularies  84 . The search facility makes the vocabularies  84  easily browsable. The system  10  may at the option of the user  18  extend its search to include other metadata libraries (aka registries) as more of these libraries appear on the web.  
         [0038]    After the user enters search terms and finds existing vocabularies, the user  18  may select one or more properties from these vocabularies  84  in step  210  to add to the metadata vocabulary  84  being created. The user may optionally add additional constraints to the borrowed property (as allowed by RDF) in step  212 .  
         [0039]    As an example of reusing properties from an existing vocabulary and searching, consider a user who wants to create a metadata vocabulary  84  for describing pictures of his pets. He may begin by borrowing properties from the well-known Dublin Core metadata vocabulary, such as Title, Subject, and Description. He would do this by locating the Dublin core vocabulary using the search facility. In the search facility, he can enter the ID of the Dublin Core (i.e., its URI) or enter the names of one or more properties in the Dublin Core such as “subject”. Once the Dublin Core vocabulary is located and selected, the Web application  50  would display the properties available from the vocabulary allowing the user to select which elements to borrow. The user  18  may repeat this borrowing process from other vocabularies  84 . As the user  18  borrows properties, the Web application  50  allows the user to specify additional constraints. For example, the “Subject” property in the Dublin Core is a string (typically a string of keywords). The user  18  could select to restrict the string to one or more of a series of words from a list he specifies. When subsequently applying his custom metadata to images of his pets, the Web application  50  would display the list of pet names for the user to select from.  
         [0040]    As an additional option, the user  18  may supply a validator  24  to enforce contraints beyond those supported by the specification language. The validator  24  is a software program that supports a plugin API provided by the metadata library  52 . The validator  24  is called when metadata associated with the vocabulary is created or changed, but after the constraints enforced by the specification language have been verified.  
         [0041]    The processes of reusing existing vocabularies  84  and creating new properties may be repeated as needed until the user  18  is satisfied with the new metadata vocabulary  84  in step  202 . When the new metadata vocabulary  84  is complete, the metadata vocabulary  84  is named and saved in the metadata library  52  in step  204 .  
         [0042]    [0042]FIG. 4 is a flow chart illustrating the process of assigning required metadata from the vocabulary library to a target resource. When the Web application  50  receives a target resource to be added to the photosharing site  12  from the user  18 , the Web application  50  checks the user&#39;s account and the relevant group accounts that the user is a member of and retrieves the required vocabularies  84  specified for the type of target resource in step  302 . As stated above, any resource type may be supported, including images, sound files, movies, text files, and so on).  
         [0043]    Because the metadata vocabularies  84  often borrow properties from one another, the Web application  50  merges the required metadata vocabularies  84  retrieved from the library  52  in step  304  before prompting the user to enter values for the properties. The merging process performs two primary functions. First, it removes duplicate properties (that result from the borrowing of properties among vocabularies  84 ). Second, because the same property may have different sets of constraints specified by different vocabularies  84 , the Web application  50  ensures that policy for conflicting constraints is enforced. In a preferred embodiment, the most restrictive constraints are applied. In an alternate embodiment, the Web application  50  may allow the user to enter values that meet either constraint. A third possibility for constraint policy is to always choose the constraints in one particular vocabulary  84  over another. For example, two required vocabularies  84  may both borrow the property “subject” from the Dublin Core. Each of these vocabularies  84  may have specified additional constraints on what the value of “subject” may be.  
         [0044]    After merging vocabularies  84 , the Web application  50  builds the user interface by generating forms for metadata assignment in step  306  through which the user may enter values for the assigned metadata. In a preferred embodiment, the interface is a series of one or more forms displayed in the web browser  19 . In a preferred embodiment, XSLT is used to transform the RDF schema specification into XHTML forms for display in the user&#39;s web browser  19 . The user  18  is then allowed to navigate through the form(s) entering data in step  308 . The forms may display additional comments provided by the vocabularies  84  to aid the user  18  in entering the data values. As the user moves to an input field for a given property, the Web application  50  uses the constraints defined for the property to determine the correct form element to use for data input for any given property (a test field, a selection list, a choice list, and so on).  
         [0045]    As the user  18  enters values for the metadata, the Web application  50  validates the metadata values based on the vocabulary constraints and optionally supplied vocabulary validator  24 (s) in step  310 . When the data is valid and the user  18  is finished entering metadata values, the Web application  50  associates the metadata with the target resource and saves in step  312 .  
         [0046]    [0046]FIG. 5 illustrates the process of allowing the user  18  to associate optional metadata with a target resource that already exists in the management site  12 . In other words, this process allows the user  18  to add metadata for the target resource that was not otherwise required for that resource type. In a preferred embodiment, the user  18  may add metadata to any target to which he/she has access. The user  18  first searches and/or browses for metadata vocabularies  84  as needed to add the desired metadata to the target in step  402 . The user  18  then selects vocabularies  84  to use in step  404 . Note: If the user  18  can&#39;t find the needed properties in existing vocabularies  84  the user  18  can create a new one, as described with reference to FIG. 3.  
         [0047]    After the user has selected vocabularies to use, the process proceeds as described with reference to FIG. 4: merging the vocabularies (step  406 ), generating forms for metadata assignment (step  408 ), displaying the forms and accepting user input (step  410 ), and validating the metadata values based on the vocabulary constraints and optional vocabulary validator  24   s  (step  412 ). The user  18  may continue by searching for more vocabularies to add to the target resource in step  402 . When user  18  is done in step  414 , the metadata is associated with the target resource and saved in step  416 .  
         [0048]    As an example of adding optional metadata to images consider the following example. Assume that the user  18  has added an image of a family with mountains in the background to the system  10 . Assume further that the user  18  has defined a private schema that includes the universal schema, borrows from a shared schema defined for family metadata, and has added additional metadata for the user&#39;s  18  private use. Another user  18  may discover the image, perhaps through a search using fields in the universal schema. Seeing the mountains in the picture and being an avid fan of nature photography this user creates nature metadata to associate with image using a shared schema defined for nature photographs. The user then uploads this metadata for the image to the server  14 . Other users constructing searches built using one or more of these vocabularies (universal, family, user&#39;s private extensions, and nature) will be able to find image if the search criteria match.  
         [0049]    According to the present invention, the photosharing system allows users to create custom metadata and to make the custom metadata available for other users in the system to use. The schema definitions are not limited by the system  10 . Further, the system allows the users to add and reuse the metadata stored in the system without requiring users to know underlying details regarding the schema language and syntax.  
         [0050]    A method and system for specifying, assigning, and maintaining user defined metadata in a network-based metadata management system has been disclosed. The present invention has been described in accordance with the embodiments shown, and one of ordinary skill in the art will readily recognize that there could be variations to the embodiments, and any variations would be within the spirit and scope of the present invention. Accordingly, many modifications may be made by one of ordinary skill in the art without departing from the spirit and scope of the appended claims.