JPSearch RA

JPSearch Part 3: JPSearch query format

Part 3 of ISO/IEC 24800 contains the tools of the JPEG Query Format (JPQF) as an adaptation for the still images domain of ISO/IEC IS 15938-12 (MPEG Query Format). The goal of JPQF is to facilitate and unify access to search functionalities in distributed digital image repositories. To achieve this goal, the JPQF standard (in conjunction with ISO/IEC IS 15938-12) specifies precise input and output parameters to express requests and uniform client side processing of result sets, respectively. Moreover, the management component of JPQF covers searching and the choice of the desired services for retrieval. For this purpose, the standard provides a means to describe service capabilities and to undertake service discovery.

Essentially, JPQF is an XML-based query language that defines the format of the queries and replies exchanged between clients and servers in a distributed image search and retrieval system. The two main benefits of standardization of such a language are 1) interoperability between parties in a distributed scenario (e.g. content providers, aggregators and clients) and 2) platform independence (which also offers benefits for non-distributed scenarios). As a result, developers can construct applications exploiting image queries independent of the used service; this fosters software reusability and maintainability.

The following example shows a JPQF query which asks for images created the 2009-10-07T08:46:45:

<?xml version="1.0" encoding="UTF-8"?>
<JPEGQuery xmlns="urn:jpeg:jpqf:schema:2008" xmlns:mpqf="urn:mpeg:mpqf:schema:2008" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="urn:jpeg:jpqf:schema:2008 24800-3.xsd  urn:mpeg:mpqf:schema:2008 15938-12-Cor1-Cor2-Amd1.xsd" jpqfID="http://www.mpqf.org/id1">
  <InputQuery>
    <OutputDescription maxItemCount="3" maxPageEntries="10" outputNameSpace="urn:mpeg:mpeg7:schema:2004">   
      <mpqf:ReqField typeName="jpcs:uri">ImageInstanceLocator[1]</mpqf:ReqField>    
      <mpqf:ReqField typeName="jpcs:identifier">Identifier</mpqf:ReqField> 
      <mpqf:ReqField typeName="jpcs:Creators/GivenName">Creators/GivenName</mpqf:ReqField> 
      <mpqf:ReqField typeName="jpcs:Creators/FamilyName">Creators/FamilyName</mpqf:ReqField>  
      <mpqf:ReqField typeName="jpcs:CreationDate">CreationDate</mpqf:ReqField>    
      <mpqf:ReqField typeName="latitude">GPSPositioning/@latitude</mpqf:ReqField>
      <mpqf:ReqField typeName="longitude">GPSPositioning/@longitude</mpqf:ReqField>         
    </OutputDescription>
      <QueryCondition>      
        <EvaluationPath>/MovieBox/TrackBox/ItemMetaBox/JPSearchCore</EvaluationPath>       
          <Condition xsi:type="mpqf:Equal">            
            <mpqf:DateTimeField>CreationDate</mpqf:DateTimeField>
            <mpqf:DateTimeValue>2009-10-07T08:46:45</mpqf:DateTimeValue>          
          </Condition>                        
      </QueryCondition>
    </InputQuery>
</JPEGQuery>