ISO/IEC 15938-12:2008/Amd 1:2011
(Amendment)Information technology — Multimedia content description interface — Part 12: Query format — Amendment 1: Reference software and flat metadata output
Information technology — Multimedia content description interface — Part 12: Query format — Amendment 1: Reference software and flat metadata output
Technologies de l'information — Interface de description du contenu multimédia — Partie 12: Format de requête — Amendement 1: Logiciel de référence et sortie de métadonnées plates
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INTERNATIONAL ISO/IEC
STANDARD 15938-12
First edition
2008-12-15
AMENDMENT 1
2011-03-01
Information technology — Multimedia
content description interface —
Part 12:
Query format
AMENDMENT 1: Reference software and
flat metadata output
Technologies de l'information — Interface de description du contenu
multimédia —
Partie 12: Format de requête
AMENDEMENT 1: Logiciel de référence et sortie de métadonnées
plates
Reference number
ISO/IEC 15938-12:2008/Amd.1:2011(E)
©
ISO/IEC 2011
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ISO/IEC 15938-12:2008/Amd.1:2011(E)
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INTERNATIONAL ISO/IEC
STANDARD 15938-12
First edition
2008-12-15
AMENDMENT 1
2011-03-01
Information technology — Multimedia
content description interface —
Part 12:
Query format
AMENDMENT 1: Reference software and
flat metadata output
Technologies de l'information — Interface de description du contenu
multimédia —
Partie 12: Format de requête
AMENDEMENT 1: Logiciel de référence et sortie de métadonnées
plates
Reference number
ISO/IEC 15938-12:2008/Amd.1:2011(E)
©
ISO/IEC 2011
---------------------- Page: 1 ----------------------
ISO/IEC 15938-12:2008/Amd.1:2011(E)
PDF disclaimer
This PDF file may contain embedded typefaces. In accordance with Adobe's licensing policy, this file may be printed or viewed but
shall not be edited unless the typefaces which are embedded are licensed to and installed on the computer performing the editing. In
downloading this file, parties accept therein the responsibility of not infringing Adobe's licensing policy. The ISO Central Secretariat
accepts no liability in this area.
Adobe is a trademark of Adobe Systems Incorporated.
Details of the software products used to create this PDF file can be found in the General Info relative to the file; the PDF-creation
parameters were optimized for printing. Every care has been taken to ensure that the file is suitable for use by ISO member bodies. In
the unlikely event that a problem relating to it is found, please inform the Central Secretariat at the address given below.
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© ISO/IEC 2011
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electronic or mechanical, including photocopying and microfilm, without permission in writing from either ISO at the address below or
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ISO/IEC 15938-12:2008/Amd.1:2011(E)
Foreword
ISO (the International Organization for Standardization) and IEC (the International Electrotechnical
Commission) form the specialized system for worldwide standardization. National bodies that are members of
ISO or IEC participate in the development of International Standards through technical committees
established by the respective organization to deal with particular fields of technical activity. ISO and IEC
technical committees collaborate in fields of mutual interest. Other international organizations, governmental
and non-governmental, in liaison with ISO and IEC, also take part in the work. In the field of information
technology, ISO and IEC have established a joint technical committee, ISO/IEC JTC 1.
International Standards are drafted in accordance with the rules given in the ISO/IEC Directives, Part 2.
The main task of the joint technical committee is to prepare International Standards. Draft International
Standards adopted by the joint technical committee are circulated to national bodies for voting. Publication as
an International Standard requires approval by at least 75 % of the national bodies casting a vote.
Attention is drawn to the possibility that some of the elements of this document may be the subject of patent
rights. ISO and IEC shall not be held responsible for identifying any or all such patent rights.
Amendment 1 to ISO/IEC 15938-12:2008 was prepared by Joint Technical Committee ISO/IEC JTC 1,
Information technology, Subcommittee SC 29, Coding of audio, picture, multimedia and hypermedia
information.
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ISO/IEC 15938-12:2008/Amd.1:2011(E)
Information technology — Multimedia content description
interface —
Part 12:
Query format
AMENDMENT 1: Reference software and flat metadata output
In Clause 9, Output Description, 9.2 Syntax, add the highlighted part:
In Clause 9, Output Description, 9.3 Semantics, add this row at the end of the table
resultMode
If set to flat, specifies the desire that the selected metadata fragment appears in a
FragmentResult element in each result item. If the value of this attribute is not
specified, or is set to structured, the Description element will be used instead
(carrying all the metadata fragments selected by all the ReqField elements).
In Clause 9, Output Description, 9.3 Semantics, replace this row:
ReqField
Describes a data path within the item’s metadata, which a requester asks
to be returned. Paths are specified by making use of absolute XPath
expressions, which refer to the root of the item’s metadata, or optionally
using relative XPath expressions referred to a given schema’s complex
type.
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ISO/IEC 15938-12:2008/Amd.1:2011(E)
with:
ReqField
Describes a data path within the item’s metadata, which a requester
asks to be returned. Paths are specified by making use of relative XPath
expressions, which refer to the root of the evaluation item’s metadata
(the one specified by the EvaluationPath element), or optionally
using absolute XPath expressions referred to the root of the multimedia
content’s metadata (to which the evaluation item belongs). Depending
on the value of the resultMode attribute, the resulting metadata
fragments of the different ReqField elements will appear in several
ResultField elements or within a single Description element (or
two if a Join operation is used).
In Clause 9, Output Description, 9.4 Example, add the following example at the end (after the current
example):
This second example illustrates the use of resultMode attribute set to “flat“ to obtain a flat metadata
output. In this example, a simple free text query is specified which searches for textual descriptions containing
“San Jose”. In addition, the target domain is limited to images of the JPEG format. The OutputDescription
element is used to select two fields from the metadata of the resulting digital items (width and height of the
image), with the resultMode attribute set to “flat“.
outputNameSpace="urn:mpeg:mpeg7:schema:2004" >
resultMode="flat">MediaInformation/MediaProfile/MediaFormat/VisualCoding/Frame/@w
idth
resultMode="flat">MediaInformation/MediaProfile/MediaFormat/VisualCoding/Frame/@h
eight
image/jpeg
San Jose
The following is the example of an expected output by the specified OutputDescription above.
Title 01
640
480
Title 02
320
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ISO/IEC 15938-12:2008/Amd.1:2011(E)
200
Title 03
800
1000
In 13.2, ResultItem, 13.2.2 Syntax, add the highlighted part:
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ISO/IEC 15938-12:2008/Amd.1:2011(E)
maxOccurs="unbounded"/>
In 13.2, ResultItem, 13.2.3 Semantics, add this row at the end of the table:
FragmentResult
Contains a metadata fragment selected by a ReqField element in the output
description of the input query in a flat string form. It may be just a number like “65”, or
XML data which is packed as CDATA. It is an alternative way to the Description
element to get selected metadata from the result items.
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ISO/IEC 15938-12:2008/Amd.1:2011(E)
After Clause 14, Query Management Tools, add the following:
15 MPEG Query Format Reference Software
15.1 Introduction
The following Subclauses describe reference software for the normative clauses of this Part of
ISO/IEC 15938. The information provided is applicable for determining the reference software modules
available for this Part of ISO/IEC 15938, understanding the functionality of the available reference software
modules, and utilizing the available reference software modules.
In addition to the reference software, available (integrated) utility software that utilizes the reference software
is also described. This utility software can assist in understanding how to utilize the reference software, as
well as providing further insight into this Part of ISO/IEC 15938, e.g. informative Clauses.
15.2 MPQF Reference Software specific terms, definitions and conventions
15.2.1 Terms, definitions, symbols and abbreviated terms
15.2.1.1 module
software component implementing reference software or utility software
15.2.1.2 reference software
one or more modules utilizing normative parts of this Part of ISO/IEC 15938
15.2.1.3 utility software
one or more modules utilizing informative parts of this Part of ISO/IEC 15938 and/or the usage of reference
software within real-world applications
15.2.2 Conventions
In the remainder of this Clause, each reference and utility software module is described following the
convention as below:
Name of the ZIP file with the following structure:
//--.zip
: directory name in which the module can be found 15938-12
Module name
: name of the module, e.g., Parser, Validator, etc.
: letter A, B, C, etc. for different implementations.
: version number, i.e., n_n_n | n_n | n
Description Describes the functionality the module provides.
INPUT Describes the input of the module.
OUTPUT Describes the output of the module.
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ISO/IEC 15938-12:2008/Amd.1:2011(E)
Programming
Lists the programming language(s) in which the module is written.
Language(s)
Lists the platforms the module has been tested on and is supposed to run
Platform(s)
on.
Dependencies Lists the required libraries and code with version information.
Lists any implementation details, such as architecture diagrams and data
Details
flows.
15.3 Overview of the architecture of the 15938-12 reference software
MPQF Validator
XML Check
- XML well-formedness
MPQF
- XML schema validity
MPQF
internal
Parser
representation
MPEG Query
MPQF query
XML instance
Validation according
to the MPQF specification
output MPQF resultset
MPQF
Basic
Multimedia input content XML metadata
Interpreter
Content’s
XML metadata
Figure 5 — Reference/utility software architecture
The architecture (see Figure 5) of the Reference Software is divided in three different software modules, the
MPQF Validator, the MPQF Parser and the MPQF Basic Interpreter. These software modules are defined in a
composite way, the Basic Interpreter makes use of the Parser and the Parser makes use of the Validator.
The MPQF Validator first checks the XML well-formedness and validity of an MPQF input/output query
according to the rules of XML 1.1 and the MPQF XML schema. Secondly, the Validator checks if the input or
output query is compliant with the rules described in this part of ISO/IEC 15938 which cannot be enforced with
the XML schema.
Once the Validator has checked the validity of the MPQF query, the MPQF Parser translates this XML
instance into a Java object provided with methods for accessing and modifying the different parts of the query.
This Java object is the output of the Validator.
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ISO/IEC 15938-12:2008/Amd.1:2011(E)
The MPQF Basic Interpreter module receives from the Parser a Java object representing a query and also an
input XML file containing MPEG-7 metadata about a collection of images. However, note that MPQF is
metadata aqnostic and any other metadata format can be used in combination with the query format. The
Basic Interpreter will evaluate the query and will return another Java object representing the response (an
output query). This object is then passed to the Parser who will translate it to an XML output MPQF instance.
This Part of ISO/IEC 15938 comprises reference software modules. The following table summarizes the
modules:
module name description
MPQF Validator - XML well-formedness and schema validity
- Validation according to the MPQF specification
MPQF Parser - Parsing an MPQF instance into its internal data structure
- Serializing the internal data structure to a valid MPQF instance
Basic Interpreter Basic queries without query types
15.4 MPQF Validator
Module name /15938-12/MPQF_Parser-1_0_0.zip
- XML well-formedness and schema validity
Description
- Validation according to the MPQF specification.
INPUT An MPQF query; URI of the profile used (default = no profile).
- Well formed, not well formed + reasons why, valid, not valid +
reasons why (according to the MPQF XML schema)
OUTPUT
- Valid, not valid + reasons why (according to the MPQF
specification)
Programming
Java version 1.5 or higher
Language(s)
Platform(s) Any platform that supports the programming language
None
Dependencies
Details -
15.4.1 MPQF Validator Framework
The MPQF validator provides an extensible module based framework which allows an independent
development and assembly of verification components. Verification components can be divided into two main
groups: syntactic and semantic verification. Syntactic verification deals with the evaluation of XML documents
according to the following two characteristics: well-formed and valid. A XML document is well-formed if it
obeys the syntax of XML. Furthermore, a XML document is valid if it obeys the syntax of the underlying XML
Schema. Related to the MPQF validator, a MPQF query is syntactical correct if it is well-formed and valid
according to the MPQF XML Schema.
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ISO/IEC 15938-12:2008/Amd.1:2011(E)
Semantic verification deals with the evaluation of rules that are not expressed by syntactic means within the
XML Schema. For instance, a query may be valid for one multimedia retrieval service (MMRS) but invalid for
another one. In series, this can depend on different capabilities the individual MMRS support (e.g., different
query types are supported). Another semantic rule emerges in combination with internal references between
resources and query types. There are query types which reference to resources at the declaration level in
order to increase the reuse of components. However, specific query types are only allowed to point to specific
resources. This must be evaluated by the MPQF validator.
In order to support an extensible approach at the best, Figure 6 presents the internal workflow of the system.
Whenever an instance of the validator is created a corresponding validation chain is instantiated. A validation
chain consists of a set of validation modules which are selected for the individual validation process. An
overview of currently available validation modules is presented in 15.4.4.
The validation process evaluates the incoming MPQF query by traversing the validation chain step by step.
During this process every validation module verifies the query according to their specific rules (syntactic or
semantic). In case of an error, the validation stops and the respective error message is returned.
Figure 6 — Workflow of the MPQF validator
15.4.2 Class Hierarchy
Figure 7 demonstrates the class hierarchy of the MPQF validator, where in general three different parts can
be distinguished: public classes, validation modules and internal package. In the following, the individual parts
are explained in more detail.
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ISO/IEC 15938-12:2008/Amd.1:2011(E)
Figure 7 — Class Hierarchy
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ISO/IEC 15938-12:2008/Amd.1:2011(E)
15.4.3 Public classes
MPQFValidatorFactory
The MPQFValidatorFactory realizes the factory pattern software concept which allows the generation of
MPQFValidator instances. Furthermore, it provides a main method in order to use the software as a
standalone validator client. In this case, the syntactical validation is fixed to the XSV tool. The factory provides
a large set of configuration options. For instance, one has the possibility to deliver the MPQF-Schema, the
description Schema (schema which describes the information provided in an DescriptionResource field), the
query which should be evaluated, the classification scheme files and a service capability description file
determining the multimedia repository service which is the target for the execution of the query. Examples for
the usage of the factory are provided in 15.4.7.
MPQFValidator
The MPQFValidator is an interface which dictates the public methods of every validator implementation.
SyntacticalSubsystemException
In case this exception is thrown, it symbolizes a configuration error (e.g., wrong amount/type of parameter in
the command line) in one of the syntactical validation modules.
15.4.4 Validation Modules
15.4.4.1 Syntactic Validation
ValidateXSV
The ValidateXSV module accomplishes syntactic validation by using the XSV tool (see
http://www.ltg.ed.ac.uk/~ht/xsv-status.html).
ValidateAltova
The ValdiateAltova module accomplishes syntactic validation by using the Altova tool (see
http://www.altova.com/altovaxml.html).
ValidateXerces
The ValidateXerces module accomplishes syntactic validation by using the Xerces tool (see
http://xerces.apache.org/xerces-j/).
15.4.4.2 Semantic Validation
ValidateXQuery
The ValidateXQuery module evaluates an incoming query by verifying that, in case it contains one or more
QueryByXQuery elements, the XQuery expressions embedded in them satisfy the following constraints:
- The embedded XQuery expressions are compliant with the XQuery 1.0 specification (according to
the Saxon 9.0 implementation).
- It cannot be determined at compile time that the embedded XQuery expressions will return
something different from a Boolean value. Otherwise, they won’t be valid according to 12.10 of
this part of ISO/IEC 15938.
In case the module cannot determine at compile time the return type of an XQuery expression, it will be
considered valid and a warning message will be returned suggesting to the user wrapping the expression
within the XQuery’s fn:Boolean function.
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ISO/IEC 15938-12:2008/Amd.1:2011(E)
ValidateCapabilities
The ValidateCapabilities module evaluates an incoming query according to the given service capability
description of the target multimedia retrieval system (MMRS). During this test, it is verified whether all used
query types, algebraic operations, metadata formats, etc. are covered by the respective capability description.
ValidateGroupBy
The ValidateGroupBy module evaluates an incoming query according to GroupByField elements that
describes the key for grouping process. It is verified whether all GroupByField elements in GroupBy element
are also defined as ReqField elements in OutputDescription element.
ValidateResourceID
The ValidateResourceID module evaluates an incoming query according to the internal linkage of resources.
The module guarantees that resources are referenced correctly. Note that, this module should be enhanced
for verifying also type safety (e.g., description resource is only referenced by a QueryByDescription query
type).
ValidateGotInputQuery
The ValidateInputQuery module evaluates an incoming query by verifying that it contains a Query and Input
tag. This ensures that the XML instance document is a query request.
ValidateRelativeField
The ValidateRelativeField module evaluates an incoming query by verifying that if typeName is specified for
a DeclaredFieldType, only a relative XPath expression is allowed.
15.4.5 Internal Package
AbstractValidator
The AbstractValidator is an abstract class and implements the MPQFValidator interface. It provides some
basic functionality for XML parsing and processing. Furthermore, basic functionality for service capability
descriptions and classification schemes is given.
ValidationPart
The ValidationPart interface dictates the methods every validation module must implement. In order to keep
naming consistency, every validation module which is planned to be used within a validation chain must begin
with the name prefix Validate.
AbstractDOMHelper
This abstract class provides basic functionality for traversing (breadth search) the query which internally is
transferred to a DOM tree. Besides, the extraction of individual nodes within the tree is supported. Another
feature is the assistance in creating the result XML file containing the validator evaluation messages which is
forwarded to the user.
ErrorDescription
This class holds the final error message and provides means for its manipulation. The structure of the error
message is defined by the result messages XML Schema which is described in 15.4.6.
15.4.6 XSD Schema for Result Messages
The following XSD Schema describes the structure of a result message which can be collected after the last
validation module is executed. The result message can be retrieved by calling the getLastErrorXML() method.
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ISO/IEC 15938-12:2008/Amd.1:2011(E)
xmlns:mpqfval="urn:mpeg:mpqfval:schema:2006"
xmlns="http://www.w3.org/2001/XMLSchema"
elementFormDefault="qualified" attributeFormDefault="unqualified"
targetNamespace="urn:mpeg:mpqfval:schema:2006">
use="required"/>
use="required"/>
use="required"/>
...
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