1、 Reference number ISO/IEC 24800-4:2010(E) ISO/IEC 2010INTERNATIONAL STANDARD ISO/IEC 24800-4 First edition 2010-12-01 Information technology JPSearch Part 4: File format for metadata embedded in image data (JPEG and JPEG 2000) Technologies de linformation JPSearch Partie 4: Format de fichier de mtad
2、onnes incorpores dans des donnes dimage (JPEG et JPEG 2000) ISO/IEC 24800-4:2010(E) PDF disclaimer This PDF file may contain embedded typefaces. In accordance with Adobes licensing policy, this file may be printed or viewed but shall not be edited unless the typefaces which are embedded are licensed
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7、land ii ISO/IEC 2010 All rights reservedISO/IEC 24800-4:2010(E) ISO/IEC 2010 All rights reserved iiiContents Page Foreword iv Introduction.v 1 Scope1 2 Normative references1 3 Terms and definitions .1 4 Overview.2 5 JPSearch Metadata syntax .3 5.1 JPSearch Metadata Block overall structure .3 5.2 Ele
8、mentaryMetadata block .3 5.3 Syntax and semantics of Data block in an elementary metadata 5 5.4 Pre-registered metadata .6 6 JPSearch File structure 6 6.1 Overview.6 6.2 JPEG-1 and its compliant file formats.6 6.3 JPEG-2000 and its compliant file formats.7 ISO/IEC 24800-4:2010(E) iv ISO/IEC 2010 All
9、 rights reservedForeword 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 Standard
10、s 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
11、, 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 t
12、o 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 possibi
13、lity 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. ISO/IEC 24800-4 was prepared by Joint Technical Committee ISO/IEC JTC 1, Information technology, Subcommittee SC 29, Coding of
14、 audio, picture, multimedia and hypermedia information. ISO/IEC 24800 consists of the following parts, under the general title Information technology JPSearch: Part 1: System framework and components Part 2: Registration, identification and management of schema and ontology Part 3: Query format Part
15、 4: File format for metadata embedded in image data (JPEG and JPEG 2000) Part 5: Data interchange format between image repositories Part 6: Reference software ISO/IEC 24800-4:2010(E) ISO/IEC 2010 All rights reserved vIntroduction ISO/IEC 24800 (JPSearch) was developed to provide an interoperable mec
16、hanism to handle metadata among compliant systems including repository, search engine, and file entities. This part of ISO/IEC 24800 aims to provide a compatible mechanism exchange image data and its associate metadata using existing file formats. INTERNATIONAL STANDARD ISO/IEC 24800-4:2010(E) ISO/I
17、EC 2010 All rights reserved 1Information technology JPSearch Part 4: File format for metadata embedded in image data (JPEG and JPEG 2000) 1 Scope This part of ISO/IEC 24800, JPSearch, provides an interoperable data exchange format between various devices and platforms. It includes extensions of seve
18、ral existing file formats and file-format-independent metadata formats. 2 Normative references The following referenced documents are indispensable for the application of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced
19、 document (including any amendments) applies. ISO/IEC 10918-1, Information technology Digital compression and coding of continuous-tone still images: Requirements and guidelines ISO/IEC 15444-1, Information technology JPEG 2000 image coding system: Core coding system ISO/IEC 24800-2, Information tec
20、hnology JPSearch Part 2: Registration, identification and management of schema and ontology 3 Terms and definitions For the purposes of this document, the following terms and definitions apply. 3.1 metadata entity of data describing image resource 3.2 JPSearch metadata schema metadata schema registe
21、red according to the Metadata Registration Authority defined in ISO/IEC 24800-2 3.3 elementary metadata set of metadata entity compliant to one of the JPSearch metadata schema 3.4 JPEG JPEG-1 entity of code stream specification defined in ISO/IEC 10918-1 ISO/IEC 24800-4:2010(E) 2 ISO/IEC 2010 All ri
22、ghts reserved3.5 JPEG 2000 entity of code stream specification defined in ISO/IEC 15444-1 3.6 big endian byte ordering in a file used to represent integer value from the most significant byte NOTE The hexadecimal value 0x01234567 is stored as 0x010x230x450x67 using the big endian format. 3.7 JPSearc
23、h core metadata schema metadata schema defined in Clause 5 of ISO/IEC 24800-2 3.8 JPSearch Registration Authority registration authority defined in ISO/IEC 24800-2 who manages schema and translation rules 4 Overview Figure 1 illustrates a concept of JPSearch file format. It is designed as a full-com
24、patible file format with existing JPEG (Exif) and JPEG 2000 file format. It contains several JPSearchMetadata blocks which are a container of JPSearch metadata and each of them has one or more ElementaryMetadata blocks inside. ElementaryMetadata block is a basic structure of this specification. It s
25、tores an instance of certain metadata schema by certain author. Multiple instances for the same schema can be instantiated simultaneously to implement social tagging functionality. Any types of metadata schemes can be used if they are registered as JPSearch metadata using ISO/IEC 24800-2 framework.
26、JPSearchMetadata block (see 5.2) ElementaryMetadata block (see 5.3) An instance of JPSearch registered schema A by author B Data block (see 5.4) An instance of JPSearch registered schema C by author D An instance of JPSearch registered schema C by author E * One of Data block shall be an instance of
27、 JPSearch Core Metadata schema JPSearch File (JPEG compatible defined in 6.2, JPEG-2000 compatible defined in 6.3) Figure 1 Concept of JPSearch file format ISO/IEC 24800-4:2010(E) ISO/IEC 2010 All rights reserved 3In this Part of ISO/IEC 24800, Clauses 5 and 6 provide the specification of overall fi
28、le format and detailed structure of JPSearchMetadata block and ElementaryMetadata block, respectively. 5 JPSearch Metadata syntax 5.1 JPSearch Metadata Block overall structure A JPSearchMetadata block is a file-format-independent bit-stream to describe various kinds of metadata. It consists of one o
29、r more ElementaryMetadata block(s) as follows. JPSearchMetadata StartCode; VersionID; NumberOfElementaryMetadata; ElementaryMetadata; Table 1 Component semantics of in JPSearchMetadata block Tag Name Type length Semantics StartCode Fixed length string 4 bytes A 4-byte-length unique code to identify
30、the start point. JPS with a termination code (0x00) is used as the StartCode. VersionID unsigned char 1 bytes 0x01 is reserved for ISO/IEC 24800-4. Other values are reserved for future extensions. Note: VersionID will be changed only when the syntax of metadata box is modified. NumberOf Elementary M
31、etadata unsigned short (big endian) 2 bytes Specifying the number of ElementaryMetadata. Value 0xffff is reserved. The value 0 (0x0000) is prohibited. Elementary Metadata Binary stream - Describing ElementaryMetadata block (see 5.2) Note that additional bit stream may continue after ElementaryMetada
32、ta if VersionID is not 0x01. 5.2 ElementaryMetadata block An ElementaryMetadata block is designed to contain one instance of ElementaryMetadata. Multiple blocks shall be included in a file to carry several metadata instances written in different JPSearch metadata schema. Several blocks using the sam
33、e JPSearch metadata schema can be also instantiated simultaneously. JPSearch Part 4 compliant file format shall contain at least one elementary metadata block whose SchemaAndIdentifier is “JPSearch:schema:coremetadata“, which means that the block contain an instance of JPSearch core metadata schema.
34、 ISO/IEC 24800-4:2010(E) 4 ISO/IEC 2010 All rights reservedElementaryMetadata StartCode; LengthOfBlock; SchemaIdentifier; Annotation LengthOfAnnotation; ConfidentMeasure; Creation LastUpdateDateAndTime; LengthOfAuthor; Author; FlagReadOnly; LengthOfData; Encoding; Data; Table 2 Component semantics o
35、f ElementaryMetadata Tag Name Type length Semantics StartCode String 4 bytes A unique code to identify the start point. A string SEM with termination code (0x00) is used as StartCode. LengthOf Block Unsigned long (big endian) 4 bytes Specifying the size of elementary metadata block including StartCo
36、de. Schema Identifier URI string - Specifying the identifier of a registered schema to recognize the syntax and semantics of Data block. URI format is used with termination character 0x00 at the end. (See ISO/IEC 24800-2) Annotation Binary stream - Describing Annotation block (see Table 3) LengthOf
37、Data Unsigned long (big endian) 4 bytes Specifying the size of Data block in Bytes Encoding Unsigned char 1 byte Specifying the encoding method used for Data. Available values are shown in Table 4. Data Binary stream - Instance of metadata. The syntax of Data depends on Encoding and SchemaIdentifier
38、 as shown in 5.3. Compliant systems shall use LengthOfBlock to skip a elementary metadata block to have interoperability with future extensions where additional bits might be added after Data. ISO/IEC 24800-4:2010(E) ISO/IEC 2010 All rights reserved 5Table 3 Component semantics of Annotation block i
39、n ElementaryMetadata Tag Name Type Length Semantics LengthOf Annotation unsigned long (big endian) 4 bytes Specifying the size of Annotation block in byte. It should be noted that Annotation block may be extended in future. Confident Measure unsigned char 1 byte Lower 4 bits are valid and higher 4 b
40、its are reserved for future extensions. Describing the overall reliability of the data in range of 0, 15. The value The higher value means more confident. The value 0 (0x00) means that the following metadata is meaningless and 15 (0x0f) stands for completely reliable. Note that 15 (0x0f) can be used
41、 only by content creator, who captures the corresponding image. Creation DateTime ASCII 20 bytes Describing creation date/time of Data in GMT. The format shall be YYYY/MM/DD-HH:MM:SS(null). Here YYYY, MM, DD, HH, MM, SS denote year, month day, hour, minute, second respectively. (null) denotes the co
42、de 0x00. LastUpdate DateTime ASCII 20 bytes Describing the last update date/time of Data in GMT. The format shall be YYYY/MM/DD-HH:MM:SS(null). Here YYYY, MM, DD, HH, MM, SS denote year, month day, hour, minute, second respectively. (null) denotes the code 0x00. LengthOf Author unsigned char 1 byte
43、Specifying the size of Author field in byte. Note that the maximum size of the field including termination character code is limited to 256 byte. Author Unicode string Specified by LengthOfAu thor Describing the authors name of Data. Any Unicode string can be used. The string shall be terminated by
44、null(0x00) FlagRead Only Unsigned char 1 byte Specifying if the update of Data is allowed. 0x00 means allowed and 0xff not. Other values are reserved for future extension. Compliant systems shall use LengthOfAnnotation to reach the start position of LengthOfData to have interoperability with future
45、extensions where additional bits might be added after FlagReadOnly. 5.3 Syntax and semantics of Data block in an elementary metadata The syntax and semantics of Data block is depending on the metadata specification used as well as coding method identified by Encoding. Table 4 shows semantics of Enco
46、ding field used in ElementaryMetadata blocks. When Encoding is T (textual XML representation), a schema file to parse Data can be obtained from JPSearch Registration Authority using schema management procedure defined in ISO/IEC 24800-2. If Encoding is NUL, see the corresponding specification identi
47、fied by SchemaIdentifier to obtained syntax used. ISO/IEC 24800-4:2010(E) 6 ISO/IEC 2010 All rights reservedTable 4 Semantics of Encoding Value Semantics T (0x54) Data is written as an textual XML instance. The corresponding schema can be obtained using schema registration process defined in ISO/IEC
48、 24800-2. (recommended) B (0x42) Data is encoded using schema-supplier defined method. The syntax information to decode Data shall be provided by Registration Authority. NUL (0x00) No encoding method is identified. See the corresponding specification. Others Reserved for future extensions of ISO/IEC
49、 24800-4. 5.4 Pre-registered metadata Any metadata schema which has been registered and has a unique ID using ISO/IEC 24800-2 can be instantiated in a file; however, at least, an instance of JPSearch core metadata schema shall be included. Table 5 show the list of identifier which shall be recognized by ISO/IEC 24800-4 compliant systems. A registration mechanism of user-defined metadata shcema is specified in ISO/IEC 24800-2. Table 5 A list of pre-registered
