1、 International Telecommunication Union ITU-T T.800TELECOMMUNICATION STANDARDIZATION SECTOR OF ITU Amendment 6(03/2013) SERIES T: TERMINALS FOR TELEMATIC SERVICES Still-image compression JPEG 2000 Information technology JPEG 2000 image coding system: Core coding system Amendment 6: Updated ICC profil
2、e support, bit depth and resolution clarifications Recommendation ITU-T T.800 (2002) Amendment 6 ITU-T T-SERIES RECOMMENDATIONS TERMINALS FOR TELEMATIC SERVICES Facsimile Framework T.0T.19 Still-image compression Test charts T.20T.29 Facsimile Group 3 protocols T.30T.39 Colour representation T.40T.4
3、9 Character coding T.50T.59 Facsimile Group 4 protocols T.60T.69 Telematic services Framework T.70T.79 Still-image compression JPEG-1, Bi-level and JBIG T.80T.89 Telematic services ISDN Terminals and protocols T.90T.99 Videotext Framework T.100T.109 Data protocols for multimedia conferencing T.120T.
4、149 Telewriting T.150T.159 Multimedia and hypermedia framework T.170T.189 Cooperative document handling T.190T.199 Telematic services Interworking T.300T.399 Open document architecture T.400T.429 Document transfer and manipulation T.430T.449 Document application profile T.500T.509 Communication appl
5、ication profile T.510T.559 Telematic services Equipment characteristics T.560T.649 Still-image compression JPEG 2000 T.800T.829Still-image compression | JPEG XR T.830T.849 Still-image compression JPEG-1 extensions T.850T.899 For further details, please refer to the list of ITU-T Recommendations. Rec
6、. ITU-T T.800 (2002)/Amd.6 (03/2013) i INTERNATIONAL STANDARD ISO/IEC 15444-1 RECOMMENDATION ITU-T T.800 Information technology JPEG 2000 image coding system: Core coding system Amendment 6 Updated ICC profile support, bit depth and resolution clarifications Summary Amendment 6 to ITU-T T.800 (2002)
7、 | ISO/IEC 15444-1 (2004) clarifies the usage of ICC profiles to indicate colour spaces within the framework of ITU-T T.800 (2002) | ISO/IEC 15444-1 (2004). Specifically, it clarifies that matrix based display and matrix based input profiles are applicable. It was furthermore found that the definiti
8、ons for the tone mapping operations for grey scale and sRGB colour spaces of the colour specification box were only applicable for 8bpp input data, and hence did not allow the required bit-depth scalability JPEG 2000 follows otherwise. The definitions were extended to arbitrary bit depths, following
9、 the same principles as in ITU-T T.801 (2002) | ISO/IEC 15444-2 (2004) while restricting them to simple cases. Amendment 6 also improves and clarifies the definition of the Capture Resolution and Default Display Resolution boxes, and adds informative notes on their suggested usage. History Edition R
10、ecommendation Approval Study Group 1.0 ITU-T T.800 2002-08-29 16 1.1 ITU-T T.800 (2002) Amd. 1 2005-09-13 16 1.2 ITU-T T.800 (2002) Cor. 1 2007-01-13 16 1.3 ITU-T T.800 (2002) Cor. 2 2007-08-29 16 1.4 ITU-T T.800 (2002) Amd. 2 2009-03-16 16 1.5 ITU-T T.800 (2002) Amd. 3 2010-06-22 16 1.6 ITU-T T.800
11、 (2002) Amd. 4 2011-05-14 16 1.7 ITU-T T.800 (2002) Amd. 5 2012-01-13 16 1.8 ITU-T T.800 (2002) Amd. 6 2013-03-16 16 ii Rec. ITU-T T.800 (2002)/Amd.6 (03/2013) FOREWORD The International Telecommunication Union (ITU) is the United Nations specialized agency in the field of telecommunications, inform
12、ation and communication technologies (ICTs). The ITU Telecommunication Standardization Sector (ITU-T) is a permanent organ of ITU. ITU-T is responsible for studying technical, operating and tariff questions and issuing Recommendations on them with a view to standardizing telecommunications on a worl
13、dwide basis. The World Telecommunication Standardization Assembly (WTSA), which meets every four years, establishes the topics for study by the ITU-T study groups which, in turn, produce Recommendations on these topics. The approval of ITU-T Recommendations is covered by the procedure laid down in W
14、TSA Resolution 1. In some areas of information technology which fall within ITU-Ts purview, the necessary standards are prepared on a collaborative basis with ISO and IEC. NOTE In this Recommendation, the expression “Administration“ is used for conciseness to indicate both a telecommunication admini
15、stration and a recognized operating agency. Compliance with this Recommendation is voluntary. However, the Recommendation may contain certain mandatory provisions (to ensure, e.g., interoperability or applicability) and compliance with the Recommendation is achieved when all of these mandatory provi
16、sions are met. The words “shall“ or some other obligatory language such as “must“ and the negative equivalents are used to express requirements. The use of such words does not suggest that compliance with the Recommendation is required of any party. INTELLECTUAL PROPERTY RIGHTS ITU draws attention t
17、o the possibility that the practice or implementation of this Recommendation may involve the use of a claimed Intellectual Property Right. ITU takes no position concerning the evidence, validity or applicability of claimed Intellectual Property Rights, whether asserted by ITU members or others outsi
18、de of the Recommendation development process. As of the date of approval of this Recommendation, ITU had received notice of intellectual property, protected by patents, which may be required to implement this Recommendation. However, implementers are cautioned that this may not represent the latest
19、information and are therefore strongly urged to consult the TSB patent database at http:/www.itu.int/ITU-T/ipr/. ITU 2013 All rights reserved. No part of this publication may be reproduced, by any means whatsoever, without the prior written permission of ITU. ISO/IEC 15444-1:2004/Amd.6:2013 (E) Rec.
20、 ITU-T T.800 (2002)/Amd.6 (03/2013) 1 INTERNATIONAL STANDARD RECOMMENDATION ITU-T Information technology JPEG 2000 image coding system: Core coding system Amendment 6 Updated ICC profile support, bit depth and resolution clarifications 1) Clause 2.2 Additional References Add the following references
21、: - ISO 15076-1:2005, Image technology colour management Architecture, profile format and data structure Part 1: Based on ICC.1:1998-09, File format for Color Profiles. - ISO 15076-1:2010, Image technology colour management Architecture, profile format and data structure Part 1: Based on ICC.1:2010.
22、 2) Clause 4.1 Abbreviations Replace: ICC International Colour Consortium With: ICC International Color Consortium 3) Clause I.2.3 Greyscale, colour, palette, multi-component specification Replace: I.2.3 Greyscale, colour, palette, multi-component specification The JP2 file format provides two metho
23、ds to specify the colourspace of the image. The enumerated method specifies the colourspace of an image by specifying a numeric value that specifies the colourspace. In this Recommendation | International Standard, images in the sRGB colourspace and greyscale images can be defined using the enumerat
24、ed method. The JP2 file format also provides for the specification of the colourspace of an image by embedding a restricted form of an ICC profile in the file. That profile shall be of either the Monochrome or Three-Component Matrix-Based class of input profiles as defined by the ICC Profile Format
25、Specification, ICC.1:1998-09. This allows for the specification of a wide range of greyscale and RGB class colourspaces, as well as a few other spaces that can be represented by those two profile classes. See J.9 for a more detailed description of the legal colourspace transforms, how those transfor
26、ms are stored in the file, and how to process an image using that transform without using an ICC colour management engine. While restricted, these ICC profiles are fully compliant ICC profiles and the image can thus be processed through any ICC compliant engine that supports profiles as defined in I
27、CC.1:1998-09. In addition to specifying the colourspace of the image, this Recommendation | International Standard provides a means by which a single component palettized image can be decoded and converted back to multiple-component form by the translation from index space to multiple-component spac
28、e. Any such depalettization is applied before the colourspace is interpreted. In the case of palettized images, the specification of the colourspace of the image is applied to the multiple component values stored in the palette. ISO/IEC 15444-1:2004/Amd.6:2013 (E) 2 Rec. ITU-T T.800 (2002)/Amd.6 (03
29、/2013) With: I.2.3 Greyscale, colour, palette, multi-component specification The JP2 file format provides two methods to specify the colourspace of the image. The enumerated method specifies the colourspace of an image by specifying a numeric value that identifies the colourspace. In this Recommenda
30、tion | International Standard, images in the sRGB and sYCC colourspaces and greyscale images can be defined using the enumerated method. The JP2 file format also provides for the specification of the colourspace of an image by embedding one of a restricted subset of ICC Input and Display profiles in
31、 the file. The restricted subset of ICC profiles is defined in clause I.3.2. Their use allows for the specification of a wide range of greyscale and RGB class colourspaces, as well as some other spaces that can be represented by those two profile classes. In addition to specifying the colourspace of
32、 the image, this Recommendation | International Standard provides a means by which a single component palettized image can be decoded and converted back to multiple-component form by the translation from index space to multiple-component space. Any such depalettization is applied before the coloursp
33、ace is interpreted. In the case of palettized images, the specification of the colourspace of the image is applied to the multiple component values stored in the palette. 4) Clause I.3.2 Restricted ICC profile method Replace: I.3.2 Restricted ICC profile method An application may also specify the co
34、lourspace of an image using two restricted types of ICC profiles. This method handles the specification of the most commonly used RGB and greyscale class colourspaces through a low-complexity method. An ICC profile is a standard representation of the transformation required to convert one colourspac
35、e into another colourspace. With respect to the JP2 file format, an ICC profile defines how decompressed samples from the codestream are converted into a standard colourspace (the Profile Connection Space (PCS). Depending on the original colourspace of the samples, this transformation may be either
36、very simple or very complex. The ICC Profile Format Specification defines two specific classes of ICC profiles that are simple to implement, referred to within the profile specification as Monochrome Input and Three-Component Matrix-Based Input Profiles. These profiles limit the transformation from
37、the source colourspace to the PCSXYZ to the application of a non-linearity curve and a 3 3 matrix. It is practical to expect all applications, including simple devices, to be able to process the image through this transformation. Thus all conforming applications are required to correctly interpret t
38、he colourspace of any image that specifies the colourspace using this subset of possible ICC profile types. For the JP2 file format, profiles shall conform to the ICC profile definition as defined by the ICC Profile Format Specification, ICC.1:1998-09, as well as the restrictions specified above. Se
39、e J.9 for a more detailed description of the legal colourspace transforms, how those transforms are stored in the file, and how to process an image using that transform without using an ICC colour management engine. With: I.3.2 Restricted ICC profile method An application may also specify the colour
40、space of an image using a restricted subset of ICC profiles. This method handles the specification of the most commonly used RGB and greyscale class colourspaces through a low-complexity method. An ICC profile is a standard representation of the transformation required to convert one colourspace int
41、o another colourspace. With respect to the JP2 file format, an ICC profile defines how decompressed samples from the codestream are converted into a standard colourspace (the Profile Connection Space (PCS). Depending on the original colourspace of the samples, this transformation may be either very
42、simple or very complex. ISO 15076-1:2010 defines two classes of ICC profiles, Input and Display, with profile types that are simple to implement. They are the Monochrome and Three-Component Matrix-Based Input Profiles and the Monochrome and Three-Component Matrix-Based Display profiles. These profil
43、es limit the transformation from the source colourspace to the PCSXYZ to the application of either a non-linearity curve in the case of the Monochrome Input and Display profiles or a non-linearity curve and a 3 3 matrix in the case of the Three-Component Matrix-Based Input and Display Profiles. All
44、applications, including simple devices, are expected to be able to process the image through these transformations. All conforming applications are required to correctly interpret the colourspace of any image that ISO/IEC 15444-1:2004/Amd.6:2013 (E) Rec. ITU-T T.800 (2002)/Amd.6 (03/2013) 3 specifie
45、s the colourspace using this restricted subset of possible ICC profile types. Although restricted, these ICC profiles are fully compliant ICC profiles and the image can therefore be processed through any ICC compliant engine that supports profiles as defined in ISO 15076-1:2005. NOTE ICC.1:1998-09 s
46、pecifies what are known as V2 ICC profiles. The restricted ICC profile subset defined here are compatible with the most recent specification for the V2 ICC Profile Format, ISO 15076-1:2005. This was followed by a major revision of the ICC Profile Format to V4, which is specified in ISO 15076-1:2010.
47、 The move from V2 to V4 ICC profiles requires a change in Colour Management Modules (CMMs), which implement ICC-compliant colour transformations. However, it is common practice for V4 CMMs to support V2 profiles and the majority of profiles that a CMM has to process are still V2. For the JP2 file fo
48、rmat, profiles shall conform to the ICC profile definition as defined by ISO 15076-1:2005, including the restrictions specified above. Clause J.9 has a more detailed description of the legal colourspace transforms, how those transforms are stored in the file, and how to process an image using that t
49、ransform without using an ICC colour management engine. 5) Clause I.5.3.1 Image Header Box Add the following NOTE at the end of I.5.3.1: NOTE While clause I.5.3.1.1 defines the default image dimension in pixels, the relation to physical dimensions is given by the Capture Resolution Box (see I.5.3.7.1) and the Display Resolution Box (see I.5.3.7.2). Note that image pixels might not be square. 6) Clause I.5.3.3 Colour Specification box Replace the first paragraph of clause I.5.3.3: Each Colour Specification box de
