ISO/IEC 15444-1:2004/Amd 6:2013

INTERNATIONAL ISO/IEC
STANDARD 15444-1
Second edition
2004-09-15
AMENDMENT 6
2013-05-01
Corrected version
2013-11-15
Information technology — JPEG 2000
image coding system — Part 1:Core
coding system
AMENDMENT 6: Updated ICC profile
support, bit depth and resolution
clarifications
Technologies de l'information — Système de codage d'images
JPEG 2000 — Partie 1: Système de codage de noyau
AMENDEMENT 6: Support de profil ICC, profondeur de bit et
clarifications de la résolution mis à jour

Reference number
ISO/IEC 15444-1:2004/Amd.6:2013(E)
©
ISO/IEC 2013
ISO/IEC 15444-1:2004/Amd.6:2013(E)

©  ISO/IEC 2013
All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized otherwise in any form or by any
means, electronic or mechanical, including photocopying, or posting on the internet or an intranet, without prior written permission.
Permission can be requested from either ISO at the address below or ISO’s member body in the country of the requester.
ISO copyright office
Case postale 56  CH-1211 Geneva 20
Tel. + 41 22 749 01 11
Fax + 41 22 749 09 47
E-mail copyright@iso.org
Web www.iso.org
Published in Switzerland
ii © ISO/IEC 2013 – All rights reserved

ISO/IEC 15444-1:2004/Amd.6:2013(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 6 to ISO/IEC 15444-1:2004 was prepared by Joint Technical Committee ISO/IEC JTC 1,
Information technology, Subcommittee SC 29, Coding of audio, picture, multimedia and
hypermedia information, in collaboration with ITU-T. The identical text is published as
ITU-T Rec. T.800 (08/2002)/Amd.6.
This corrected version of ISO/IEC 15444-1:2004/Amd.6 replaces the version dated 2013-05-01.
© ISO/IEC 2013 – All rights reserved iii

ISO/IEC 15444-1:2004/Amd.6:2013 (E)
IN
TERNATIONAL 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:
– 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.
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 methods 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 enumerated
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 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 transforms 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 ICC.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 space. 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.
ITU-T Rec. T.800 (08/2002)/Amd.6 (03/2013) 1

ISO/IEC 15444-1:2004/Amd.6:2013 (E)
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 Recommendation |
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 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 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 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.
4) Clause I.3.2 Restricted ICC profile method
Replace:
I.3.2 Restricted ICC profile method
An application may also specify the colourspace 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 colourspace 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 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 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 the 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. See 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 colourspace 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 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 very 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 profiles 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 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
2 ITU-T Rec. T.800 (08/2002)/Amd.6 (03/2013)

ISO/IEC 15444-1:2004/Amd.6:2013 (E)
specifies 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 specifies 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. 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 format, 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 transform 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 defines one method by which an application can interpret the colourspace of the
decompressed image data. This colour specification is to be applied to the image data after it has been decompressed
and after any reverse decorrelating component transform has been applied to the image data.
With:
Each Colour Specification box defines one method by which an application can interpret the colourspace of the
decompressed image data. This colour specification is to be applied to the channel, representing signed or unsigned
integers, and associated to colours according to the Channel Definition Box (see clause I.5.3.6). The reconstructed
i
numerical values of channel number i are to be interpreted using the value BPC in combination with the relevant
colourspace definition.
i j
The symbol BPC is here defined as follows: It shall be identical to the value of the B field of the Palette Box (see
j
clause I.5.3.4) if channel i is the output of palette column j, or to the value of the Bits Per Component Box BPC if
channel i is the direct output of component j, or to the value of the BPC field of the Image Header Box if no Bits Per
i
Component Box is present. BPC identifies the number of bits (bit precision) of the numerical values carried by channel
i, including the sign bit if present, minus one.
If the colourspace is defined by an ICC profile, the input channels should carry unsigned values; usage of signed
i
samples is discouraged and currently not defined by the ICC. The values x of channel i shall be mapped to device
i
colour values d , as follows.
i i i BPCi+1
d = Lmax * x / (2 – 1)
i
Here, Lmax is the maximum input value associated with the relevant ICC tone reproduction curve.
i
If the colourspace is an enumerated colourspace and the values x for channel i are unsigned quantities, they shall be
i
mapped to colour values d according to
i i i i i BPCi+1
d = Lmin + (Lmax – Lmin ) * x / (2 – 1)
i i
for the purpose of establishing a correct interpretation with respect to the colourspace. Here, Lmin and Lmax are the
minimum and maximum allowed values for the relevant colour channel, in the numerical framework used to define the
colourspace.
i i
If, however, the values x for channel i, are signed quantities, they shall be mapped to colour values d according to
i i i i i (BPCi AND 0x7f)
d = Lzero + (Lmax – Lzero ) * x / (2 – 1)
ITU-T Rec. T.800 (08/2002)/Amd.6 (03/2013) 3

ISO/IEC 15444-1:2004/Amd.6:2013 (E)
i
for the purpose of establishing a correct interpretation with respect to the colourspace. Here Lmax is again the
maximum allowed value for the relevant colour, in the numerical framework used to define the colourspace, while
i
Lzero is the value of channel i in the representation of the colour that corresponds to the absence of any scene radiance,
the complete absorption of visible light or the achromatic level, if this interpretation is applicable and all channel values
are uniquely defined in this case.
i i i
Table I.10 defines both the enumerated colourspaces and the corresponding values of Lzero , Lmin and Lmax for this
Recommendation | International Standard.
Replace Table I.9 – Legal METH values:

Value Meaning
1 Enumerated Colourspace. This colourspace specification box contains the enumerated value of the colourspace
of this image. The enumerated value is found in the EnumCS field in this box. If the value of the METH field is 1,
then the EnumCS shall exist in this box immediately following the APPROX field, and the EnumCS field shall be
the last field in this box
2 Restricted ICC profile. This Colour Specification box contains an ICC profile in the PROFILE field. This profile
shall specify the transformation needed to convert the decompressed image data into the PCSXYZ, and shall
conform to either the Monochrome Inp
...