1、 INTERNATIONAL TELECOMMUNICATION UNION ITU-T T.801TELECOMMUNICATION STANDARDIZATION SECTOR OF ITU Corrigendum 3(01/2005) SERIES T: TERMINALS FOR TELEMATIC SERVICES Information technology JPEG 2000 image coding system: Extensions Technical Corrigendum 3 ITU-T Recommendation T.801 (2002) Technical Cor
2、rigendum 3 ITU-T Rec. T.801 (2002)/Cor.3 (01/2005) i INTERNATIONAL STANDARD ISO/IEC 15444-2 ITU-T RECOMMENDATION T.801 Information technology JPEG 2000 image coding system: Extensions Technical Corrigendum 3 Summary This Corrigendum provides corrections to the descriptions of the Animation and Compo
3、siting data structures within the JPX file format. NOTE ISO/IEC 15444-2 Amendment 1 and Technical Corrigenda 1 and 2 are already integrated in T.801 approved by ITU-T on 2002-08. Source Corrigendum 3 to ITU-T Recommendation T.801 (2002) was approved on 8 January 2005 by ITU-T Study Group 16 (2005-20
4、08) under the ITU-T Recommendation A.8 procedure. An identical text is also published as Technical Corrigendum 3 to ISO/IEC 15444-2. ii ITU-T Rec. T.801 (2002)/Cor.3 (01/2005) FOREWORD The International Telecommunication Union (ITU) is the United Nations specialized agency in the field of telecommun
5、ications. 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 worldwide basis. The World Telecommunic
6、ation 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 WTSA Resolution 1. In some areas of
7、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 administration and a recognized operating
8、 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 provisions are met. The words “shall“ or s
9、ome 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 to the possibility that the practice o
10、r 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 outside of the Recommendation development
11、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, implementors are cautioned that this may not represent the latest information and are therefore strongl
12、y urged to consult the TSB patent database. ITU 2005 All rights reserved. No part of this publication may be reproduced, by any means whatsoever, without the prior written permission of ITU. ITU-T Rec. T.801 (2002)/Cor.3 (01/2005) iii CONTENTS Page 1) Clause M.5.1 1 2) Clause M.5.1.1 1 3) Clause M.5
13、.3.2.1. 1 4) Clause M.11.1 2 5) Clause M.11.5 2 6) Clause M.11.5.1 2 7) Clause M.11.7.7 2 8) Clause M.11.10.1 4 9) Clause M.11.10.2 5 10) Clause M.11.10.2.1. 5 11) Clause N.3 5 ISO/IEC 15444-2:2005/Cor.3:2005 (E)ITU-T Rec. T.801 (2002)/Cor.3 (01/2005) 1 INTERNATIONAL STANDARD ITU-T RECOMMENDATION In
14、formation technology JPEG 2000 image coding system: Extensions Technical Corrigendum 3 1) Clause M.5.1 Add a new subclause to clause M.5.1 (Mapping codestreams to compositing layers): M.5.1.3 Establishing a sequence order for codestreams A sequence order for codestreams is required for the subsequen
15、t ordering of compositing layers and in particular for the case where one or more compositing layers comprises more than one codestream. Codestreams are assigned a sequence order equal to their position in the file, starting with zero. In the case where a Fragment Table box is used, the Fragment Tab
16、le box is considered equivalent to a Contiguous Codestream box for the purpose of establishing a codestream sequence order for the referenced codestream. 2) Clause M.5.1.1 Amend paragraph 2 of clause M.5.1.1 (Establishing a sequence order for compositing layers) as follows: If a Component Registrati
17、on box is present in any Compositing Layer Header box, then there shall be one Component Registration boxCompositing layer header box infor every Compositing Layer Header box in the file, each containing at least one Component Registration box. In this case, the order of compositing layers is given
18、by the sequence order of compositing layer header boxes in the file. 3) Clause M.5.3.2.1 Amend the text in the second bullet of clause M.5.3.2.1 (Special cases of life and persistence) as follows: When PERSIST is true and LIFE is zero then this instruction should be executed together with the next i
19、nstruction. In practice this combination may occur for a sequence of more than two instructions and shall place the reader into a frame composition mode. This mode is exited when an instruction with non-zero PERSIST LIFE is encountered or when the end of the animation is reached. The set of instruct
20、ions executed whilst in frame composition mode is referred to as a frame composition sequence. In frame composition mode, a virtual compositing layer is created (off-screen) by executing the instructions in the frame definition sequence. The PERSIST and LIFE parameters for the closing instruction of
21、 a frame definition are applied to the virtual compositing layer as a whole. This mode permits multi-sprite animationThat is, upon close of frame composition mode, all of the compositing layers involved in the frame composition sequence acquire the PERSIST and LIFE values of the closing frame in the
22、 sequence. ISO/IEC 15444-2:2005/Cor.3:2005 (E) 2 ITU-T Rec. T.801 (2002)/Cor.3 (01/2005) 4) Clause M.11.1 a) Amend the SFifield definition of clause M.11.1 (Reader Requirements box) as follows: SFi: Standard flag. This field specifies a standard feature flag. The number of SFifields shall be equal t
23、o the value of the NSF field. This field is encoded as a 2-byte big endian unsigned integer. Legal values of this field are shown in Table M.14 Legal values of this field are specified in Table M.14 and in extensions to this standard. b) Add a new row to Table M.14 (Legal values of the SFi field) de
24、fining Value 70: Table M.14 Legal values of the SFifield Value Meaning1 Codestream contains no extensions 65 Compositing layers have different colour spaces 66 Compositing layers have different metadata 70 Compositing layer uses sYCC enumerated colour space 5) Clause M.11.5 Amend the text in paragra
25、ph 2 of clause M.11.5 (JP2 Header box (superbox) as follows: Also, if the codestream isJP2 Header box specified by the JP2 Header boxdefault information for any codestreams, then the semantic relationship of the Image Header box and Bits Per Component box contained within the JP2 Header box shall fo
26、llow the rules defined in M.11.5.1 and M.11.5.2 respectively. 6) Clause M.11.5.1 Replace the entire definition of the IPR field in clause M.11.5.1 (Image Header box) as follows: IPR: Intellectual Property. The value of this field is identical to that defined for the JP2 file format.This parameter in
27、dicates whether this JPX file contains intellectual property rights information that is associated with the codestream or codestreams described by this Image Header box. If the value of this field is 0, those codestreams do not have associated rights information. If the value is 1, then those codest
28、reams do have associated rights information. Other values are reserved. 7) Clause M.11.7.7 Amend clause M.11.7.7 as follows: M.11.7.7 Codestream Registration box When combining multiple codestreams to create a single compositing layer, it is important that the reference grids of those codestreams be
29、 properly registered to ensure the registration of the individual samples from the multiple components. This box specifies how those codestreams shall be registered when rendering the layer. A Compositing Layer Header box shall contain zero or one Codestream Registration boxes, and Codestream Regist
30、ration boxes shall be found in no other locations in the file; a Codestream Registration box shall not be placed into the JP2 Header box to specify a default registration. If any Compositing Layer Header box contains a Codestream Registration box, then every Compositing Layer Header box shall contai
31、n a Codestream Registration box. If this Compositing Layer Header box does not contain a Codestream Registration box, then the compositing layer shall be represented by one and only one codestream. ISO/IEC 15444-2:2005/Cor.3:2005 (E)ITU-T Rec. T.801 (2002)/Cor.3 (01/2005) 3 If codestream registratio
32、n is not specified for a particular compositing layer, then the codestreams in that compositing layer shall be aligned by directly aligning their reference grids at both (0,0) and (1,1). If a Codestream Registration box exists, then the default display resolution (specified within a Resolution box w
33、ith the same Compositing Layer Header box) applies to the compositing layer registration grid. This registration is specified with respect to an independent compositing layer registration grid. The type of the Codestream Registration box shall be creg (0x6372 6567). The contents of this box shall be
34、 as follows: T.801_FM-23CDNnCDN0XS YSXR0YR0XO0YO0XRnYRnXOnYOnFigure M.23 Organization of the contents of a Codestream Registration box The fields of the codestream registration box may be interpreted in the context of the following equations defining the scaling factors RXiand RYiof the ith codestre
35、am in x and y: RXi= XRi / XS RYi= YRi/ YS and the offsets OXiand OYiof the ith codestream in x and y: OXi= XOi/ XS OYi= YOi/ YS on the compositing layer registration grid. The overall area of the registration grid is defined to be the intersection of the areas covered by the scaled and offset compon
36、ent codestreams grown out as required to the nearest whole integer registration grid point. The requirement that XOi XS and YOi YS ensures that this intersected area always includes the origin (0,0) of the compositing layer registration grid. If a Codestream Registration box exists, then the default
37、 display resolution (specified within a Resolution box with the same Compositing Layer Header box) applies to the compositing layer after all components have been rescaled and registered. XS: Horizontal grid size. This field specifiesdefines the number of horizontal fractional grid points from (0, 0
38、) to (1, 0) on the compositing layer registration grid. These fractional grid points are used to measure the distance between the reference grids of the individual codestreams. This field is encoded as a 2-byte unsigned integer. YS: Vertical grid size. This field specifiesdefines the number of verti
39、cal fractional grid points from (0, 0) to (0, 1) on the compositing layer registration grid. These fractional grid points are used to measure the distance between the reference grids of the individual codestreams. This field is encoded as a 2-byte unsigned integer. CDNi: Codestream number. This fiel
40、d specifies the number of the codestream for this registration value. XRi: Horizontal resolution. This field specifies the horizontal distance between points on the reference grid of the codestream specified by the CDNiparameter, measured in the number of fractional points on the compositing layer r
41、egistration grid. This field effectively specifies the horizontal scaling needed to match the codestreams reference grid with the compositing layer registration grid. This field is encoded as a 1-byte unsigned integer. YRi: Vertical resolution. This field specifies the vertical distance between poin
42、ts on the reference grid of the codestream specified by the CDNiparameter, measured in the number of fractional points on the compositing layer registration grid. This field effectively specifies the vertical scaling needed to match the codestreams reference grid with the compositing layer registrat
43、ion grid. This field is encoded as a 1-byte unsigned integer. XOi: Horizontal offset. This field specifies the horizontal distance (to the right) from the origin of the compositing layer registration grid to the centre of the top left point on the reference grid of the codestream specified by the CD
44、Niparameter to the centre of the top left point on the compositing layer registration grid This field is encoded as a 1-byte unsigned integer. Its value must be strictly less than the value of XS. ISO/IEC 15444-2:2005/Cor.3:2005 (E) 4 ITU-T Rec. T.801 (2002)/Cor.3 (01/2005) YOi: Vertical offset. Thi
45、s field specifies the vertical distance (downward) from the origin of the compositing layer registration grid to the centre of the top left point on the reference grid of the codestream specified by the CDNiparameter to the centre of the top left point on the compositing layer registration grid This
46、 field is encoded as a 1-byte unsigned integer. Its value must be strictly less than the value of YS. Table M.35 Format of the contents of the Codestream Registration box Field name Size (bits) Value XS 16 0-65 535 YS 16 0-65 535 CDNi16 0-65 535 XRi8 0-255 YRi0-255 XOi0-255 YOi8 0-255 8) Clause M.11
47、.10.1 Amend clause M.11.10.1 as follows: M.11.10.1 Composition Options box The Composition Options box specifies parameters that apply to the composition or animation as a whole. The Composition Options box shall be the first box in the Composition box and a Composition Options box shall not be foun
48、d in any other location in the file. The type of the Composition Options box shall be copt (0x636F 7074) and contents of the box shall have the following format: T.801_FM-25HEIGHT WIDTHLOOPT.801_FM-25HEIGHT WIDTHLOOPFigure M.25 Organization of the contents of a Composition Options box HEIGHT: Render
49、ed result height. This field specifies the height, in samples, of the final rendered result. The resolution of this value is optionally defined in the Default Display Resolution box in the JP2 Header box. This field is encoded as a 4-byte unsigned integer. WIDTH: Rendered result width. This field specifies the width, in samples, of the final rendered result. The resolution of this value is optionally defined in the Default Display Resolution box in the JP2 Header box. This field is encoded as a 4-byte unsigned integer.
