1、BRITISH STANDARDBS EN 61966-2-4:2006Multimedia systems and equipment Colour measurement and management Part 24: Colour management Extended-gamut YCC colour space for video applications xvYCCICS 33.160.40; 17.180.20 nullnull nullnullnullnullnullnullnull nullnullnullnullnullnullnull nullnullnull nulln
2、ullnullnullnullnullnullnullnullnull nullnullnullnullnullnull nullnull nullnullnullnullnullnullnullnullnull nullnull nullnullnullnullnullnullnullnullnull nullnullnull+A1:2016(IEC 61966-2-4:2006)BS EN 61966-2-4:2006+A1:2016This British Standard was published under the authority of the Standards Policy
3、 and Strategy Committeeon 31 October 2006ISBN 978 0 580 90117 1National forewordThis British Standardis the UK implementation of EN 61966-2-4:2006+A1:2016. It supersedes BS EN 61966-2-4:2006 whichThe UK participation in its preparation was entrusted to Technical Committee EPL/100, Audio, video and m
4、ultimedia systems and equipment.This publication does not purport to include all the necessary provisionsof a contract. Users are responsible for its correct application.Compliance with a British Standardcannot confer immunity from legal obligations.The start and finish of text introduced or altered
5、 by amendment is indicated in the text by tags. Tags indicating changes to IEC text carry the number of the IEC amendment. For example, text altered by IEC amendment 1 is indicated by .!“ The British StandardsInstitution 2016. Published byBSI Standards Limited 2016Amendments/corrigenda issued since
6、publicationDate Comments 31 October 2016 Implementation of IEC amendment 1:2016 with CENELEC endorsement A1:2016 is withdrawn. A list of organizations represented on this committee can be obtained on request to its secretary.EUROPEAN STANDARD EN 61966-2-4:2006+A1NORME EUROPENNE EUROPISCHE NORM Septe
7、mber 2016 CENELEC European Committee forElectrotechnicalStandardizationComit Europen deNormalisation Electrotechnique EuropischesKomitee fr Elektrotechnische Normung Central Secretariat:rue de Stassart35, B - 1050 Brussels 2006 CENELEC - All rights of exploitation in any form and by any means reserv
8、ed worldwide for CENELECmembers.Ref. No. EN 61966-2-4:2006 EICS 33.160.40 English version Multimedia systems and equipment - Colour measurement and management Part 2-4: Colourmanagement - Extended-gamut YCC colour space for video applications - xvYCC (IEC 61966-2-4:2006)Mesure et gestion de la coule
9、urdans les systmes et appareilsmultimediaPartie 2-4 : Gestion de la couleur -Extension de gamme de lespace chromatique YCC pourapplications vido -xvYCC (CEI 61966-2-4:2006)Multimediasysteme und -gerte -Farbmessung und Farbmanagement Teil 2-4: Farbmanagement -Erweiterter YCC-Farbraumfr Videoanwendung
10、en -xvYCC (IEC 61966-2-4:2006)This European Standard was approved by CENELEC on 2006-09-01. CENELEC members are bound to complywith the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this European Standard the status of a national standard without any alteration. Up-to-da
11、te lists and bibliographical references concerning such national standards may be obtained onapplication to the Central Secretariat or to any CENELEC member. This European Standard exists in two official versions (English and German). A version in any other languagemade by translation under the resp
12、onsibility of a CENELECmember into its own language and notified to the Central Secretariat has the same status as the official versions. CENELEC members are the national electrotechnical committees of Austria, Belgium, Cyprus, the Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece,
13、Hungary, Iceland, Ireland, Italy, Latvia,Lithuania, Luxembourg, Malta, the Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland and the United Kingdom. Foreword The text of the International Standard IEC 61966-2-4:2006, prepared by IEC TC100, Audio, video an
14、dmultimedia systems and equipment, was submitted to the formal vote and was approved byCENELEC asEN 61966-2-4 on 2006-09-01 without any modification. The following dates were fixed: latest date by which the EN hasto be implemented at national level bypublication of an identical national standard or
15、by endorsement (dop) 2007-06-01 latestdate bywhich the national s tandards conflictingwith the EN have to be withdrawn (dow) 2009-09-01 _ Endorsement noticeThe text of the International Standard IEC 61966-2-4:2006 was approved by CENELEC as a European Standard without any modification. In the offici
16、al version, for Bibliography, the following notes have to be added for the standards indicated: IEC 61966-2-1 + A1NOTE Harmonized as EN 61966-2-1:2000 + A1:2003 (notmodified).IEC 61966-2-2 NOTE Harmonized as EN 61966-2-2:2003 (notmodified)._ 2 EN 61966-2-4:2006+A1:2016Foreword to amendment A1The tex
17、t of document 100/2457A/CDV, future IEC 61966-2-4:2006/A1, prepared by IEC/TC 100, “Audio, video and multimedia systems and equipment“ was submitted to the IEC-CENELEC parallel vote and approved by CENELEC as EN 61966-2-4:2006/A1:2016. The following dates are fixed: latest date by which the document
18、 has to be implemented at national level by publication of an identical national standard or by endorsement (dop) 2017-03-02 latest date by which the national standards conflicting with the document have to be withdrawn (dow) 2019-06-02 Attention is drawn to the possibility that some of the elements
19、 of this document may be the subject of patent rights. CENELEC and/or CEN shall not be held responsible for identifying any or all such patent rights. Endorsement notice The text of the International Standard IEC 61966-2-4:2006/A1:2016 was approved by CENELEC as a European Standard without any modif
20、ication. In the official version, for Bibliography, the following notes have to be added for the standards indicated: Addition IEC 61633-12-1:2011 NOTE Harmonized as EN 61633-12-1:2011. IEC 61633-12-2:2014 NOTE Harmonized as EN 61633-12-2:2014. BS EN 61966-2-4:2006+A1:2016Annex ZA(normative)Normativ
21、e references to i nternational publica tions with their c orresponding European publications The following referenced documents are indisp ensable for the application of this document. For dated references, only the edition cited applies . For undated references, the latest edition of the r eference
22、ddocument (including anyamendments) applies.NOTE Where an international publication has been modified by common modifications, indicated by (mod), the relevant EN/HD applies.Publication Year Title EN/HD YearIEC 60050-845 1987 International Electrotechnical Vocabulary(IEV)Chapter 845: Lighting - -ITU
23、-R Recommendation BT.601-51995 Studio encoding parameters of digital television forstandard 4:3 and wide-screen 16:9 aspect ratios- -ITU-R Recommendation BT.709-52002 Parameter values for theHDTV standardsfor production and international programme exchange - - 3 BS EN 61966-2-4:2006+A1:2016EN 61966-
24、2-4:2006+A1:2016CONTENTSINTRODUCTION.51 Scope.62 Normative references.63 Terms and definitions.64 Colorimetric parameters and related characteristics.74.1 Primary colours and reference white74.2 Opto-electronic transfer characteristics.74.3 YCC (luma-chroma-chroma) encoding methods.84.4 Digital quan
25、tization methods .85 Encoding transformations.95.1 Introduction.95.2 Transformation from xvYCC values to CIE 1931 XYZ values.95.3 Transformation from CIE 1931 XYZ values to xvYCC values.11Annex A (informative) Compression of specular components of Y signals.13Annex B (informative) Default transforma
26、tion from 16-bit scRGB values to xvYCC values14Annex C (informative) xvYCC/ITU-R BT.709 and sYCC/sRGB compatibility.16Bibliography19Figure A.1 Example of the specular compression method15Figure C.1 Relationship between ITU-R BT.709 and sRGB16Figure C.2 Relationship between xvYCC and sYCC.17Table 1 C
27、IE chromaticities for reference primary colours and reference white7. 4 Annex ZA (normative) Normative references to international publications with theircorresponding European publications.BS EN 61966-2-4:2006+A1:2016Recommended usage of IEC 61966-12-2 for this standard .18 Annex D (informative)IEC
28、 61966-2-4:2006+A1:201620INTRODUCTION After the publicationof IEC61966-2-1, Amendment 1,the sYCCcolour encoding was usedto capture, store and print ext ended colourgamut forst ill image applications. Users received pleasant benefit by exchanging and reproducing wide-gamutcolour images.Recently, vari
29、ous kinds of displays that are capable of producing a wider gamut of colour thanthe conventional CRT-based displays are emerging. However, most of the current video contents that are displayed on conventional displays, are rendered for the sRGB-gamut. Users of wide-gamut displays c ould benefit from
30、 wide-gamut c olour images by video colourencoding that supports a largercolour gamut. This standard defines the “extended-gamut YCC colour space for video applications”. Itisbased on thecurrent implementation of YCC colour encoding that isused in the video industry(namely ITU-R BT.709-5) and extend
31、s its definition to the wider gamut ofcolour range. 5 BS EN 61966-2-4:2006+A1:2016IEC 61966-2-4:2006+A1:2016MULTIMEDIA SYSTEMS AND EQUIPMENT COLOUR MEASUREMENT A ND MANAGEMENT Part 2-4: Colour management Extended-gamut YCC colour space for video applications xvYCC 1 Scope This part of IEC 61966 is a
32、pplicable to the encoding and communication of YCC coloursusedin video systems and similar applications by defining encoding transformations for use indefined reference capturing conditions. If actual conditions differ from the reference conditions,additional rendering transformations may be require
33、d. Such additional rendering trans-formations are beyond the scope ofthis standard. 2 Normative referencesThe following referenced documents are indispensable for the application of this document.For dated references, only the edition cited applies. For undated r eferences, thelatesteditionof the re
34、ferenced document (including anyamendments)applies.IEC 60050-845:1987, International Electrotechnical Vocabulary (IEV) Part 845: LightingITU-R Recommendation BT.601-5:1995, Studio encodingparameters of digital television forstandard4:3 and wide-screen 16:9 aspect ratiosITU-R Recommendation BT.709-5:
35、2002, Parameter values for the HDTV standards for production and internationalprogramme exchange3 Terms and definitionsFor the purposesof this document,the following terms and definitions, as well as those concerning illuminance, luminance, tristimulus, and other related lighting terms given inIEC 6
36、0050-845, apply.3.1scene-referred colour encodingrepresentation ofestimated colour-space coordinates of the elements of an original scene,where ascene is defined to be therelative spectral radiance3.2output-referred colour encoding representation of estimated colour-space coordinatesofimage data tha
37、t are appropriate forspecified outputdevice and viewing conditions3.3extended gamutcolour gamut extending outside that of the standard sRGB CRT displaydefined in IEC 61966-2-1 6 BS EN 61966-2-4:2006+A1:2016IEC 61966-2-4:2006+A1:20163.4lumaluminance signal asdefined by SMPTE/EG28:1993 NOTE 1 To avoid
38、 interdisciplinary confusion resulting from the two distinct definitions of luminance, it has beenproposed that the video documents use “luma” for “luminance, television” (i.e., the luminance signal).NOTE 2 Video systems approximate the lightness response of vision by computing a luma component Y as
39、 aweighted sum of non-linear (or gamma-corrected) RGB primary components. Luma is often carelessly referred to as luminance.4 Colorimetric parameters and related characteristics This clause defines colorimetric parametersand the related characteristicsof reference capturing devices. 4.1Primary colou
40、rs and reference white The CIEchromaticities forthe reference red, green, and blue primary colours,and forreference white CIE standard illuminant D65, are given inTable 1. These primaries and whitepoint values are identicalto those of ITU-R BT.709-5. Table 1 CIEchromaticitiesfor referen ce primary c
41、olours and reference white Red Green Blue White/D65 x 0,640 0 0,300 0 0,150 0 0,312 7 y 0,330 0 0,600 0 0,060 0 0,329 0 z 0,030 0 0,100 0 0,790 0 0,358 3 4.2 Opto-electronic transfer characteristics Opto-electronic transfer characteristics are defined as follows.If 0180, ,BGR , ()()() 099,0099,1099,
42、0099,1099,0099,145,045,045,0+=+=+=BBGGRR(1) If 0180,0180 ,BGR, 8) representation: () ()8)(xvYCC8)(xvYCC8)(xvYCC2128224round2128224round216219round+=+=+=nNnNnNrCCrbCCbYY(7) NOTE Bit levels “from 0 to 2 N-8 -1” and “from254 x 2 N-8 + 1 to 2N -1” (0 and 255, in the case of 8-bit encoding)areused exclus
43、ively for synchronization and are not allowed for storing colour values.Levels from “2 N-8 ” to “254x 2N-8 ” (from 1 to 254, in the case of 8-bit encoding) are available. 8 BS EN 61966-2-4:2006+A1:2016IEC 61966-2-4:2006+A1:20165 Encoding transformations 5.1 Introduction The encoding transformations
44、between xvYCC valuesand CIE 1931 XYZ values provideunambiguous methods to represent optimum image colorimetry of the captured scene. Scenecolorimetry is defined as relative to the white objects, assuming that the exposure is properlycontrolled. It shouldbenoted that dynamic range compression isneede
45、d when storing the wide dynamic range images (seeAnnex A for descriptions). Additionally, if the condition of the capturing device deviates fromthe ideal condition defined in Clause 4, operationssuchascolour compensation, colour correction and a certain degree of colour rendering can beperformed. Ho
46、wever, the methods for these operations are beyond the scope of this standard. 5.2 Transformation fromxvYCC values to CIE 1931 XYZ valuesFor 24-bit encoding (8-bit/channel), the relationship between 8-bit valuesand rCbCY , isdefined as: ( )()22412822412821916)8(xvYCC)8(xvYCC)8(xvYCC=CrrCCbbCYY(8) Fo
47、r N -bit/channel ( 8N )encoding, the relationship between N-bit valuesand rCbCY , is defined as:224128222412822191628)(xvYCC8)(xvYCC8)(xvYCC = = =NNNNNNCrrCCbbCYY(9) For xvYCC 601 encoding, the non-linear rCbCY , values are transformed to the non-linearBGR , values asfollows:=60160160100000077210000
48、1171401344000001040210000000001rCbCY,BGR(10) NOTEThe possible range for non-linear RGB(601) calculated from, for example, equation (10) will be between-1,0732 and 2,0835.For xvYCC 709 encoding, the non-linear rCbCY , values are transformed to the non-linearBGR , values asfollows:=709709709000006855100001146803187000001857410000000001rCbCY,BGR(11) NOTE The possible range for non-linear RGB(709) calculated from, for example, equation (11) will be between-1,1206 and 2,1305. 9 BS EN 61966-2-4:2006+A1:2016IEC 61966-2-4:2006+A1:2016The non-linear BGR , values are then transformed to linear BGR , va
