1、INTERNATIONALSTANDARDIEC61966-2-11999AMENDMENT 12003-01Amendment 1Multimedia systems and equipment Colour measurement and management Part 2-1:Colour management Default RGB colour space-sRGBAmendement 1Mesure et gestion de la couleur dans les systmeset appareils multimdia Partie 2-1:Gestion de la cou
2、leur Espace chromatique RVB par dfaut-sRVBPRICE CODE IEC 2003 Droits de reproduction rservs Copyright-all rights reservedInternational Electrotechnical Commission,3,rue de Varemb,PO Box 131,CH-1211 Geneva 20,SwitzerlandTelephone:+41 22 919 02 11 Telefax:+41 22 919 03 00 E-mail:inmailiec.ch Web:www.i
3、ec.chPFor price,see current catalogueLICENSED TO MECON Limited.-RANCHI/BANGALOREFOR INTERNAL USE AT THIS LOCATION ONLY,SUPPLIED BY BOOK SUPPLY BUREAU.2 61966-21 Amend.1 IEC:2003(E)FOREWORDThis amendment has been prepared by Technical Area 2:Colour measurement andmanagement,of IEC technical committee
4、 100:Audio,video and multimedia systemsand equipment and ISO TC 42:Photography.The text of this amendment is based on the following documents:FDISReport on voting100/555A/FDIS100/625/RVDFull information on the voting for the approval of this amendment can be found in the report onvoting indicated in
5、 the above table.It is published as a double logo standard.In the ISO the Standard has been approved by 10 P-members out of 10 having cast the vote._Page 5CONTENTSAdd the titles of Annexes F,G and H as follows:Annex F(normative)Default YCC encoding transformation for a standard luma-chroma-chroma co
6、lour space:sYCCAnnex G(informative)Extended gamut encoding for sRGB:bg-sRGB and its YCCtransformation:bg-sYCCAnnex H(informative)CIELAB(L*a*b*)transformationPage 49Add the following new Annexes F,G and H after Annex E:LICENSED TO MECON Limited.-RANCHI/BANGALOREFOR INTERNAL USE AT THIS LOCATION ONLY,
7、SUPPLIED BY BOOK SUPPLY BUREAU.61966-21 Amend.1 IEC:2003(E)3 Annex F(normative)Default YCC encoding transformation for astandard luma-chroma-chroma colour space:sYCCThe method of digitization in this annex is designed to complement current sRGB-based colourmanagement strategies by explicitly standar
8、dizing a default transformation between sRGB anda standard luma-chroma-chroma colour space(sYCC).Application and hardware developerswho want to support various colour compression schemes based on luma-chroma-chromaspaces can utilize this annex.Since this sYCC colour space is a simple extension of th
9、e sRGBcolour space as defined in this standard,the same reference conditions are shared by bothcolour spaces.F.1 GeneralThe encoding transformations between sYCC values and CIE 1931 XYZ values provideunambiguous methods to represent optimum image colorimetry when viewed on a hypotheticalreference di
10、splay that is capable of producing all colours defined by sYCC encoding,in thereference viewing conditions by the reference observer.Non-linear floating point sRGBrepresent the appearance of the image as displayed on the reference display in the referenceviewing condition described in Clause 4 of th
11、is standard.F.2 Transformation from sYCC values(sYCCsYCCsYCC,CrCbY)to CIE 1931 XYZvaluesThe non-linear sYCbCr values can be computed using the following relationship:()()()()RangeOffsetCrrCRangeOffsetCbbCKDCWDCKDCYY=sYCCsYCCsYCCsYCCsYCCsYCC(F.1)For 24-bit encoding(8-bit/channel),WDC=255,KDC=0,Range=
12、255,and Offset=128,andthe relationship is defined as;()()()()25512825512825502550=(8)(8)(8)(8)sYCCsYCCsYCCsYCCsYCCsYCCsYCCCrrCCbbCYYY(F.2)24-bit encoding(8-bit/channel)shall be the default sYCC encoding bit depth.Other bit depthsmay be unsupported for general use.Where other N-bit/channel encoding i
13、s supported(8N),the relationship is defined as;LICENSED TO MECON Limited.-RANCHI/BANGALOREFOR INTERNAL USE AT THIS LOCATION ONLY,SUPPLIED BY BOOK SUPPLY BUREAU.4 61966-21 Amend.1 IEC:2003(E)()()()()()1221221211=NNNNNCrrCCbbCYY(N)(N)(N)sYCCsYCCsYCCsYCCsYCCsYCC(F.2)For 24-bit encoding(8-bit/channel),t
14、he non-linear sYCbCr values are transformed to the non-linear sRGB values as follows;=sYCCsYCCsYCCsRGBsRGBsRGBrCbCY,BGR000000772100001171401344000001040210000000001(F.3)For N-bit/channel encoding(8N),it is recommended to replace the matrix coefficients in theequation F.3 with the coefficients of the
15、 inverse matrix of the equation F.12 with enoughaccuracy decimal points.For example,following matrix with 6 decimal points has enoughaccuracy for the case of 16-bit/channel.=sYCCsYCCsYCCsRGBsRGBsRGBrCbCY,BGR135000097877110000001104714011334400000001988401103700000000001(F.3)The non-linear sRGB value
16、s are then transformed to CIE 1931 XYZ values as follows:If 450400,BGRsRGBsRGBsRGB,()()()424242055105500551055005510550,sRGBsRGB,sRGBsRGB,sRGBsRGB,+=+=+=BBGGRR(F.6)LICENSED TO MECON Limited.-RANCHI/BANGALOREFOR INTERNAL USE AT THIS LOCATION ONLY,SUPPLIED BY BOOK SUPPLY BUREAU.61966-21 Amend.1 IEC:2003(E)5 For 24-bit encoding(8-bit/channel),the linear sRGB values are transformed to CIE 1931 XYZvalues as follows:=sRGBsRGBsRGBBGR,ZYX595002119030190207202715062120518006357044120(F.7)F.3 Transformati