IEC_61966-2-2-2003_cor1-2003.pdf

IEC 61966-2-2(First edition 2003)Multimedia systems and equipment Colour measurement and management Part 2-2 Colour management Extended RGB colour space-scRGBCORRIGENDUM 1Page 10Annex BReplace the existing Annex B,by the following:Annex B(informative)Non-linear encoding for scRGB:scRGB-nland its YCC Transformation:scYCC-nlB.1GeneralThis annex describes non-linear encoding for scRGB:scRGB-nl and its YCC transformation:scYCC-nl.Applications and hardware developers who want to support various colourcompression schemes based on luma-chroma-chroma spaces can utilise this standard.Thistransformation is targeted for compression and storage,and is not targeted for displayingimages.B.2Non-linear encoding in 12-bitThe relationship is defined as follows:If 81300030,scRGBscRGBscRGB,BGR()()()055,0055,1055,0055,1055005514,20,1scRGBscRGB4,20,1scRGBscRGB4,20,1scRGBscRGB=BBGG,R,R(B.1)If 8130003,0,81300030scRGBscRGBscRGBBGR,scRGBscRGBscRGBscRGBscRGBscRGB92,1292,129212BBGGR,R=(B.2)If 81300030,scRGBscRGBscRGB,BGR()()()()()()055,0055,1055,0055,1055,005514,20,14,20,14,20,1+=+=+=scRGBscRGBscRGBscRGBscRGBscRGBBBGGR,R(B.3)12 bit non-linear version of scRGB-nl:nl-scRGBnl-scRGBnl-scRGBB,G,R is defined as:()()()02412801round02412801round02412801roundscRGBnl-scRGBscRGBnl-scRGBscRGBnl-scRGB+=+=+=BBGGRR(B.4)For compression,scRGB-nl is converted to luma-chroma-chroma encoding:scYCC-nl.=scRGBscRGBscRGBscYCCscYCCscYCC30810741800500,00500,03331071680011400587002990BGR,rCbCY(B.5)And quantization for 12 bit non-linear scYCC-nl:nl-scYCCnl-scYCCnl-scYCCCr,Cb,Yis defined as:()()()04822801round04822801round02412801roundscYCCnl-scYCCscYCCnl-scYCCscYCCnl-scYCC+=+=+=rCCrbCCbYY(B.6)Note that this quantization leads to the following relationships,where a value of 65 535 inscRGB(16)is equivalent to 7,499 9 in scRGB and 4 080 in scRGB-nl.This is to easecomputational implementations.Table B.1 Quantization relationships using scRGBscRGB(16)scRGBscRGBscRGB-nlN/A0,603 80,800 0000,50,735 4832 0480,250,537 13374 09600,000 01 02412 28811,000 02 30420 48021,353 32 75628 67231,612 53 08836 86441,824 83 36045 05652,008 03 59453 24862,170 83 80361 44072,318 43 99265 5357,499 92,387 64 080N/A7,52,387 74 080N/A7,591 32,400 04 096Page 15Figure C.1 Example workflow using scRGBReplace,in the top line of Figure C.1,the words Output-referred colour,by the wordsOutput-referred colour space.August 2003