2015年8月18日 星期二

YCbCr (Rec. 601) to YCbCr (Rec. 709)

http://www.avsforum.com/forum/25-hdtv-technical/1180698-conversion-matrix-ycbcr-rec-601-ycbcr-rec-709-a.html

On Page 320, "Digital Video and HDTV, Algorithms and Interfaces"

Y709 = Y601 + Cb601*(-0.11555) + Cr601*(-0.207938)
Cb709 = Cb601*(1.01864) + Cr601*(0.114618)
Cr709 = Cb601*(0.075049) + Cr601*(1.025327)

Y709 = (Y601 - 16) + ((Cb601 - 128)*(-0.11555)) + ((Cr601 - 128)*(-0.207938)) + 16
Cb709 = ((Cb601 - 128)*(1.01864)) + ((Cr601 - 128)*(0.114618)) + 128
Cr709 = ((Cb601 - 128)*(0.075049)) + ((Cr601 - 128)*(1.025327)) + 128

                         601 75% color bars
    white  yellow cyan  green  magenta  red  blue  black
Y    180    162    131   112      84     65    35    16
Cb   128     44    156    72     184    100   212   128
Cr   128    142     44    58     198    212   114   128

                         709 75% color bars
    white  yellow cyan  green  magenta  red  blue  black
Y    180    168    145   133      63     51    28    16
Cb   128     44    147    63     193    109   212   128
Cr   128    136     44    52     204    212   120   128

It turns out that there is a mistake in Eq 26.12 and Eq 26.13 in the original version of "Digital Video and HDTV, Algorithms and Interfaces". I've listed the correct coefficients
Also, the online version of "Digital Video and HDTV, Algorithms and Interfaces" has been corrected.


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