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SMPTE-C RGB

SMPTE-C is the current colour standard for broadcasting in America, the old NTSC standard for primaries is no longer in wide use because the primaries of the system have gradually shifted towards those of the EBU (see section 6.2). In all other respects, SMPTE-C is the same as NTSC. The CRT gamma law is assumed to be 2.2. The white point is now D65, and the chromaticities are:

    R:     xr=0.630     yr=0.340
    G:     xg=0.310     yg=0.595
    B:     xb=0.155     yb=0.070
    White: xn=0.312713  yn=0.329016
The conversion equations for linear signals are:

    X = 0.3935*R + 0.3653*G + 0.1916*B
    Y = 0.2124*R + 0.7011*G + 0.0866*B
    Z = 0.0187*R + 0.1119*G + 0.9582*B

    R = 3.5058*X - 1.7397*Y - 0.5440*Z
    G =-1.0690*X + 1.9778*Y + 0.0352*Z
    B = 0.0563*X - 0.1970*Y + 1.0501*Z

The coding equations for non-linear signals are the same as for NTSC:

    Y'= 0.299*R' + 0.587*G' + 0.114*B'
    I'=-0.27*(B' - Y') + 0.74*(R' - Y') = 0.596*R' - 0.274*G' + 0.322*B'
    Q'= 0.41*(B' - Y') + 0.48*(R' - Y') = 0.212*R' - 0.523*G' - 0.311*B'

    R'= Y' + 0.956*I' + 0.621*Q'
    G'= Y' - 0.272*I' - 0.647*Q'
    B'= Y' - 1.105*I' + 1.702*Q'

and the same conversion equations work between EBU and SMPTE-C components:

    I'=-0.547*U' + 0.843*V'
    Q'= 0.831*U' + 0.547*V'
    U'=-0.547*I' + 0.843*Q'
    V'= 0.831*I' + 0.547*Q'
The conversion equations relating SMPTE-C RGB signals to EBU and 709 signals are:

    Rsmptec= 1.1123*Rebu - 0.1024*Gebu - 0.0099*Bebu
    Gsmptec=-0.0205*Rebu + 1.0370*Gebu - 0.0165*Bebu
    Bsmptec= 0.0017*Rebu + 0.0161*Gebu + 0.9822*Bebu
    Rebu= 0.9007*Rsmptec + 0.0888*Gsmptec + 0.0105*Bsmptec
    Gebu= 0.0178*Rsmptec + 0.9658*Gsmptec + 0.0164*Bsmptec
    Bebu=-0.0019*Rsmptec - 0.0160*Gsmptec + 1.0178*Bsmptec
and:

    Rsmptec= 1.0654*R709 - 0.0554*G709 - 0.0010*B709
    Gsmptec=-0.0196*R709 + 1.0364*G709 - 0.0167*B709
    Bsmptec= 0.0016*R709 + 0.0044*G709 + 0.9940*B709

    R709= 0.9395*Rsmptec + 0.0502*Gsmptec + 0.0103*Bsmptec
    G709= 0.0178*Rsmptec + 0.9658*Gsmptec + 0.0164*Bsmptec
    B709=-0.0016*Rsmptec - 0.0044*Gsmptec + 1.0060*Bsmptec