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