Y=krR+(1-kb-kr)G+kbB
Cb=0.5/(1-kb)*(B-Y)
Cr=0.5/(1-kr)*(R-Y)

ITU-R的BT.601决议定义了kb=0.114,kr=0.299，那么代换参数就有了如下等式：

Y=0.299R+0.587G+0.114B
Cb=0.564(B-Y)
Cr=0.713(R-Y)
同理Cg=0.5/(1-kg)*(G-Y)
=0.5/(kb+kr)*(G-Y)
=1.211(G-Y)

R=Y+1.402Cr
G=Y-0.344Cb-0.714Cr

B=Y+1.772Cb