YCbCr

YCbCr, Y′CbCr, or Y Pb/Cb Pr/Cr, also written as YC_BC_R or Y′C_BC_R, is a family of color spaces used as a part of the color image pipeline in digital video and photography systems.

Y′ is the luma component and C_B and C_R are the blue-difference and red-difference chroma components. Luma Y′ (with prime) is distinguished from luminance Y, meaning that light intensity is nonlinearly encoded based on gamma corrected RGB primaries.

Y′CbCr color spaces are defined by a mathematical coordinate transformation from an associated RGB primaries and white point. If the underlying RGB color space is absolute, the Y′CbCr color space is an absolute color space as well; conversely, if the RGB space is ill-defined, so is Y′CbCr. The transformation is defined in equations 32, 33 in ITU-T H.273.^[1]