Y, Cr, Cb

The digital luminance and color difference signals in component video including ITU-R BT.601 (SD), ITU-R BT.709 (HD) ITU-R BT.2020 (UHD) coding. For SD with 4:2:2 sampling, the Y luminance signal is sampled at 13.5 MHz and the two color difference signals are sampled at 6.75 MHz co-sited with one of the luminance samples. Cr is the digitized version of the analog component (R-Y), likewise Cb is the digitized version of (B-Y). For BT.709 HD , sampling rates are 5.5 times greater – 74.25 MHz for Y and 37.125 MHz for Cr and Cb. Finally for BT.2020 4K UHD the frequencies are four times greater again at 297 and 128.5 MHz respectively for the luminance and chrominance.