Y, Cr, Cb The digital luminance and color difference signals in ITU-R BT.601 coding. The Y luminance signal is sampled at l3.5 MHz and the two color difference signals are sampled at 6.75 MHz co-sited with one of the luminance samples. Cris the digitized version of the analog component (R- Y), likewise Cb is the digitized version of (B-Y). For the HD SMPTE 274M standard, sampling rates are 5.5 times greater - 74.25 MHz for Y and 37.125 MHz for Cr and Cb.
Y, R-Y, B-Y These are the analog luminance, Y, and color difference signals (R-Y) and (B-Y) of component video. Y is pure luminance information whilst the two color difference signals together provide the color information. The latter are the difference between a color and luminance: red - luminance and blue - luminance. The signals are derived from the original RGB source (e.g. a camera or telecine). The Y, (R-Y), (B-Y) signals are fundamental to much of television. For example in ITU-R BT.601 it is these signals that are digitized to make 4:2:2 component digital video, in the PAL and NTSC TV systems they are used to generate the final composite coded signal and in DTV they are sampled to create the MPEG-2 video bitstream. See also: 4:2:2, Luminance, NTSC, Y,Cr,Cb, YUV
YUV Convenient shorthand commonly - but incorrectly - used to describe the analog luminance and color difference signals in component video systems. Y is correct for luminance but U and V are, in fact, the two subcarrier modulation axes used in the PAL color coding system. Scaled and filtered versions of the B-Y and R-Y color difference signals are used to modulate the PAL subcarrier in the U and V axes respectively. See also: PAL