Editing RGB color model (section)

==RGB model and luminance–chrominance formats relationship==
All [[relative luminance|luminance]]–chrominance formats used in the different TV and video standards such as [[YIQ]] for [[NTSC]], [[YUV]] for [[PAL]], [[YDbDr|YD<sub>B</sub>D<sub>R</sub>]] for [[SECAM]], and [[YPbPr|YP<sub>B</sub>P<sub>R</sub>]] for component video use color difference signals, by which RGB color images can be encoded for broadcasting/recording and later decoded into RGB again to display them. These intermediate formats were needed for compatibility with pre-existent black-and-white TV formats. Also, those color difference signals need lower data [[Bandwidth (signal processing)|bandwidth]] compared to full RGB signals.

Similarly, current high-efficiency digital color image [[data compression]] schemes such as [[JPEG]] and [[MPEG]] store RGB color internally in [[YCbCr|YC<sub>B</sub>C<sub>R</sub>]] format, a digital luminance–chrominance format based on YP<sub>B</sub>P<sub>R</sub>. The use of YC<sub>B</sub>C<sub>R</sub> also allows computers to perform [[Lossy compression|lossy]] [[Chroma subsampling|subsampling]] with the chrominance channels (typically to 4:2:2 or 4:1:1 ratios), which reduces the resultant file size.