All luminance–chrominance formats used in the different TV and video standards such as YIQ for NTSC, YUV for PAL, YDBDR for SECAM, and YPBPR 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 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 format, a digital luminance–chrominance format based on YPBPR. The use of YCBCR also allows computers to perform lossy subsampling with the chrominance channels (typically to 4:2:2 or 4:1:1 ratios), which reduces the resultant file size.
