Digital Signal Processing Handbook P55

Video sources produce data at very high bit rates. In many applications, the available bandwidth is usually very limited. For example, the bit rate produced by a 30 frame/s color common intermediate format (CIF) (352288) video source is 73 Mbits/s. In order to transmit such a sequence over a 64 Kbits/s channel (e.g., ISDNline), we need to compress the video sequence by a factor of 1140. A simple approach is to subsample the sequence in time and space. For example, if we subsample both chroma components by 2 in each dimension, i.e., 4:2:0 format, and the whole sequence temporally by 4, the bit rate becomes 9.1...