Video sources produce data at very high bit rates. In many applications, the available bandwidth is usually very limited. | Osama Al-Shaykh et. Al. Video Sequence Compression. 2000 CRC Press LLC. http . Video Sequence Compression Osama Al-Shaykh University of California Berkeley Ralph Neff University of California Berkeley David Taubman Hewlett Packard Avideh Zakhor University of California Berkeley Introduction Motion Compensated Video Coding Motion Estimation and Compensation Transformations Discussion Quantization Coding of Quantized Symbols Desirable Features Scalability Error Resilience Standards MPEG-1 MPEG-2 MPEG-4 Acknowledgment References The image and video processing literature is rich with video compression algorithms. This chapter overviews the basic blocks of most video compression systems discusses some important features required by many applications . scalability and error resilience and reviews the existing video compression standards such as MPEG-1 MPEG-2 and MPEG-4. Introduction 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 352 x 288 video source is 73 Mbits s. In order to transmit such a sequence over a 64 Kbits s channel . ISDN line 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 . 4 2 0 format and the whole sequence temporally by 4 the bit rate becomes Mbits s. However to transmit the video over a 64 kbits s channel it is necessary to compress the subsampled sequence by another factor of 143. To achieve such high compression ratios we must tolerate some distortion in the subsampled frames. Compression can be either lossless reversible or lossy irreversible . A compression algorithm is lossless if the signal can be reconstructed from the compressed information otherwise it is .
