Multimedia compression is a general term referring to the compression
? of any type of
multimedia, most notably graphics, audio, and video.
Because multimedia typically derives from data sampled by a device such as a camera? or a microphone?, and because such data contains large amounts of random noise, traditional lossless compression algorithms tend to do a poor job compressing multimedia.
Multimedia compression algorithms, traditionally known as codecs, work in a lossy fashion:
- Transform the data according to a model designed to reduce sample-to-sample correlation, concentrating the important signal in a few data values.
- Quantize the data, most of which has become noise. Some codecs use a scalar quantizer followed by run-length encoding; others use [vector quantization]?.
- Use [entropy coding]? such as Huffman coding to reduce the number of bits that the most common values use.
Multimedia compression has become the primary focus of compression research, primarily in a search for more efficient models.