Lossless Compression
Data is not lost - the original is really needed.
- text compression
- compression of computer binaries to fit on a floppy
Compression ratio typically no better than 4:1 for lossless compression.
Major techniques include
- Huffman coding
- Arithmetic coding
- Dictionary techniques (Ziv,Lempel 1977,1978)
- Sequitur (Nevill-Manning, Witten 1996)
- Standards - Morse code, Braille, Unix compress, gzip, zip, GIF, JBIG, JPEG