COMPRESSION ALGORITHMS COMPARED
The following data compression algorithms were compared for
compression ratio and time for compression on a variety of raw
detector images from different scientific fields. This work was
carried out by Ulrike Willms.
- B.O. : The imgCIF / CBF Byte Offset algorithm
- B.O/pack : B.O. followed by pack
- B.O/gzip : B.O. folowed by gzip
- JPA : Jan Pieter Abraham's algorithm, which is
predictor 4, followed by variable length non-entropy encoding with a
variable number of bits
- pack : Huffman encoding
- compress : Lempel-Ziv dictionary encoding.
- gzip : Variation of LZ77 dictionary encoding.
- bzip : Runlength,
Burrow-Wheeler-Fenwick block sorting, move-to-front , and arithmetic
- bwt : As bzip, but the order of the operations may be
- ha 1 : Dictionary encoding followed by arithmetic
- ha 2 : Finite context model (sohisticated
predictor) followed by arithmetic encoding.
- ljpg : Variable predictor followed by Huffman
encoding (The JPEG standard also has an arithmetic encoding option.)
- btpc : Hierarchical image pyramid followed by
- shorten : More complicated predictor followed by
- freeze : Lemple-Ziv dictionary encoding, followed
by adaptive Huffman encoding.
- Pre Huff : Predictor 4 followed by modified
Huffman encoding using 256 codes.