| Date |
Implementation |
Algorithm |
Author |
Ratio, bpc |
| 1977 |
LZ77 |
LZ |
Ziv, Lempel |
3.94 |
| 1984 |
LZW (GIF, V42/44b) |
LZ |
Welch |
3.27 |
| 1987 |
Deflate (PNG, gzip) |
LZ |
Katz |
2.63 |
| 1997 |
BOA |
PPM |
Sutton |
1.99 |
| 2000 |
RK |
PPM |
Taylor |
1.82 |
| 2002 |
SBC |
BWT |
Taylor |
1.88 |
|
Table 1
Lossless Compression Ratios for Text Compression on the Calgary Corpus
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