COMPRESSION TABLE

Comparison of Compression Tools
Compression
Tools		 "compress" "gzip" "jpeg"
Performance Compression
Rate		 Speed to
Compress
(byte/sec)		 Speed to
Uncompress
(byte/sec)		 Compression
Rate		 Speed to
Compress
(byte/sec)		 Speed to
Uncompress
(byte/sec)		 Compression
Rate		 Speed to
Compress
(byte/sec)		 Speed to
Uncompress
(byte/sec)
Image 1* 32.43% 156206.62 364888.91 39.10% 68107.01 829302.94 54.49% 115347.71 134539.35
Image 2* 30.30% 148814.94 339549.58 32.90% 67934.34 593293.22 50.63% 93624.32 134825.17
Image 3* 23.18% 110517.38 234849.44 37.70% 69381.94 740192.25 54.18% 118323.62 151862.54


Test on gzip compression utility with option of Best-on-Quality
Compression
Tools		 gzip
Performance Compression
Rate		 Speed to
Compress
(byte/sec)		 Speed to
Uncompress
(byte/sec)
Image 1* 39.50% 19667.67 825186.96
Image 2* 33.15% 20003.7 671967.63
Image 3* 38.14% 26274.39 788457.4



*Image1-14.40MB, Image2-16.22MB, Image3-15.92MB

This data comes from the results over the 42 Micron images with 16 bits per pixel on a Sun Sparc 20 workstation. Typical size of an uncompressed image is about 15MB. Timing was measured with the UNIX "usr/bin/time" utility, based on user time. Default settings were used for each compression tool. Our informal experience is that the option settings for the different tools do not produce major changes in the results.

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