shared_space [osirion] compression

skybox compression format comparison (180 * 1024x1024 pictures)
corpus: tex-space_src.pk3dir/textures/shared_space_src
adapted from http://ingar.satgnu.net/files/unvanquished/env-osirion-r02-src.zip (some files rotated for Unvanquished needs)
____________________________________________________________________________________________________

=== directory ===

+ format     tool     options
- highbpg    bpgenc   -e jctvc -m 9
- lossybpg   bpgenc
- bpg        bpgenc   -e jctvc -m 9 -lossless
- highwebp   cwebp    -q 92 -pass 10
- lossywebp  cwebp
- webp       cwebp    -lossless
- highjpg    convert  -quality 92
- lossyjpg   convert
- zopflipng  pngwolf  --out-deflate=zopfli,iter=30 --max-stagnate-time=20
- optipng    optipng  -strip all
- png        convert  +set comment -define pngexclude-chunks=date
- flif       flif     -E100

2,8M  shared_space_src.highbpg    (lossy, bad)
2,8M  shared_space_src.lossybpg   (lossy, bad)
4,8M  shared_space_src.lossywebp  (lossy, ugly)
12M   shared_space_src.highwebp   (lossy, good)
23M   shared_space_src.jpg        (lossy, ugly)
28M   shared_space_src.highjpg    (lossy, ugly)
29M   shared_space_src.highcrn    ((lossy, good)
37M   shared_space_src.crn        (lossy, good)
67M   shared_space_src.flif       (lossless)
76M   shared_space_src.bpg        (lossless)
80M   shared_space_src.webp       (lossless)
89M   shared_space_src.zopflipng  (lossless)
99M   shared_space_src.optipng    (lossless)
105M  shared_space_src.png        (lossless)
541M  shared_space_src.tga        (lossless)

=== per archives ===

+ format     tool     options
- tar        tar      -cf
- zip        7z       -mx=9
- 7z         7z       -m0=lzma -mx=9 -mfb=64 -md=32m

2,9M  shared_space_src.highbpg.tar
2,9M  shared_space_src.lossybpg.tar
4,9M  shared_space_src.lossywebp.tar
12M   shared_space_src.highwebp.tar
23M   shared_space_src.jpg.tar
28M   shared_space_src.highjpg.tar
30M   shared_space_src.highcrn.tar
37M   shared_space_src.crn.tar
68M   shared_space_src.flif.tar
76M   shared_space_src.bpg.tar
80M   shared_space_src.webp.tar
89M   shared_space_src.zopflipng.tar
99M   shared_space_src.optipng.tar
105M  shared_space_src.png.tar
541M  shared_space_src.tga.tar

2,8M  shared_space_src.highbpg.zip
2,8M  shared_space_src.lossybpg.zip
4,8M  shared_space_src.lossywebp.zip
12M   shared_space_src.highwebp.zip
22M   shared_space_src.jpg.zip
28M   shared_space_src.highjpg.zip
29M   shared_space_src.highcrn.zip
37M   shared_space_src.crn.zip
67M   shared_space_src.flif.zip
76M   shared_space_src.bpg.zip
79M   shared_space_src.webp.zip
89M   shared_space_src.zopflipng.zip
97M   shared_space_src.optipng.zip
105M  shared_space_src.png.zip
117M  shared_space_src.tga.zip
763M  total

2,8M  shared_space_src.highbpg.7z
2,8M  shared_space_src.lossybpg.7z
4,9M  shared_space_src.lossywebp.7z
12M   shared_space_src.highwebp.7z
21M   shared_space_src.jpg.7z
26M   shared_space_src.highjpg.7z
30M   shared_space_src.highcrn.7z
37M   shared_space_src.crn.7z
68M   shared_space_src.flif.7z
77M   shared_space_src.bpg.7z
79M   shared_space_src.webp.7z
90M   shared_space_src.tga.7z
90M   shared_space_src.zopflipng.7z
97M   shared_space_src.optipng.7z
106M  shared_space_src.png.7z
737M  total

=== all archives ===

- notices that in some time an uncompressed tar is smaller than a zip archive due to format overhead greater than compression

2,8M  shared_space_src.highbpg.7z
2,8M  shared_space_src.highbpg.zip
2,8M  shared_space_src.lossybpg.7z
2,8M  shared_space_src.lossybpg.zip
2,9M  shared_space_src.highbpg.tar
2,9M  shared_space_src.lossybpg.tar
4,8M  shared_space_src.lossywebp.zip
4,9M  shared_space_src.lossywebp.7z
4,9M  shared_space_src.lossywebp.tar
12M   shared_space_src.highwebp.7z
12M   shared_space_src.highwebp.tar
12M   shared_space_src.highwebp.zip
21M   shared_space_src.jpg.7z
22M   shared_space_src.jpg.zip
23M   shared_space_src.jpg.tar
26M   shared_space_src.highjpg.7z
28M   shared_space_src.highjpg.tar
28M   shared_space_src.highjpg.zip
29M   shared_space_src.highcrn.zip
30M   shared_space_src.highcrn.7z
30M   shared_space_src.highcrn.tar
37M   shared_space_src.crn.7z
37M   shared_space_src.crn.tar
37M   shared_space_src.crn.zip
67M   shared_space_src.flif.zip
68M   shared_space_src.flif.7z
68M   shared_space_src.flif.tar
76M   shared_space_src.bpg.tar
76M   shared_space_src.bpg.zip
77M   shared_space_src.bpg.7z
79M   shared_space_src.webp.7z
79M   shared_space_src.webp.zip
80M   shared_space_src.webp.tar
89M   shared_space_src.zopflipng.tar
89M   shared_space_src.zopflipng.zip
90M   shared_space_src.tga.7z
90M   shared_space_src.zopflipng.7z
97M   shared_space_src.optipng.7z
97M   shared_space_src.optipng.zip
99M   shared_space_src.optipng.tar
105M  shared_space_src.png.tar
105M  shared_space_src.png.zip
106M  shared_space_src.png.7z
117M  shared_space_src.tga.zip
541M  shared_space_src.tga.tar