been running some more test on the webcomic Lookin for group
they are gif on the website and then converted to png with paint shop pro 7.04 as source files.
same png batch files as above (best and fast) and i put in a new version that only does filter 0 with the most used block threshold to reduce pngout time to absolute minimum to get some results as the full set of trials. it was to give pngout a kind of best case time wise when comparing against pngwolf.
384 512 768 was the 3 most used and i added in 1024 just in case, and as the filter trial is always done with the default 256 blocks tressholds the entire F0 run is only 5 tpngout trials (3 optimal +the default 256 and the extra 1024).
i also in the double encoding tried to run a with the -f6 filter options with the same tress hold as mentioned above
so to recap
PNGout best = 5 runs of filters options 0-5, then running through all the thresholds.
PNGout fast = 5 runs of filters options 0-5, then ruining through a reduced set of thresholds.
PNGout /f0 = 1 run of filter /f0, then 4 specific optimal chosen thresholds.
pngout /f6 = 1 run of filter /f6, then 4 specific optimal chosen thresholds.
it looks like pngwolf just does not like to work with palleted images and pngout does a great job here.
Album1 32 files 10,8 MB (11.415.637 bytes)
PNGwolf 10,3 MB (10.855.255 bytes) Global Time = 477.410 = 00:07:57.410 = 100%
Pngout Best 10,3 MB (10.813.178 bytes) Global Time = 3324.194 = 00:55:24.194 = 100%
PNGout fast 10,3 MB (10.814.909 bytes) Global Time = 1249.896 = 00:20:49.896 = 100% 31 files differ from best
PNGwolf > PNGout 10,3 MB (10.813.117 bytes) Global Time = 3307.377 = 00:55:07.377 = 100% All files improved over pngwolf
PNGout > PNGwolf 10,3 MB (10.813.178 bytes) Global Time = 450.032 = 00:07:30.032 = 100% No files improved over PNGout
PNGwolf > DeflOpt 10,3 MB (10.852.117 bytes) 32 files rewritten
PNGout > DeflOpt 10,3 MB (10.811.387 bytes) 32 files rewritten
Album2 28 files 9,28 MB (9.732.563 bytes)
PNGwolf 8,82 MB (9.255.398 bytes) Global Time = 431.608 = 00:07:11.608 = 100%
PNGout Best 8,78 MB (9.215.928 bytes) Global Time = 3179.893 = 00:52:59.893 = 100%
PNGout /f0 8,78 MB (9.215.928 bytes) Global Time = 552.353 = 00:09:12.353 = 100%
PNGwolf > PNGout /f0 8,78 MB (9.215.919 bytes) Global Time = 716.497 = 00:11:56.497 = 100%
PNGwolf > PNGout /f6 8,79 MB (9.218.784 bytes) Global Time = 685.125 = 00:11:25.125 = 100%
PNGout > PNGwolf 8,78 MB (9.215.928 bytes) Global Time = 409.503 = 00:06:49.503 = 100% No files changes compared to pngout (md5 verified ok)
PNGwolf > DeflOpt 8,82 MB (9.252.635 bytes) 28/28 files rewritten
PNGout > Deflopt 8,78 MB (9.214.357 bytes) 28/28 files rewritten
Album 3 28 files 9,20 MB (9.655.236 bytes)
PNGwolf 8,76 MB (9.188.725 bytes) Global Time = 537.330 = 00:08:57.330 = 100%
PNGout 8,73 MB (9.155.424 bytes) Global Time = 4530.332 = 01:15:30.332 = 100%
PNGout f0 8,73 MB (9.155.424 bytes) Global Time = 937.020 = 00:15:37.020 = 100% all files identical to full run (md5 verified)
PNGwolf > PNGout 8,73 MB (9.155.444 bytes) Global Time = 3815.613 = 01:03:35.613 = 100%
PNGout > PNGwolf 8,73 MB (9.155.424 bytes) Global Time = 467.504 = 00:07:47.504 = 100% no files improved (md5 identical to first pass)
PNGwolf > DeflOpt 8,75 MB (9.185.977 bytes)
PNGout > DeflOpt 8,72 MB (9.154.049 bytes)
Album4 28 files 8,56 MB (8.978.108 bytes)
PNGwolf 8,13 MB (8.528.131 bytes) Global Time = 424.448 = 00:07:04.448 = 100%
PNGout 8,10 MB (8.496.164 bytes) Global Time = 3450.384 = 00:57:30.384 = 100%
PNGout F0 8,10 MB (8.496.164 bytes) Global Time = 792.610 = 00:13:12.610 = 100% all files identical to full pngout (md5 verified)
PNGwolf > PNGout 8,10 MB (8.496.158 bytes)
PNGout > PNGwolf 8,10 MB (8.496.164 bytes) No files improved in second pass (md5 verified)
PNGwolf > DeflOpt 8,12 MB (8.525.440 bytes) all files rewritten
PNGout > DeflOpt 8,10 MB (8.494.869 bytes) all files rewritten
Album5 28 files 9,06 MB (9.504.134 bytes)
PNGwolf 8,61 MB (9.036.326 bytes) Global Time = 472.839 = 00:07:52.839 = 100%
PNGout 8,58 MB (9.002.837 bytes) Global Time = 3423.520 = 00:57:03.520 = 100%
PNGout F0 8,58 MB (9.002.837 bytes) Global Time = 1044.037 = 00:17:24.037 = 100% all files identical to full pngout run (md5 verified)
PNGwolf > PNGout 8,58 MB (9.002.899 bytes) Global Time = 3796.019 = 01:03:16.019 = 100%
PNGout > PNGwolf 8,58 MB (9.002.837 bytes) Global Time = 462.481 = 00:07:42.481 = 100% No files improved over pngtout (md5 verified)
PNGwolf > DeflOpt 8,61 MB (9.033.552 bytes) all files rewritten
Pngout > DeflOpt 8,58 MB (9.001.571 bytes) all files rewritten
pngout might not be alot better than pngwolf buts its constantly better on this kind of images (255 colors none dither cartoon images)
i dig'ed into some weird behavior and i found out that pngout seems to choses different pallets depending on thresholded and the coding of a picture.
rerunning pngout on the same file over and over with the same threshold got the same new palette. hover Channing the threshold gave another palette.
doing the same input picture but with a different encoding the palette would once again change.
so to recap both encoding block treshold and how the input pictures is encoded has a affect on how pngout choses the pallet to be used (even thought its the same pictures
also it seams that linear run through different block thresholds makes a u shaped graph of the finish size which opens up the possibility for making a smart choice on block threshold instead of relying on brute force. basically with just 2 different but "close" block thresholds we can know what way to go until the final size increase again and the previous encoding would be optimal.
this way we can cut out at least half the encoding compare to brute forcing.
well i got tired of doing one album at a time since the results always came out more or less identical so i just got the entire comic series and did em all in one run
both results includes DeflOpt optimizing
Full series 664 files 209 MB (219.175.993 bytes)
PNGwolf 198 MB (208.351.442 bytes)
PNGout best 198 MB (207.622.449 bytes)
since pngout did so well constantly, im redoing a test with true color pictures as well as a palette pictures but with dithering