No.27788
However what?
No.27792
Based, I am unironically interested in this subject.
No.27796
>>27795this does not count as "grayscale" since grayscale images use all 0-saturated shades of gray between between white and black. These images only use 2 arbitrary colors. No in between shades whatsoever. The dithering uses different ratios of "spackling" of the two colors to create the illusion of a gradient when zoomed out.
Floyd-Steinberg dithering was used the most in the 90s, but was invented all the way back in 1976. That's 46 years ago!
No.27798
>>27792Thanks! If this reaches even one person, it's worth it. :)
No.27799
>>27789You can see the difference in this one in the thumb even.
No.27801
>>27800Also one downside I just noticed is I have leftypol zoomed out 10% by default and it makes these look all fucked up lol
No.27802
>>27789The indexed looks like it was taken in dense smoke. Get your eyes checked.
No.27803
>>27800thanks for sharing!
>>27802my vision is good. i got my eyes checked when I got my license renewed. I appreciate your opinion.
No.27804
>>27800Jarvis, Stucki, Sierra, and Atkinson algos all strike me as having particularly strong edges compared to Floyd-Steinberg
No.27805
>>27802>The indexed looks like it was taken in dense smokethe image looks good not on its own merits, but it looks good considering it has 532,939 fewer colors than the original. Going from 532,693 to only 24 colors and maintaining that level of detail is impressive! Feel free to disagree. I get what you mean about the smokey look. A sevenfold drop in size is also pretty impressive. For a lot of images posted on the internet (especially non photographs) it could be useful. You know how many anime pictures only really use 4 or 5 hues, but without compression it comes out to thousands of colors?
No.27808
>>27789so what's the lesson here
No.27826
>>27808size and number of colors go way down with very little essential detail being lost
No.27827
>>27806that's really based
No.27829
>>27808OP needs to go to the optometrist
No.27831
>>27830These both look better than OP's compressed pictures and have smaller file size. OP BTFO
No.27851
>>27787>>27789bro the smaller size images look like shit in both of these examples. data is cheap nowadays, why the hell do we need to cut the size so much, fidelity is more important
No.27852
>>27831see
>>27791>>27851>why the hell do we need to cut the size so muchso we don't have to wait an hour for your image to load
No.27857
>>27831bro is trying to emulate lossy compression with a lossless format
No.27860
Popular image formats usually have very good compression. Compare this to scanned documents, where PDF has proliferated, despite DJVU having objectively better compression and faster rendering by a wide margin.
Look at this random book from archive.org (
https://archive.org/details/inferno00dant_2/). The DJVU looks much clearer than the native PDF with more than double the size and the PDF containing JPEGs has marginally more detailed illustrations at four times the size. The text of the DJVU looks crisper than that of both PDFs.
Most books on archive.org don't have DJVUs anymore, so I usually losslessly convert a directory of JPEG2K files to a PDF and transcode it to DJVU with this script:
#!/bin/sh
t=`mktemp`; d=`mktemp -d`
for i in $1/*.[Jj][Pp]2; do
jpeg2ktopam $1|pamtotiff >$t &&
tiff2pdf -o "$d/`basename $i|cut -d. -f 1`.pdf" $t
done
pdfunite $d/* $t &&
djvu2pdf $t > $2
rm $t; rm -r $d
This requires netpbm and pdf2djvu.
No.27861
>>27859I just did it because I thought it looked cool lol, I had already made it before the thread. I like how jpeg improves in some spots until it suddenly goes downhill massively, although that's mostly because the image has a weird quality already. jpeg wins in compression but it doesn't give any aesthetics like dithering or color reduction.
Although .avif is probably the best No.27865
>>27861>aestheticsI think what would help with aesthetics more than anything is an AI step when compressing. Reducing colors often leads to objects blending into each other or the background. Fixing this by hand takes a small eternity, so AI finding the borders of objects to find a setting with a given reduction of colors with little blending would be good.
And AI should also do a bit of phony coloring (not taking the nearest color from the reduced set) if that helps a lot against blending.
Oh and also, the AI should distinguish between things like machines and buildings on the one hand and organic structures on the other and apply something like the Bayer dither to the former and a less orderly dither to the latter.
No.28200
>>27787That's because dithering looks like shit and we have better displays now than we did in the 90s when color quantization was still a passable compression solution. But now we have jpeg.
Use jpeg instead and an encoder like mozjpeg for your Lenin portraits
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