Pinga 0.62 does not compress PNG as strong as 0.42
Grelle said, on 09/01/2024
Version 0.62 show more "soft" result, even if quality factor = 0. Version 0.42 give me more "pixelized" result on quality factor = 4. And file size is smaller, and it is what I needed. Can somebody tell me, should it work like this? Or something get wrong? I take a screen of settings and result on both versions. https://drive.google.com/file/d/1W6y__kEzDcRGkYdtoXYy5nziuelxW_p_/view?usp=sharing
drd said, on 14/01/2024
pinga 0.42 was with old settings that force pingo do 256-colours (or smaller) png. pinga 0.62 lose that ability and do only very soft compression. I often use that reducion images to 256 colours too, so I ask our developer to bring that functionality back.
cédric (dev) said, on 14/01/2024
> do only very soft compression no. that would be done according to the image data
Grelle said, on 15/01/2024
As I see, even pingo don't compress to 256 on lowest quality settings... So, can you clear things - can I hope new version of Pinga will have force 256 compression back? Or it isn't planned?
Aleksandr said, on 19/01/2024
Dear Cedrik, here goes an image https://img.imgdd.com/f210f3.938d9095-4927-4ef8-a24c-6ddb1310573f.png 71786 bytes, 600×100, 8bit TrueColorAlpha, 10598 colors It is not converted by Pingo 1.17 to palette as expected: $ pingo -s4 in.png 48817 bytes, TrueColor sRGB, 17685 colors Now let's try with VIPS 8.15.1: $ vips pngsave in.png out.png --palette --effort=10 22737 bytes, Palette sRGB, 256 colors What do you think about that?
cédric (dev) said, on 19/01/2024
> pingo don't compress to 256 on lowest quality settings the quality does not trigger the transform — e.g.-q=100,-q=1or auto could transform to palette (try it) > It is not converted by Pingo 1.17 to palette as expected not 'as expected'. palette should fit, but resized image are more challenging for the current heuristics > What do you think about that it would be easy to force a transform, harder to pick it heuristically TL;DR: the current palettization is not as good for 'image quality' as the precedent one FYI, old pingo/GUI used to use a ready to go lib but was removed due to license i wrote a new one, which have cons & pros pros: speed, colors pick & sort, low mem, size optimized cons: it triggers on what it should fit, no visual perception effort (nor dithering) > can I hope new version of Pinga will have force 256 compression back? maybe later but it needs some work
Grelle said, on 31/01/2024
thank you for explanations!