Social Media Channel
boosted
RE: https://mastodon.social/@aslakr/115854460446343714
(Changed the file < 8.3 megapixels and stopping Mastodon-rescaling)
It's a pity that #Mastodon increases the file size nearly 2.6 times by converting from palleted to 24 bit PNG.
% pngcheck -q -p e08463_353cfb9f6bf646159fdf9dc573b1080e.png bff448d488087b22.png
File: e08463_353cfb9f6bf646159fdf9dc573b1080e.png (100671 bytes)
0: (255,255,255) = (0xff,0xff,0xff)
1: (233,240,221) = (0xe9,0xf0,0xdd)
2: ( 0, 0, 0) = (0x00,0x00,0x00)
File: bff448d488087b22.png (264684 bytes)
Lossless converting the palleted PNG (at 100671 bytes ≈ 101 kB) to JPEG XL result in a file at 25178 bytes ≈ 25 kB.
Converting lossless to webp, using
cwebp -lossless -m 6 -z 9 -o e08463_353cfb9f6bf646159fdf9dc573b1080e.{webp,png}
the file is 85118 bytes ≈ 85 kB. Lossy webp (i.e. without `-lossless`) is 437632 bytes ≈ 438 kB