Originally Posted by
NM64
That must be a limitation of the plugin, because AVIF definitely supports 4:4:4 chroma, and it even supports up to 12bit per channel making the smaller color range of YUV vs RGB a complete non-issue (though I'm unsure how the file size would react if using 10+ bit with lossless, I just know that using 10+ bit with lossy video formats historically reduced the the file size rather than increased it even if the source content was 8bit - see the many many 10bit anime encodes from 8bit blu-rays).
It is still YUV, not RGB.
Originally Posted by
NM64
Now obviously inflating 8bit RGB content to 10bit YUV isn't actually "lossless", but isn't the goal here to be visually lossless rather than mathematically lossless? This isn't for archival purposes after all - aren't we just trying to just not lose any visual fidelity?
Mainly, black levels are not preserved well.
Originally Posted by
NM64
It may be worth noting however that the mobile-sourced WebP images are in lossy WebP and therefore YUV, but I'm uncertain what colorspace and bitdepth our lossless WebP images use (such as for the OP thumbnails) - presumably 8bit RGBA? This does make me wonder if working with 10bit would be ideal then for the elusive waifu2x'd 800x600 chroma channel + mobile 1280x960 luma channel images.
Yes, it is 8-bit RGBA.
Originally Posted by
NM64
For reference, the "merged" images were saved as lossless WebP but with unknown colorspace and bitdepth. Here's an example file - perhaps you can tell me what colorspace and bitdepth it's encoded with?:
Code:
julian@julians-MacBook-Pro:~/Downloads$ identify hQl.webp
hQl.webp WEBP 1280x960 1280x960+0+0 8-bit sRGB 548326B 0.030u 0:00.036