On Mon Mar 24 15:34:46 2025 +0000, Connor McAdams wrote:
Yeah doesn't seem at all related to native using higher chroma subsampling like I suspected :/ I encoded a 4:4:4 image with libjpeg to confirm `identify -verbose` could actually identify a 4:4:4 JPEG, which resulted in:
jpeg:colorspace: 2 jpeg:sampling-factor: 1x1,1x1,1x1I then checked a JPEG produced by native which has:
jpeg:colorspace: 2 jpeg:sampling-factor: 2x2,1x1,1x1And similarly, by default we produce:
jpeg:colorspace: 2 jpeg:sampling-factor: 2x2,1x1,1x1It does give the `quality` value of native, which is 95 compared to what we have at 76. As I noticed before, upping the quality value does get us closer, but still further than I'd expect with a max_diff of 14. Really not sure why libjpeg is encoding images that are worse, must come down to some internal encoder conversion differences...
Alright, at least with that we get a significant improvement. Does the file size also roughly fall in the same range as native?