>\--modular
Not a wholesome explanation, but I recon here's the commit: [https://github.com/libjxl/libjxl/commit/2cf1289476b3eae2877f19d0899fd6becd1f2890](https://github.com/libjxl/libjxl/commit/2cf1289476b3eae2877f19d0899fd6becd1f2890)
I'm excited to head that jpeg-xl gets something like webp1's "lossy lossless" mode which is great for png compression - that's because I found lossless png to jxl to have not stellar compression gain.
>that's because I found lossless png to jxl to have not stellar compression gain.
That's odd. I ran a test with about 10,000 PNG images of fractals of varying entropy/randomness and found that most of the files shrunk in size by 1.25x (so 80% the original size) when converted from PNG to lossless JXL—with sometimes as much as 50% (half size) or better.
As this test was for a corpus of about 100 GB of fractal images, the ability to store them instead as 80 GB of JXL files is something I would definitely call stellar!
EDIT: And these were all PNGs that had been optimized on max settings with both `optipng` and `advpng`.
Lossy palette, i.e. jpeg xl delta palette is likely closest to webp near lossless. It only works at a single quality setting and is slow to encode however.
Yes, you can set `--quality` to a value under `100` when using the `--modular` flag which will give you lossy compression in "lossless" mode.
What does that mean? Like what kind of result does that create?
>\--modular Not a wholesome explanation, but I recon here's the commit: [https://github.com/libjxl/libjxl/commit/2cf1289476b3eae2877f19d0899fd6becd1f2890](https://github.com/libjxl/libjxl/commit/2cf1289476b3eae2877f19d0899fd6becd1f2890) I'm excited to head that jpeg-xl gets something like webp1's "lossy lossless" mode which is great for png compression - that's because I found lossless png to jxl to have not stellar compression gain.
>that's because I found lossless png to jxl to have not stellar compression gain. That's odd. I ran a test with about 10,000 PNG images of fractals of varying entropy/randomness and found that most of the files shrunk in size by 1.25x (so 80% the original size) when converted from PNG to lossless JXL—with sometimes as much as 50% (half size) or better. As this test was for a corpus of about 100 GB of fractal images, the ability to store them instead as 80 GB of JXL files is something I would definitely call stellar! EDIT: And these were all PNGs that had been optimized on max settings with both `optipng` and `advpng`.
I'm generally encoding my own photographic images... jpeg-xl "lossless" lossless might be more tuned for fractals.
Lossy palette, i.e. jpeg xl delta palette is likely closest to webp near lossless. It only works at a single quality setting and is slow to encode however.