Features
- JPEG XL support, read and write, using the internal
pillow-jxl-plugin module. - JXL is now optimized by default.
.jxlfiles that previous versions ignored
are re-encoded on a plainpicopt -rrun. Only lossless JXL is touched; lossy
(XYB encoded) JXL is left alone, as lossy WebP is. - Lossless images convert to JXL with
-c JXL, which now leads the preference
order for still images ahead of WEBP and PNG. - New
--convert-jpeg-to-jxlconverts JPEG to JXL losslessly and reversibly:
the JXL stores the original JPEG bitstream and can restore it byte for byte.
Files carrying that reconstruction data are never re-encoded, so the original
JPEG stays recoverable. - New
--convert-webp-to-jxlconverts lossless WebP to JXL. Off by default
because JXL support is still much thinner than WebP's. - Both flags require
-c JXLas well. JPEG and WEBP are formats picopt already
processes by default, so unlike BMP or TIFF they cannot be gated by naming
them with-x. A plain-c JXLstill converts only GIF and PNG