add support for JXL frame optimizations

[johnkw]

Is your feature request related to a problem? Please describe.

magick supports multiple frames for jxl, which is great. But apparently it makes no attempt to encode them with subtraction or modify any of the other frame-related features.

Seemingly at the moment magick doesn't support any frame optimization? (Apologies, but if it does, they aren't easy to find documentation on.) Ideally it would be on by default, so that if you include the same file repeatedly, the output jxl doesn't get much bigger.

Describe the solution you'd like

New command line option to support (or disable?) frame optimization.

Describe alternatives you've considered

No response

Additional context

No response

[urban-warrior]

You can try using -layers optimize, or explore specific options like optimize-frame, optimize-plus, and optimize-transparency. These directives operate on the image sequence to reduce file size or improve rendering efficiency. Note that ImageMagick performs no additional optimization within the JXL coder itself—these are the only optimization methods currently supported in this context.

[johnkw]

Thanks, however those options just make things crash in different ways:

$ magick rose: rose: -layers optimize out.jxl
magick: FramesNotSameDimensions `out.jxl' @ error/jxl.c/WriteJXLImage/1179.
$ magick rose: rose: -layers optimize-transparency out.jxl
Aborted (core dumped)
$ magick -version
Version: ImageMagick 7.1.1-47 Q16-HDRI x86_64 22763 https://imagemagick.org
Copyright: (C) 1999 ImageMagick Studio LLC
License: https://imagemagick.org/script/license.php
Features: Cipher DPC HDRI Modules OpenMP(4.5)
Delegates (built-in): bzlib cairo djvu fftw fontconfig freetype gslib gvc heic jbig jng jp2 jpeg jxl lcms lqr ltdl lzma openexr pangocairo png ps raqm raw rsvg tiff webp wmf x xml zip zlib zstd
Compiler: gcc (14.2)

[urban-warrior]

Yikes! We see the issue and have a fix. We'll commit the patch within a day or two. Thanks.