Nov 5 2021
Any updates? ImageMagick agreed this is a bug.
Sep 27 2021
Just FYI: 14 days ago ImageMagick already fixed JXL integration since in 0.5 version JXL now requires setting color space info. JXL can preserve JPEGs losslessly! https://github.com/ImageMagick/ImageMagick/pull/4064
May 5 2021
off-topic for this ticket
Why you are not just using SVG directly??
May 4 2021
all the extra color information that current cameras capture.
JPEG XL supports mathematically lossless from JPEG convertion and back and also better than AVIF. Soon to be added in Chrome.
AVIF now activly supports HDR with PQ or HLG transfer.
automatically converts CMYK images to RGB
This file uses APP14 marker's ColorTranform set to 0, which means RGB for 3 components and CMYK for 4 components. That is a common problem. This file has ColorTranform 2 which is YCCK. See thumbnail, that is broken. https://en.wikipedia.org/wiki/File:Channel_digital_image_CMYK_color.jpg
This uses YCCK color space (K is from CMYK, YCC --> to CMY). Please fix the thumbnail.
gAMA of 0.45454544 is not sRGB, not at all, the sRGB tranfer function is piecewise. It destroyes the picture in mastercard article (see my comment there on talk page) and in SMPTE color bars (in both cases it should be the same 8 bit values, check with Chrome, Photoshop still does not support gAMA, sigh).