All JXL images are actually PNG

Question

All JXL images are actually PNG

vanontom opened this issue 4 months ago · comments

Issue:
JXL images "show", but are actually PNG. Can't view or download the original JXL.

Reproduce:
Test pages (like jpegxl.info) seem to show properly, but files are not actually JXL
"Open image in new tab" on supposed JXL image results in file.png
"Save image as" on supposed JXL image results in file.png
Brain results in confused.jxl

Notes:
Browser: Firefox (124.0.1) (using JPEG XL Viewer addon via addons.mozilla.org)
OS: Windows 11 (23H2, build 22631)
Can't find much documentation. Do I have some Firefox setting wrong?

zamfofex · Answer 1 · Tue Mar 26 2024 05:58:23 GMT+0800 (China Standard Time)

You cannot get JPEG XL images to display on browsers without inbuilt JPEG XL support, so this extension has to convert them to PNGs so that the browser can display them.

Tom Vanon · Answer 2 · Tue Mar 26 2024 06:25:18 GMT+0800 (China Standard Time)

Thanks for the clarification. So this allows "viewing of JXL" by converting losslessly to PNG? Sorry, I could not find mention of "png" or conversion in docs (or Issues, Firefox Add-ons reviews) so I thought something was wrong.

zamfofex · Answer 3 · Tue Mar 26 2024 07:03:20 GMT+0800 (China Standard Time)

Yes, that is exactly how it works! Though it might not be “lossless” for HDR images, though I feel like that is tolerable.