I have some photos with the .jxl filename extension. They are in the new image format known as JPEG-XL.
I have installed GNOME's new image viewer program named Loupe or Image Viewer in Ubuntu 24.10, like this:
sudo apt install loupe
(Loupe is an alternative to the older GNOME program known as Eye of GNOME)
When I open a JPEG-XL file, I get this error:
Could not Load Image
The image format "JPEG XL image (image/jxl)" is known but not installed.
How do I install support for JPEG XL in Loupe?
As you can see in the Ubuntu source code for glycin-loaders, Debian has disabled the support for JPEG XL and Ubuntu uses the same package.
The only solution I can offer is to use the Flatpak version of Loupe that is supported by me, the maintainer of Loupe, and comes with JPEG XL support.