jpeg xl support

[SoniEx2]

we would like to see jpeg xl for user avatars as an alternative to the more conventional options of gif, regular jpeg, and png. jpeg xl tends to be significantly smaller too.

[ctrlaltca]

KVIrc uses Qt6 to load images. Qt6 actually supports there formats: https://doc.qt.io/qt-6/qimagereader.html#supportedImageFormats
I know unofficial Qt plugins for JPEG XL exists, even KDE used to ship one, but this is not something we can fix from inside KVIrc. Sorry

[SoniEx2]

you don't need to use QImageReader, you just need to pass the data to Qt in a format it understands.

[ctrlaltca]

Thank you for the explanation.