1. Description
2. Installation
3. Test

Qt plug-in to allow Qt and KDE based applications to read/write JXL images.

Work in progress experimental implementation using libjxl

kimageformats 5.89 contains almost identical plug-in like this one already. If you have kimg_jxl.so installed, don’t install qt-jpegxl-image-plugin. If your distribution maintainer built kimageformats without JPEG XL support, you may install qt-jpegxl-image-plugin. It is not recommended to have libqjpegxl.so and kimg_jxl.so installed at the same time.

!Important! Clone must be --recursive to include third party packages

Code for download and compilation:

git clone --depth 1 https://github.com/libjxl/libjxl.git --recursive
cd libjxl
mkdir build
cd build
cmake -DCMAKE_BUILD_TYPE=Release -DCMAKE_INSTALL_PREFIX=/usr -DJPEGXL_ENABLE_PLUGINS=ON -DBUILD_TESTING=OFF -DJPEGXL_WARNINGS_AS_ERRORS=OFF -DJPEGXL_ENABLE_SJPEG=OFF ..
make

Code for installation (run as root):

make install

Check if the image-jxl.xml file was installed to /usr/share/mime/packages/ folder and run (as root):

update-mime-database /usr/share/mime/

Make sure that the Qt 5 base development packages (qtbase5-dev on Debian/Ubuntu) are installed. At least Qt 5.14 is required.

Download and build:

git clone --depth 1 https://github.com/novomesk/qt-jpegxl-image-plugin
cd qt-jpegxl-image-plugin
./build_libqjpegxl_dynamic.sh

Install (run as root):

make install

1. Open /usr/share/kservices5/imagethumbnail.desktop with editor of your choise
2. Find line that starts with MimeType= and add image/jxl; to it's end, so line looks like MimeType=image/cgm; ... ;image/rle;image/avif;image/jxl;, save file.
3. Run update-desktop-database

cd testfiles
gwenview jpegxl-logo.jxl

Expected result:

JPEG XL support has to be explicitly enabled in digiKam. Go to Settings -> Configure digikam -> Views -> Mime Types and add jxl to the to the Additional image file extensions field: