XnView Software

Are there plans (or is it there already silently?) to implement a lossless crop for JXL? presumably reencoding any sliced areas losslessly (or near enough).

I guess it's a better idea to ask the developers of JPEG XL.

Here: https://github.com/libjxl/libjxl

meteorquake wrote: Wed Nov 12, 2025 7:05 pm Are there plans (or is it there already silently?) to implement a lossless crop for JXL? presumably reencoding any sliced areas losslessly (or near enough).

Most likely not

Many thanks. I suppose the question could be taken more broadly as to whether anyone in the IT world is looking at such a thing, such that xnview could use it (passing the file and selection rectangle values) without having to do the fine coding.

Lossless cropping of JPEG XL files is not as trivial compared to JPEG, because JPEG is a much simpler format compared to JPEG XL.
JPEG always use pixel blocks of identical size, JPEG XL however does not by dafault. JPEG Xl use blocks of different sizes to optimize the compression result... only whole blocks of pixels can be cropped from the image.
The only option I see to make a JPEG XL image editable in that way is to restrict the encoder to utilze uniform blocks only. But that option is not implemented in the encoder of JPEG XL atm, and that would be a request adressed to the developers of JPEG XL, not the developer of XnView.