Using signed integer data in JPEG XL

[richard-viney]

Hi,

I'm curious about JPEG XL and signed integer data. I read that e.g. i16 data can be handled in JPEG XL, is this the case and if so is it exposed by jxl-oxide? Or do folks who need this usually just add a offset of 32768 and store it as unsigned data?

Thanks!

[tirr-c]

Internally all Modular (lossless) images are stored in signed integer, but currently jxl-oxide clamps sample values to 0..65536 when they're returned as u16 from ImageStream. So as for now you'll need to add 32768 if you're using jxl-oxide for decoding. (However adding support for i16 samples is not that difficult.)