Highlights of the patch:
- Supersede MR !249
- Added FP16 and FP32 images support thus preserving HDR values (read / write, required libjxl 0.9+).
- Added Gray8 and Gray16 support (read / write).
- Indexed images are saved as Gray8 when palette is gray scale.
- Binary images are saved as Gray8 (does JXL natively support binary images?).
- Simplified writing process by partially removing the use of additional buffers.
- Added XMP metadata support by decoding/encoding Boxes.
- Changed maximum image size in pixels in accordance with JXL feature level 5 (still limited to 256 megapixels).
Compatibility:
- Older versions of this plugin load FP images correctly as UINT16 (obviously losing HDR info).
- HDR images saved with this patch are also loaded correctly by Gimp and Photoshop.
- Grayscale images saved with this patch are also loaded correctly by Gimp and Photoshop.
Compilation modifiers for cmake file:
- `JXL_HDR_PRESERVATION_DISABLED`: disable the FP support (behaves like previous versions).
- `JXL_DECODE_BOXES_DISABLED`: disable metadata reading (behaves like previous versions).
Let Qt rotate the image when the ImageAutotransform option is set to true.
In tests it also solves the image size control with the value returned by the options with certain rotations.
