This is a simple dng converter tailored for the Panasonic DMC-GX85 (the camera
the author owns) aimed towards efficiently re-compressing .RW2 files with
JPEG-XL. It uses libraw, tifffile, and exiftool to create DNG 1.7.1.0 output
preserving the Bayer data from a [B G G R] camera. Lossless JPEG-XL compression
is used, with a path towards enabling lossy compression.
JPEG-XL has the potential to turn a 19M RW2 into 12M of image data without loss, or a several-megabytes file in lossy mode, while retaining the bit depth of the sensor.
This project is in very early stages. It shouldn't be trusted with irreplaceable photographic data.