C-API getters/setters are indeed limited (to the ones that really used in real applications), your contributions are welcome (please use GitHub pull request for that).
Besides that, tiff/ppm writer is very limited, esp. in tiff part (no compression, no striping/tiling, etc, etc). It is not intended for use in any real application, this is just a placeholder, to allow LibRaw samples to write some files.
Use make_mem_image() and your preferred TIFF writer (e.g. libtiff) in real apps.
C-API getters/setters are indeed limited (to the ones that really used in real applications), your contributions are welcome (please use GitHub pull request for that).
Besides that, tiff/ppm writer is very limited, esp. in tiff part (no compression, no striping/tiling, etc, etc). It is not intended for use in any real application, this is just a placeholder, to allow LibRaw samples to write some files.
Use make_mem_image() and your preferred TIFF writer (e.g. libtiff) in real apps.