Support of JPEG2000 files with subsampled channels
Submitted by Jehan
Some JPEG2000 can have subsampled channels. I am not sure why the OpenJPEG decoder does not just take care of it itself (re-encoding the missing color information), but for
a6_mono_colr.j2c, available inside the openjpeg-data repository, it didn't.
It may be because that was a J2K, with no header, so the solution may be as simple as adding some decoder parameter, I don't know.
See the discussion I had with OpenJPEG developers, and in particular this message: https://github.com/uclouvain/openjpeg/issues/1103#issuecomment-371988889
Version: git master