I have just pushed v59 of the canon_dr backend up to our git repo.
This is an updated version of the patch I shared previously. The
calibration values are currently hard-coded for the C225, so the
quality is poor. But, we can at least get duplex color scans now. I
expect grayscale scans will
Marek, I'm sorry it has taken me a month to reply, life is a little
'different' these days :)
So I have gone back through every email thread I have had about the
DR-C225, and do have a set of logs from the windows driver. I will
attempt to determine which bit of magic we are missing. It will take
