[sane-devel] Missing greys

[Pierre Willenbrock]

Hi Henrik

Henrik Uggla schrieb:
> I've got a Canoscan Lide 50. I have discovered that when I scan at 150
> dpi or more the greys are missing in depth (in the black end). But when
> I scan at only 75 dpi the result looks much better since darker and
> lighter pixels are mixed to show the right grey nuance. Is it possible
> to have this behaviour at higher resolutions as well and in that way
> "creating" those missing greys?

I can't explain why there is a difference between calibration for 75dpi
compared to 150dpi(You didn't scan them at different bit depth, i
guess). But anyways, dark shades were incorrect since the beginning of
Canon LiDE 50 support.

I had some improvements to the calibration process sitting in my local
copy since about 3 months, so i just committed them. You can get them
from the cvs repository. Test results for the current method are welcome.

Regards,
  Pierre