[sane-devel] Feedback Canon MG7750 / PIXMA backend

[FS]

Hi all,
I recently bought a Canon MG7750. And I was rather badly surprised by 
Canons own scanner driver for Linux.
Hence, first and foremost a big thank you to the SANE developers for 
adding support for this model.

Since you asked for testers I made some scans with different settings.
All resolutions up to 600DPI work fine (http://susepaste.org/350ec6bf ).
1200DPI and 2400DPI work but the result looks rather strange (=unusable) 
(http://susepaste.org/a7dbf6b8 and http://susepaste.org/1ac92632 ).

All three files should show exactly the same picture.
For scanning only the resolution changed. No other setting was changed.
To reduce file size I compressed the images pretty strongly before 
uploading. The 2400DPI scan is also reduced in resolution.
Hence, quality is well below the real scan quality.
But the problem is clearly visible.

SANE backends are from sane-backends-git20160322. OS is openSUSE Leap42.1.

I hope this information helps. I will be happy to test newer versions or 
tell you more information.

Cheers
Frank