[sane-devel] Canon 9000f MK2 48bit Color Gamma Too Dark

Roger rogerx.oss at gmail.com
Fri Apr 1 01:33:12 UTC 2016

I think I've found a bug (when using a Canon 9000f MK2), scanning at 16 bits 
color (AKA "Color") produces an apparent proper image gamma of 2.2, while 
choosing to scan at "48 bits color" produces an image too dark, or an image 
having an approximate gamma of less than or equal to one.

Both scanimage and xsane, as well as enabling and disabling Color Managment 
exhibit this problem.

A temporary work around when scanning at "48 bits color", would be to open the 
scanned image within Gimp, opening Levels and moving the middle slider on the 
first slider to a value of 2.2.  (Hence, first selecting Auto Level, then 
adjusting the gamma to 2.2.)

Feedback on this issue?


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