I have a Canon LiDE 120 scanner connected to a Ubuntu 16.4 box. The scanner is detected, but the produced images are completely black.
More precisely, if I press "scan" or "preview" in xsane
, there is a short initial noise from the scanner motor, then nothing is happening for about half a minute, then the scan is performed (lamp on) and the resulting image is black. Scanning from the command line with scanimage
, the behavior is exactly the same (including delay). The scanner does work on Windows, so the hardware should be fine. Using the Color picker tool in Gimp a few times, I checked that the color is totally black (all color values equal 0).
Maybe the delay for half a minute is somehow connected to the problem? (Could be some sort of a timeout)
The picture from searching for this problem is not completely clear: First, Sane support for the Canon LiDE 120 was problematic at least till 14.04. Apparently a few setups on 16.04 are running flawlessly, others seem to have the same problem. As a source of errors it was reported that the lock switch at the lower surface of the scanner has to be unlocked (this is the case, I also tried lock-unlock-restart) and USB ports behind an external USB hub (scanner is directly connected, I tried different USB ports).
From lsusb:
Bus 001 Device 004: ID 04a9:190e Canon, Inc.
Scanimage:
scanimage -L
device `genesys:libusb:001:004' is a Canon LiDE 120 flatbed scanner