genesys: Canon Canoscan LiDE 35 - initialization issues (scanner head movement)
The driver seems to have issues initializing the scan process properly. It looks like it sends wrong commands confusing the device (like it tries to move the head backwards instead of forward. The stepper motor makes an unhealthy/noisy sound then). It only happens right on the start of the scanning process. If the device once started properly the scan process goes along correctly up to the end.
It never occurs when using 600dpi:
scanimage --format=png --resolution 600 > scan.png
It occurs for some seconds (noisy motor sound) if you try to shift the scanner head (-t 300). It begins to scan from "-t 0" nevertheless:
scanimage --format=png --resolution 600 -t 300 > scan.png
It nearly always occurs when using 200/300dpi:
scanimage --format=png --resolution 200 > scan.png
scanimage --format=png --resolution 300 > scan.png
If the scan started properly it also contains the gap between parking position and "-t 0" (additional white area at the top of the page). Like you would scan with "-t -10".
The bug seems to behave differently when enforcing calibration. It might work properly then.
Sometimes it is possible to scan at 200/300dpi and with proper shifting (-t) but it usually falls back reliably to bugged state on next scan.
System:
SANE 1.0.28
Arch Linux 5.4.11 x86_64 GNU/Linux
Canon Canoscan LiDE 35
Genesys backend