[sane-devel] Genesys, Canon LiDE 35/40/50/60

Pierre Willenbrock pierre at pirsoft.dnsalias.org
Thu Apr 27 06:53:56 UTC 2006

Gerald Murray schrieb:
> Quoting Pierre Willenbrock <pierre at pirsoft.dnsalias.org>:
>> Hi Gerald,
>> Gerald Murray schrieb:
>>> Tested:
>>> LiDE 35: 150,300,600,1200 using usb-1.1.
> --snip--
>> That is probably a calibration problem. There is no easy way to fix
>> that. What helped Henning was to clean the calibration area. The backend
>> is currently not able to cope with (much) dirt there. You can get a
>> distorted raw scan of the calibration area by enabling debugging. That
>> should give you a file named "black_white_shading.pnm". When scanned at
>> the higher resolutions(>=600dpi), it should have vertically striped
>> area(s), but only very few dirt particles.
> I have not figured out how to clean the calibration area.  There was no
> instructions that came with the scanner.  Is there some guide to how
> to take the parts apart?   There is one possible plastic hook pair on the 
> bottom, but it looks like a manuafacturer-only access point, requiring a 
> special tool.

Then i guess you need to live with the vertical stripes. But please send
the black_white_shading.pnm from a 1200dpi scan so i can try to find a
better calibration algorithm.

>>> Also a few slices across the image, possibly from a
>>> jerk of the head at that point in the scan.  On the whole, an acceptable
>>> image.
>> Did this happen because the scanner moved the head back to restart at
>> the buffer overflow position? If that is the case, i need to do some
>> more tuning on the acceleration tables. That should definitely not
>> happen(Though it is no reason not to put the code into sane-backends).
> It happened at 10 cm of an 11cm postcard scan.  The scanner does quite
> a bit of shuffling, and I thought it might be related to that forward/reverse
> timing in the shuffle.

I guess that did not happen all the time at the same position?

>>> HP2400: no change, not working.
>> Not working as in "refuses to move head/deliver useful data" or as in
>> "provides a 2400x1200dpi image"? For the latter case i do have a patch,
>> enabling a nearest match interpolation.
> The head never moves.  It goes into a calibration at the beginning, and
> never completes the calibration correctly, and then times out with a
> question on the lamp:
> [genesys] genesys_warmup_lamp: warmup timed out after 46 seconds. Lamp
> defective?
> scanimage: sane_start: Error during device I/O

Sorry, misread "HP2400" to be "2400 dpi"..


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