[sane-devel] Canon LiDE 90
guillaume.gastebois at free.fr
Wed Jan 30 21:00:17 UTC 2008
>But you can ignore led-calibration for now, that is not essential when
>debugging the backend. Just make sure the exposure settings in
>Genesys_Sensor.regs_0x10_0x1d are good, for example from an usb log the
>last register write to 0x10-0x15 before receiving actual scanned data.
>If those stay all zero, the rgb-leds in your scanner are very probably
>not controlled using the rgb-led-control-feature of the gl84x.
>You can disable led calibration by commenting out the code in
>genesys_flatbed_calibration. Offset/Gain calibration can be commented
>out when the values in Genesys_Frontend are good, Shading calibration
>can be disabled when you add OPTICAL_FLAG_DISABLE_SHADING to the flags
>for gl841_init_optical_regs_scan. When shading calibration is disabled,
>you get vertical stripes, the others lead to too dark/bright r/g/b
>Things that may be missing:
>* leds need to be controlled correctly
>* cis-sensor needs to get the correct clock signals(line toggle+pixel
> clock, half-resolution signal is optional for now)
>* the analog frontend registers need to be setup correctly in
>* the readout position in the data stream from the analog frontend may
> need tweaking(registers 0x52,0x53)
>When that is done, you should be able to get an image from your
>scanner, although calibration may be lacking.
OK, i see some image (very far to end result...). But can you explain to
me how to know the correct values for genesys_frontend ????
These parameter have big influence on resulting image.
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