[sane-devel] Bypassing calibration in CanoScan LiDE 60

[Pierre Willenbrock]

Tom Brush schrieb:
> For a scanner-camera project featured in Make magazine, (
> http://makezine.com/14/scannercamera/ ) the author uses SANE to bypass the
> calibration step, because it would fail after his physical modifications to
> the sensor.  The model he uses is a Canon CanoScan LiDE 20.  His actual
> directions can be found at: http://www.make-digital.com/make/vol14/?folio=78
> The modifications in the Plustek driver config. file are as follow:
> 
> On line 105, change option skipCalibration 0 to option skipCalibration 1
> On line 111, change option skipFine 0 to option skipFine 1
> On line 116, change option skipFineWhite 0 to option skipFineWhite 1
> 
> The scanner I have is the CanoScan LiDE 60, which uses a different driver,
> the Genesys.  None of the equivalent config. options are available.  I am
> new to this, but is there a way to perform a similar command to skip the
> calibration steps for the CanoScan 60?
> 

Hi Tom,

you can bypass the whole calibration process but you need to change the
sourcecode for this, and recompile and install sane.
The changes needed are commenting out lines 3707 to 3714 in genesys.c
and changing lines 2888 and 2889 of genesys_gl841.c from
> ((flags & SCAN_FLAG_DISABLE_SHADING)?
>  OPTICAL_FLAG_DISABLE_SHADING:0) |
to
> OPTICAL_FLAG_DISABLE_SHADING |

I don't think calibration will get in your way, but it requires a
working lamp. There is a cheap way to switch the lamp off during scan:
change line 4118 of genesys_gl841.c from
> 0
to
> SCAN_FLAG_DISABLE_LAMP

It is possible to completely disable the lamp, for this, change lines
2892 and 2893 from
> ((flags & SCAN_FLAG_DISABLE_LAMP)?
> OPTICAL_FLAG_DISABLE_LAMP:0)
to
> OPTICAL_FLAG_DISABLE_LAMP

You may need to change values on lines 100, 101 in genesys_devices.c.
Those are the analog offset(line 100) and gain(line 101), in hexadecimal.

Regards,
  Pierre