[sane-devel] Canon LiDE 90

[Pierre Willenbrock]

Pierre Willenbrock schrieb:
> Guillaume Gastebois schrieb:
>> Hello,
>>
>> You can find all of that on : 
>> http://ggastebois.free.fr/lide90_snoop/no_shading.tar
>>
>> What seems strange in calibration ?
>>
> 
> The minimum/maximum values retrieved from the scans do not scale with
> the offset values, but in a rather random manner. The calibration
> expects a linear relationship.
> 
> Regards,
>   Pierre
> 

Hi,

the raw offset calibration data looks horrible. Too bright and noisy.
Please change the too bright/too dark thresholds for
gl841_offset_calibration in genesys_gl841.c like this:

@@ -4545,9 +4546,9 @@
                  val =
                      first_line[i * 2 * channels + 2 * j + 1] * 256 +
                      first_line[i * 2 * channels + 2 * j];
-             if (val < 10)
+             if (val < 1000)
                  cmin[j]++;
-             if (val > 65525)
+             if (val > 40000)
                  cmax[j]++;
          }

Send/Put online the debug files offset*.pnm, and the
"gl841_offset_calibration: acceptable offsets: " lines from the debug
output(Or the whole set, whichever is more convenient ;-)).

Regards,
  Pierre