[sane-devel] Canon LiDE 90

[Pierre Willenbrock]

Hi,

Guillaume Gastebois schrieb:
> Hello,
> 
> So, what's the next step ? Re-enabling shading ?

Yes, but only after the shading-calibration is able to get black level
information.(This really needs a better api..)

> Do you think that last modification "for (i = 150; i..." is necessary ?

Yes. Some time back, that part of the code just used the middle half of
the scan, exactly to drop the dummy black pixels at the begin. That
didn't work too well, missing some low black levels.

> Is it time to fine tune registers 52... ?

Try increasing register 53, 55, 57 by one. Attached is a small program,
that shows the probability of any two-byte pair appearing in a file. It
takes the file as input and dumps an portable anymap(pnm) as output.
I created that program for something completely unrelated, but it proved
useful.

I used it on offset1_1.pnm(as offset1_0.pnm is only black).
The image should show a fuzzy vertical and horizontal bar, near
top/left. Currently, the horizontal bar is more a line, the vertical bar
is correct(it shows the relationship between the low byte of one pixel
and the high byte of the _next_ pixel).

> Regards
> Guillaume

Regards,
  Pierre

> Pierre Willenbrock a écrit :
>> Guillaume Gastebois schrieb:
>>> Hello,
>>>
>>> Yep, I write "for (j = 150; j...." instead of "for (i = 150; i....."
>>> Now second set seems good. Result is on : 
>>> http://ggastebois.free.fr/lide90_snoop/20_test1.tar
>>>
>> Hi,
>>
>> i am sorry, i actually wanted 450, but didn't realize until just now. I
>> missed that the calibration dump images are really grayscale images,
>> although stored in color pnms. 1 pixel in image is 3 pixels for the
>> calibration...
>>
>> I hope this fixes that part of the calibration.
>>
>> Regards,
>>   Pierre
>>
>>> Regards
>>> Guillaume
>>>

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