[sane-devel] Canon LiDE 90

[Guillaume Gastebois]

Hello,

I updated from CVS and modified flag GENESYS_FLAG_DARK_WHITE_CALIBRATION 
in GENESYS_FLAG_DARK_CALIBRATION.

Summary of current modifications :
	genesys_devices.c : see attachment
	genesys_gl841.c : added SCAN_FLAG_DISABLE_LAMP (line 4461), commented 
"status = gl841_feed(dev, 280)" (line 4241 and 4843), modified 0 to 150 
in "for (i = 150; i < num_pixels; i++)" (line 4617 and 4733).

Tonight I play with 52-57 regs.

I test 01/03/00/00/00/00, 01/04/00/00/00/00, 01/05/00/00/00/00, 
02/03/00/00/00/00, 02/04/00/00/00/00, 02/05/00/00/00/00.

Result of experiment can be found on :
http://ggastebois.free.fr/lide90_snoop/21_tests.tar

Is that true that as written in genesys_devices.c : "/*[GB](HI|LOW) not 
needed for cis */" because bests results are found with regs 52-57 with 
01/03/05/07/09/11 !! Results of this test on : 
http://ggastebois.free.fr/lide90_snoop/21_test2.tar

Another thing : I always have a brither vertical line where there is a 
small black rectangle in the calibration area.

To finish, I find that images seems to be more in relief as reality. Do 
you understand what I say ? To speak clearly, when there is 0.1mm real 
relief between paper and glass, on the image we have an impression of 
1mm relief ! Why ????

Regards
Guillaume

P.S. : Where is located this new code for GENESYS_FLAG_DARK_CALIBRATION 
? I used meld to see differences between my genesys_gl841.c file and 
this from CVS and only see my modifications !!!

Pierre Willenbrock a écrit :
> Pierre Willenbrock schrieb:
>> 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..)
> 
> I commited a prerequisite for shading calibration to work for your
> scanner. When enabling shading, update from cvs and then use
> GENESYS_FLAG_DARK_CALIBRATION instead of
> GENESYS_FLAG_DARK_WHITE_CALIBRATION.
> 
> Regards,
>   Pierre
> 
>>> 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
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