[sane-devel] Backend for plustek Opticbook 3600

Chris Berry s0457957 at sms.ed.ac.uk
Sun Mar 21 19:01:39 UTC 2010


stef wrote:
> 	Hello,
>
> 	for the image quality, I think you could concentrate on on full sensor 
> resolution and 'half ccd' resolution. 
I'm not sure what you mean but I guess full resolution is the maximum 
hardware resolution of the scanner? If so then what is 'half ccd' 
resolution?

> In these modes AVEENB is of no influence 
> since no averaging or deletion occurs. Then you can adjust the offset to be 
> used for shading data. To find the correct offset some trial and error is 
> needed. You'll have to change it's value until bright vertical lines match the 
> closest dark vertical line in scans (you could scan only the white cover of 
> the scanner, lines are more visible). You may try first the offset values from 
> other GL841 scanners. 
>   
So I just do scans at full resolution of the white background and alter 
the shading offset until it evens out? Should be no problem....
> 	Once done, you may choose to keep averaging, but in this case you'll have to 
> tune compute_coefficients to do the same averaging than the planar method used 
> for the CCD_CANONLIDE35.
>
>   
Is this method you are talking about the large function added under 
canonlide35 in the send_shading_coefficients? If so I will try if i get 
time but as my hand in date is coming up I may not get time...

> Regards,
> 	Stef
>
>   
I should have the patch sent out to you by the end of the day, i'll 
include pierre, you and the people who also have the scanner for a bit 
of testing.

Also does this mean I can add my name to the developer list at the top 
of the genesys files :)  ?

Thanks

Chris



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