[sane-devel] Backend for plustek Opticbook 3600

[stef]

Le samedi 20 février 2010 16:14:02, vous avez écrit :
> > 	Hello,
> >
> > 	regarding the gamma values you can extract the gamma tables sent to your
> > scanner by the windows driver from USB logs. Put them in a spreadsheet,
> > then you can insert the formula used by the genesys backend and compare
> > the reference and generated curves.
> 
> I am not sure at all how to get the gamma values from the snoop. After
> looking at some parsed logs there are no references to gamma values, but
> looking in the awk files (specifically the bulk_write_register) there
> should be some parsed output for them. Maybe I am using the wrong
> version of your awk files for this?
> 
> > 	For gain and offset, until calibration work I have nothing else to
> > advise you than trial and error. But by choosing a black/white target,
> > you may refine your tests. Scanned black areas should give values
> > slightly above zero. If no raise the offset. Once tweaked, you can adjust
> > gain until white areas give values of about 240 (0xF0).
> 
> Ok ill try this once I have the correct gamma settings.
> 
> > 	For the release date I can't tell. Next release should be close. When
> > your work should be terminated for your University course ?
> >
> > Regards,
> > 	Stef
> 
> I have about 3 weeks to finish the implementation really, after that the
> sooner the better for the release :).
> 
> Chris
> 
	Hello,

	the gamma table writes aren't well decoded by my scripts. But you can look 
for the following pattern just before the final data flow which corresponds to 
the scan:

genesys_write_register(0x5c,0x00)
genesys_write_register(0x5b,0x02)
URB  3467  control  0x40 0x0c 0x83 0x00 len     1 wrote 0x28 
sanei_genesys_bulk_write(512)=0x00 ... 0xff 
genesys_write_register(0x5c,0x00)
genesys_write_register(0x5b,0x01)
URB  3472  control  0x40 0x0c 0x83 0x00 len     1 wrote 0x28 
sanei_genesys_bulk_write(512)=0x00 0x00 ... 0xff
genesys_write_register(0x5c,0x00)
genesys_write_register(0x5b,0x00)
URB  3477  control  0x40 0x0c 0x83 0x00 len     1 wrote 0x28 
sanei_genesys_bulk_write(512)=0x00 ... 0xff

	3 weeks seems doable... 

Regards,
	Stef