[sane-devel] Canon LiDE 90

[Guillaume Gastebois]

Hello,

Selon Pierre Willenbrock <pierre at pirsoft.dnsalias.org>:

> 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..)

How to do that ? Do you mean a better api adapted to lide 90 or for all genesys
backend ? Do you have some code ?

>
> > 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).
>
OK, interesting program. I'll try it tonight.

One more thing, what are you thinking about output image quality ? Is that
normal with todays calibration or is it another problem ?

Regards
Guillaume

> > 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
> >>>
>
>