[sane-devel] Canon LiDE 90

[Guillaume Gastebois]

Hello,

I inverted colors with gimp. Sorry I forget this operation.


Selon postmaster <postmaster at tsleg.com>:

> Hi,
>
>
> How did you get this one :
> http://ggastebois.free.fr/lide90_snoop/toto_10_0_0_comment.jpg ??
>
> Colors are not inverted ...
>
>
> Guillaume Gastebois a écrit :
> > Hello,
> >
> > I modified registers 10-1d with :
> >
> > {0x04, 0xd3, 0x04, 0xd3, 0x02, 0xa3, 0x20, 0x06, 0x00, 0xff, 0x24, 0x00,
> > 0x00, 0x04},
> >
> > and now the led is really white (red green and blue by moving eyes).
> >
> > Led calibration seems to be good.
> >
> > But calibration is always 60s long.....
> > I need help.
> > Thanks
> >
> > Regards
> > Guillaume
> >
> > Pierre Willenbrock a écrit :
> >
> >> Hi Guillaume,
> >>
> >> Guillaume Gastebois schrieb:
> >>
> >>> Hello,
> >>>
> >>> Why calibration is so long (~50/60s) ?
> >>>
> >> It is probably failing. Should take about 3-5 seconds. Look at the logs,
> >> the calculated averages and calibration are dumped there.
> >>
> >>
> >>> What are /* Start of white strip in mm (y) */ and /* Start of black mark
> >>> in mm (x) */ in genesys_devices.c ?
> >>>
> >> Those are configuration values for calibration steps. I don't know if
> >> any of these are currently used or if the values are hardcoded.
> >>
> >> I think the start-of-black-mark is used to detect the beginning of the
> >> document area for some gl646 scanners. The start-of-white-strip was once
> >> used in shading calibration. Currently, the shading calibration is setup
> >> for a calibration area looking like this:
> >>
> >> home position
> >> +--------------------------------
> >> !   black area
> >> +--------------------------------
> >> !   white area
> >> +--------------------------------
> >>
> >> The border between black area and white area is autodetected per pixel,
> >> as the border is usually not straight.
> >>
> >> You scanner seems to offer only a white area, so we will need to do
> >> shading calibration differently. My current idea is this:
> >> * always gather data on a white area
> >> * for black data, reduce the led exposure time to the minimum(0x101,
> >> those registers cannot be set to 0. per byte.).
> >> * for white data, use the normal exposure times
> >> I tried something like this for offset calibration, to see if there is
> >> any difference between white area+0x101 exposure time and black
> >> area+normal exposure time. There was no difference in the final images,
> >> and i think the resulting calibration was the same as well.
> >>
> >>
> >>> Regarding the log file you said :
> >>> W  ! 0x23 ! 0x050 ! dac value rgb(offset value)
> >>> W  ! 0x2b ! 0x028 ! pga gain rgb
> >>> But on debug, I see that these two registers are never written.
> >>>
> >> 0x23 and 0x2b are merely convenience registers. Writing to 0x23 and 0x2b
> >> is equivalent to a write to each of 0x20-0x22 and 0x28-0x2a. For
> >> cis-sensors, there is only one channel used, so we could get away with
> >> only two registers writes(for the correct channel or 0x23/0x2b), but
> >> this won't work for ccd-sensors.
> >>
> >>
> >>> Another thing : when scaning in color the leds are blue ????
> >>>
> >> I'd expect a shade of white, perhaps blueish. my scanner does a
> >> magentaish white. You may also see the single colors when quickly moving
> >> your eyes relatively to the scanner.
> >>
> >> Regards,
> >>   Pierre
> >>
> >>
> >>
> >
> >
>
>