[sane-devel] pixma MP810 working with sane

[Nicolas]

Then sounds good news!

I'll commit that into CVS promptly

Could you send sample images scans, 1 at 2400 dpi and 1 at 4800 dpi, to
see what is the issue at these resolutions, and if a solution can be
brought simply ?

So looks like MP8x0 and MP9x0 series probably share the same CCD sensor
(as plane shifting is the same), but the the shift is opposite between
those 2 series, maybe because the sensor is placed opposite on MP8x0
series due to the ADF. 

Does MP810 sensor scans the page from left to right ?

Nicolas


Le samedi 30 août 2008 à 19:20 +0200, Arne a écrit :
> Hi Nicolas,
> 
> thanks for your help.
> I have tried tried the value change to 50 as you suggest and I have noticed 
> the following changes (normal glass scan, I have never tried using the 
> film scan unit):
> 
> 75dpi:
> before: OK   now: color plane shift
> 
> 150+300+600+1200dpi:
> before: color plane shift  now: OK!
> 
> 2400+4800dpi:
> before: color plane shift  now: vertical fringed and aspect ratio not 
> correct
> 
> This is already much better as the most important resolutions (150-1200dpi) 
> are working fine now.
> At the moment I don't have time for further testing, I will send you later 
> tonight or tomorrow more details and some sample scans so maybe we can fix 
> the remaining problems (75dpi and 2400+4800dpi) too.
> 
> Best regards,
> Arne
> 
> 
> On Sat, 30 Aug 2008, Nicolas wrote:
> 
> > Hi, 
> > 
> > I've added a while back some code to the pixma backend to deal with CCD
> > color planes shifts, and it currently works fine with MP970.
> > 
> > For MP800, 810, it was based on some info I've got on bug reports (for
> > instance bug #310463), but this code has not yet been tuned, especially
> > the amount  of shifting to apply. 
> > This should not be a big deal to fix now.
> > 
> > Could you first confirm that you get the same result with ADF and with
> > glass scans ? 
> > 
> > Then, you could do some tries by changing the amount of shifting applied
> > by the backend:
> > 
> > In backend directory of the latest CVS version, in file pixma_mp150.c 
> > 
> > Could you change line 980 from:
> > 
> > mp->lines_shift =  s->param->ydpi / 100;
> > 
> > to
> > 
> > mp->lines_shift =  s->param->ydpi / 50;
> > 
> > Recompile, and see how the amount of lines shifting changed ?
> > 
> > Nicolas
> > 
> > Le jeudi 28 août 2008 à 17:41 -0700, tux99 a écrit :
> > > 
> > > 
> > > Jean-Nicolas Gautier wrote:
> > > > 
> > > > Hello,
> > > > I bought a pixma MP810 one year ago. It works but I have the problem 
> > > > with color alignment : yellow, magenta and cyan layers are shifted.
> > > > 
> > > 
> > > I have the exact same problem also with a Canon Pixma MP810.
> > > I'm using Mandriva 2008.1 but I have installed the latest CVS
> > > sane backend (sane-scm-2008-08-28).
> > > # scanimage -V
> > > scanimage (sane-backends) 1.1.0-cvs; backend version 1.1.0
> > > 
> > > I'm available for testing any bugfixes or for any further details, too.
> > > 
> > > Arne
> > > -- 
> > > View this message in context: http://www.nabble.com/pixma-MP810-working-with-sane-tp19031727p19211863.html
> > > Sent from the SANE - Dev mailing list archive at Nabble.com.
> > > 
> > > 
> > 
> >