[sane-devel] New release of the alpha version of hp5400 SANE backend

[Thomas Soumarmon]

> >Martijn have done more great work those days. It is still an alpha version
> > as it is not full featured and there are still two major bugs :
> >* the image goes fuzzier as the resolution increases
> >* 1200 and 2400 dpi images are scrambled.
> >Except of that, 75 and 150 dpi are working pretty well.
>
> What do you mean by fuzzier?
> Is this the problem of vertical shift between separate color components
> (R G B)?

Yes. That point is "under control" as we know how to correct it during the 
image composition, reading colors on separate lines.


>
> Problems with scrambled images could be caused by an overflow of the
> internal data buffer (at least that's what I found with niash12/14/19
> chips). In that case, you should be able to correlate this to backtracking
> (quickly moving back and forth of the lamp).
> Do the scrambled images also occur if you scan only a narrow vertical
> strip?

At first I thought you would be right but even with a narrow vertival strip, 
most pixels are "absent". I'll send you on a separate mail a tiny part of the 
vertical strip. It shows colored vertical lines (red and green).
It might be related to the query sent to the scanner. We have to check if all 
the flags are correct.


Thank you again for sharing your experience and for your help.

Thomas.