[Hp5400backend-devel] Re: [sane-devel] New release of the alpha version of hp5400 SANE backend

[Thomas S. <sou...@ne...>]

> >Martijn have done more great work those days. It is still an alpha ver=
sion
> > 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 th=
e=20
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 backtrack=
ing
> (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 str=
ip,=20
most pixels are "absent". I'll send you on a separate mail a tiny part of=
 the=20
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=20
the flags are correct.


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

Thomas.