[sane-devel] Epson Perfetion 2480 scanner

[Henning Meier-Geinitz]

Hi,

On Sat, Sep 04, 2004 at 06:36:59PM +0200, Oliver Schwartz wrote:
> > Negative scanning works fine, only in 2400dpi resolution I see the
> > interlacing effects (see the picture I attached to my first mail,
> > it was scanned with in transparency Mode).
> 
> This seems to be a peculiarity of Epson scanners. The same is reported 
> for the 1670, but I haven't seen it on my Acer scanner.

I have seen a similar effect with the Mustek BearPaw 2400 TA Plus. In
that case the reason is the type of CCD sensor. It's maximum
resolution is 1200 dpi, but it doesn't have 1 1200 dpi line per color
but 2 slightly offset lines of 600 dpi each. So upto 600 dpi only one
CCD line is used and the image data looks as usual. With 1200 dpi the
two lines are used. The image format is similar to an image with 6
different color components instead of 3. So linedistance correction
must be used to match the two lines and the lines must be
"deinterlaced".

Not sure if this is the same case...

Bye,
  Henning