Re: detrammage

Douglas Gilbert (dgilbert@interlog.com)
Fri, 03 Dec 1999 08:38:12 -0500

Dave Hill wrote:
>
> Philippe Amelant wrote:
> >
> > hi, i 'am french and i don't speak english very well so
> > please be indulgent.
> >
> > i vould like to know howto make a "detrammage"
> > i don't know the english word to say that...
> > this operation is required when you scan from mag
> > else you obtain an ugly image...
> > i hope you understand what i mean ...
> >
> > thank
> >
>
> Hello Philippe,
>
> I think that you mean "descreen". This is to get rid of the
> nasty pattern that you get when scanning a magazine or
> newspaper image. It is caused by the dots that make up the
> image interfering with the scan.
>
> If you are using GIMP as your image processor, there is a
> descreen filter in "Filters -> Enhance -> Despeckle" that
> will go the job.
>
> If you don't have GIMP, you can try softening the image if
> your backend drivers supports it, or for a last resort, try
> this:-
>
> Carefully (!!) place a suitable sheet of glass on the scanner
> bed and put the image on top of that. Scan as usual. The glass
> will slightly defocus the image and remove the pattern. Be very
> careful not to scratch the scanner's own glass!!

So that is why I get that effect when I scan magazines!
That has been puzzling me for a long time.

Thanks for that useful insight.

Doug Gilbert

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