On 04-Sep-2000 Stephen Williams wrote:
>
> That Moire is caused by the interaction of the half-tone pattern in the
> document and the sampling of either the scanner or the scaler. The frequency
> of the pattern is the difference between the frequency of the halftone
> on the page and the sample frequency of the scaled video.
[cut]
Without any doubt, the more complete answer !
Congratulations !
I appreciate very much your help (Johan Bengtsson & Peter Kirchgessner too, and
others, but I don't remember the names, because I had too many answers :-)))
I have to admitt I didn't understand all the explaination (my english's not
rich enough !). But with a combination of all the suggestions, I removed the
spots :-) (high res scan + blur + scale)
I have another question (in fact 2) :
- "The best hope, though, is to find the natural resolution of the scanner,
and scan at that resolution." How can I find that ? Is there a precise way to
do that ? No resolution gave me entire satisfaction... and perhaps the one that
worked for this image won't work with another one...
- "Scan at maximum resolution, then scale down (_not_ resize..) the image in the
Gimp, and then sharpen it." What's the difference beetween "scale" and "resize"
? Is it a matter of "resolution" and "pixels" ? For this image, I used the
option that allowed me to change the width from 900+ px to 800 px. How do you
call that : resize, or scale ?
Thanks
-- Arnaud Calvo <arnaud@calvo-france.com> 49240 Avrillé-- Source code, list archive, and docs: http://www.mostang.com/sane/ To unsubscribe: echo unsubscribe sane-devel | mail majordomo@mostang.com
This archive was generated by hypermail 2b29 : Wed Sep 06 2000 - 14:42:02 PDT