Descreen with slide scanning

  • Thread starter Thread starter Chris
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Chris

Hi
I've been given a load of slides to scan for inclusion in powerpoint
presentations. Unfortunately a lot of them are of photos in books
which are therefore halftone images.
In the scanner software - scangear CS for the Canon 8000f in photoshop
on a Mac in Photoshop CS - the descreen checkbox is greyed out when
using the ColorPosi film setting.
Any ideas?
Thanks
 
Chris said:
Hi
I've been given a load of slides to scan for inclusion in powerpoint
presentations. Unfortunately a lot of them are of photos in books
which are therefore halftone images.
In the scanner software - scangear CS for the Canon 8000f in photoshop
on a Mac in Photoshop CS - the descreen checkbox is greyed out when
using the ColorPosi film setting.
Any ideas?
Thanks
Click to expand...

Do a manual de-screen.
http://www.scantips.com/basics6c.html

Where Wayne is talking about 300 DPI and 600 DPI, he is scanning from a
letter size document,

For your slide, I would scan at the maximum optical resolution of your
scanner, 2400 dpi and up.

Then resize and use the blur filters.
 
Hi
I've been given a load of slides to scan for inclusion in powerpoint
presentations. Unfortunately a lot of them are of photos in books
which are therefore halftone images.
In the scanner software - scangear CS for the Canon 8000f in photoshop
on a Mac in Photoshop CS - the descreen checkbox is greyed out when
using the ColorPosi film setting.
Any ideas?
Thanks
Click to expand...


Yes Descreen will be greyed out for slide scanning. I get a lot of old
slide presentations too. What to do is use a very light Gausian Blur
filter, between 1 and 2 often works, but experiment, slides differ.
Then sharpen, using USM or Smart Sharpen, won't be perfect or even as
good as the descreening filter was used in the first place, but better
than what they have.

Tom
 
tomm42" ([email protected]) said:
Yes Descreen will be greyed out for slide scanning. I get a lot of old
slide presentations too. What to do is use a very light Gausian Blur
filter, between 1 and 2 often works, but experiment, slides differ.
Then sharpen, using USM or Smart Sharpen, won't be perfect or even as
good as the descreening filter was used in the first place, but better
than what they have.

Tom
Click to expand...


Poke around in your image editng software. I seem to recall a Remove
Moire utility in Paint Shop Pro. It doesn't work as well for me as what
comes with the scanner (which is basically a sophisticated blur), but it
is there. I'd wonder if you are going to have a problem anyway, as the
film needs to be pretty high-resolution to resolve the printed dots that
are going to cause moire problems.

Brendan
 
Hi
I've been given a load of slides to scan for inclusion in powerpoint
presentations. Unfortunately a lot of them are of photos in books
which are therefore halftone images.
In the scanner software - scangear CS for the Canon 8000f in photoshop
on a Mac in Photoshop CS - the descreen checkbox is greyed out when
using the ColorPosi film setting.
Any ideas?
Thanks
Click to expand...


I use the descreen filter plugin to remove any moire effects in
situations like that. I believe the filter name is DVP_LE.8BF. I
can't remember where I got it since I just transfer all my plugins to
the next version of PhotoShop when I get it, and that filter is
included in that bunch.
I did a Google search and it gave this address to get it
http://maxtor1.slu.edu.ph/Public/GRAPHICS/Photodlx/INSTALL/PLUGINS/?S=A
It's the very bottom one. With this filter you can do several
things....remove moire and remove graininess. Download it and place
it in your filter folder.
After you install it, go to "Filter"...."Noise"....and you will
see the "Remove Moire" filter.
To use it, I have found that you need to set the direction that
you want the moire to be removed. To do this, you need to go to the
circle that shows you the angle and click and hold one end of the line
that is in the middle of the circle. You need to rotate the line
until it is aligned with the lines of moire in the picture (the line
you are moving is parallel to the lines in the picture). Sometimes
there are horizontal and vertical lines, so you may need to do this
once for each set of lines.
All you need to do now is adjust the smoothness slider until the
lines disappear. Keep in mind that the picture will lose some clarity
when you do this, but keeping the smoothness slider control adjustment
to a minimum helps.
Anyway, I hope this helps...

Talker
 
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