Moiring effect on photos

JohnGG wrote on 5/18/2006, 4:08 PM
We scan newspaper photos on an HP scanner then import to PhotoShop for cropping. Pics are OK at this point.

Then we import to Vegas 6. Pics still look OK in the clip bin.

However, once we put them on the time line and view them in the Preview window complex moire patterns appear. These patterns change with different scanning resolutions and different settings of the Preview parameters but are always present to varying degrees. Reduced interlace flicker control had no effect.

Rendering the timeline and transfering to a videoi monitor still shows the moiring. Exporting the rendered Vegas video to Moviemaker shows the moiring really bad.

If we transfer the scanned pics from PhotoShop to Moviemaker direct, they appear without any moiring.

We tried putting transparent sheets in front of the pictures on the scanner and also black backing to no effect.

How can we stop the moiring on Vegas 6?

Comments

JohnGG wrote on 5/18/2006, 4:35 PM
Correction to my earlier post:

Clips in the clip bin have the same moired appearance as when on the time line. Sorry about that.
Paul_Holmes wrote on 5/18/2006, 5:54 PM
Well, I just did a photo movie in which one picture had an extreme moired background, everything vibrating. I used the Linear Blur at about 232 and a setting of about .02 (or .002 -- can't remember the increments off the top of my head). Beyond 2 it gets too blurry for my taste. It didn't remove it completely, but almost, and made it very acceptable.
farss wrote on 5/18/2006, 6:02 PM
It's quite possible that part of the problem is the screen used in the printing process, does your scanner have the ability to descreen scanned images, this may help.

Alternatively puts a copy of the still on an upper track, add a tiny amount of Gaussian Blur, Vertical .001 or .002 Horizontal = 0. Now use the Cookie Cutter on the top track to cutaway all but the problem area(s).


This will preserve as much resolution as possible while removing the moire / line twitter.

However I think your problem is most likely the screen, descreening first would be your best approach or else use PSs Smart Blur.

Bob.

Serena wrote on 5/18/2006, 6:18 PM
Recently had this problem in digital photographs of a printed photos -- moire fringing through interaction between printing screen and camera pixel array. Used gausssian blurring in Photoshop to calm it all down. Probably better to fix the problem before putting images into Vegas, as Farss has said.
Laurence wrote on 5/18/2006, 6:27 PM
What I do is scan at really 1200 dpi resolution, zoom in to see the actual pixels, then use a light gaussian blur to blur to the point where the dot pattern disappears. Then I resize down to 300 dpi and save the file as a png. There are other much faster ways to do it, but this gives me the best quality.

I often also separate the scanned pages into layers with things like printed photos and textured backrounds on separate layers from the text. The text usually needs no gaussian blur at all whereas the photos and textured patterns benefit immensely.

johnmeyer wrote on 5/18/2006, 6:43 PM
Bob (farss) is correct: You must use scanning software that descreens (removes the dots from the newspaper/magazine halftone process). If you don't, you will get moire, for sure.

Vuescan has this function. Works extremely well.
dand9959 wrote on 5/19/2006, 7:54 AM
In my software (whatever came with the Canon Canoscan), the setting is called "Magazine".

I was having awful problems scanning an old newspaper photo...it was all dots! I finally tried the Magazine setting on a whim (who reads manuals, anway?), and it worked beautifully.
Chienworks wrote on 5/19/2006, 8:39 AM
I use Laurence's method too, though i usually do my initial scan at 4800 or so. I find it preserves detail a bit better than the built-in descreening algorithms.