Moire and Photoshop... - Page 2

louiscar · December 25th, 2009, 09:16 PM

Quote:

Originally Posted by tuffy

Let me illustrate this:

1. your original scan

2. how it looks like on my screen (full of moire)

Interesting although I think the idea of scanning higher is to get enough pixels to reduced enough to get rid of the patterning.

Incidentally no.2 has no actual moire it's the hallftone pattern which you are seeing in this when interpolated causes an undesireable effect. However, of course naturally this is as undesirable as moire and needs to be removed. Moire when it appears is just an added pain and is of course caused by the halftone usually when sized down and sort of looks like a magnetic field when present.

Descreen is very effective as you've shown but sadly a lot of scanners do not have this option so one needs to effectively find a method of doing the same thing manually.

**DARPA** · December 28th, 2009, 10:18 PM

I was looking at those three images and I would have expected "descreen" to do more to image 3 if it was moire. There is a difference between image 1 and image 3 but I would consider the difference negligible.

Man, I wish I had discovered the Despeckle/Gaussian Blur approach years ago. I did nearly 5,000 scans without it and what I'm outputting now is superior in just about every way - size, clarity, etc - to what I was outputting then.

louiscar · December 29th, 2009, 01:40 AM

Quote:

Originally Posted by DARPA

.... what I'm outputting now is superior in just about every way - size, clarity, etc - to what I was outputting then.

Glad it's working for them, I know how you feel though. I've got a lot of scans that I did many years ago and wonder if I should do them all again now that I know more and have better tools.

**DARPA** · January 6th, 2010, 12:51 AM

Quote:

Originally Posted by louiscar

Glad it's working for them, I know how you feel though. I've got a lot of scans that I did many years ago and wonder if I should do them all again now that I know more and have better tools.

well since I sold off the bulk of the mags I've already scanned, rescanning is not an option. That said, there is one set of one mag that I still have that I may take a serious look at rescanning because it's my favorite SE loop...

**grlilgirls** · January 24th, 2010, 07:19 PM

I find that the 'scientific approach' to the scanning of printed material and moiré advocated in this thread:
http://vintage-erotica-forum.com/t54...-approach.html
actually works wonders.
It is counter-intuitive to deliberately blur the picture, but it gets rid of the dot pattern without losing any relevant information.
I use the procedure all the time scanning old mags, like here:
http://vintage-erotica-forum.com/t25...gs-shared.html
so check out the results,
jj

lenolaman · February 17th, 2010, 07:54 PM

After reading a bunch of your problems, this approach might help anyone out. I worked at a prep house for years and sometimes we had to scan preprinted images. Scan at full size, 8.5 x 11 at 600dpi. In Photoshop, res down your image using "image", "image size", resolution set at 300dpi with "resample image" box checked. This almost always gets rid of a pattern. Then you can resample again if needed. You can set up an "action" for this function, then you can "batch" this action for a group of scans. This might take some time but the results are pretty good.

**Dekoda** · July 11th, 2010, 03:17 AM

If you are running into moire problems, it's not Photoshop, it's the scanner. I know you didn't want to spend much on a scanner, but if your HP scanner doesn't have a de-screeen function, it would benefit you to get another scanner. I use a Canon 9950F, but that's no longer being manufactured. I think the replacement for it is the 8800.

Using this scanner will avoid moire and save you a lot of time. If you use the despeckle filter in Photoshop or the gaussian blur filter, while it might remove the moire effects, it also degrades the scan. The same thing happens when you scan at a high DPI and then resize it down. It might remove the moire, but the picture will lose some sharpness.

I have a plugin for Photoshop that will remove moire, but it still makes the picture look soft. I have used it on rare occasions, but I never do like the end result.

I have never used an HP scanner, so I don't know what it's software has in the way of de-screen functions, or how well they work. My Canon has an excellent de-screen function, and I have never had any moire problems since I started using this scanner.

December 28th, 2009, 10:18 PM	#12
DARPA Veteran Member Join Date: Mar 2008 Location: Trapped inside a scanner Posts: 3,503 Thanks: 4,331 Thanked 61,994 Times in 3,412 Posts	I was looking at those three images and I would have expected "descreen" to do more to image 3 if it was moire. There is a difference between image 1 and image 3 but I would consider the difference negligible. Man, I wish I had discovered the Despeckle/Gaussian Blur approach years ago. I did nearly 5,000 scans without it and what I'm outputting now is superior in just about every way - size, clarity, etc - to what I was outputting then. Last edited by DARPA; December 28th, 2009 at 10:23 PM..

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January 24th, 2010, 07:19 PM	#15
grlilgirls Veteran Member Join Date: Apr 2008 Posts: 1,674 Thanks: 11,615 Thanked 150,188 Times in 1,730 Posts	I find that the 'scientific approach' to the scanning of printed material and moiré advocated in this thread: http://vintage-erotica-forum.com/t54...-approach.html actually works wonders. It is counter-intuitive to deliberately blur the picture, but it gets rid of the dot pattern without losing any relevant information. I use the procedure all the time scanning old mags, like here: http://vintage-erotica-forum.com/t25...gs-shared.html so check out the results, jj

February 17th, 2010, 07:54 PM	#16
lenolaman Junior Member Join Date: Sep 2009 Posts: 4 Thanks: 2 Thanked 16 Times in 4 Posts	After reading a bunch of your problems, this approach might help anyone out. I worked at a prep house for years and sometimes we had to scan preprinted images. Scan at full size, 8.5 x 11 at 600dpi. In Photoshop, res down your image using "image", "image size", resolution set at 300dpi with "resample image" box checked. This almost always gets rid of a pattern. Then you can resample again if needed. You can set up an "action" for this function, then you can "batch" this action for a group of scans. This might take some time but the results are pretty good.

July 11th, 2010, 03:17 AM	#17
Dekoda Vintage Member Join Date: Jul 2010 Posts: 823 Thanks: 20 Thanked 24,261 Times in 822 Posts	If you are running into moire problems, it's not Photoshop, it's the scanner. I know you didn't want to spend much on a scanner, but if your HP scanner doesn't have a de-screeen function, it would benefit you to get another scanner. I use a Canon 9950F, but that's no longer being manufactured. I think the replacement for it is the 8800. Using this scanner will avoid moire and save you a lot of time. If you use the despeckle filter in Photoshop or the gaussian blur filter, while it might remove the moire effects, it also degrades the scan. The same thing happens when you scan at a high DPI and then resize it down. It might remove the moire, but the picture will lose some sharpness. I have a plugin for Photoshop that will remove moire, but it still makes the picture look soft. I have used it on rare occasions, but I never do like the end result. I have never used an HP scanner, so I don't know what it's software has in the way of de-screen functions, or how well they work. My Canon has an excellent de-screen function, and I have never had any moire problems since I started using this scanner.