[REQ] Scanning tips: how to clean scanned images (11)

1 Name: Random Anonymous 2005-03-13 02:26 ID:DsnnTmsV

I'd like that people who know how to clean scanned images to explain here what are your methods for cleaning scans, taking into account that not all scanners have a Descreen function to get rid of the moire. Here's what I do (PSP8):

1.- Scan at 600dpi
2.- Moire Pattern Removal: Fine details at 2, Remove bands 0
3.- Edge Preserving Smooth: Amount of smoothing 6 (depends on detail level of the source)
4.- Automatic Color Balance: 6500 preset (I use this filter because the Moire Pattern Removal changes/messes the colors in some of the scans)
5.- Resize: 50%, keeping the aspect, Smart Size

Of course, this is not true for all types of scans, just for printed material. And even being printed material, you may need to adjust some settings from scan to scan.

Please post your own techniques and the applications you use to do the job. Thanks.

2 Name: Random Anonymous 2005-03-13 03:15 ID:GQv5wjxg

3 Name: Random Anonymous 2005-03-13 05:35 ID:Heaven

here's what i do:

  1. scan at 1200 dpi
  2. adjust color balance with the gimp or psp 8

of course, the scanner i use is probably a lot better than most...

4 Name: !WAHa.06x36 2005-03-13 12:48 ID:NG++ghmT

For black-and-white pages of comics, nothing beats scanning at high res, applying a threshold, and scaling down. If you want to be fancy, edit the scan after thresholding to remove single pixels and other scratches.

5 Name: Random Anonymous 2005-03-13 18:21 ID:GQv5wjxg

Probably well-known but worth repeating:

Find yourself a piece of black paper or cardboard and slip this in behind everything you scan. Otherwise things printed on the other side of the page and the next page(s) will show through. Makes a huge difference, especially with thin paper like magazine pages.

6 Name: !WAHa.06x36 2005-03-13 23:43 ID:NG++ghmT

>>5

If you do the threshold trick I mentioned earlier, that is not necessary. Of coure, that only works for black-and-white.

7 Name: Random Anonymous 2005-03-14 03:53 ID:GQv5wjxg

>>6
It still helps a bit if there's less noise to start with.
Is threshold the same thing as levels adjustment?

8 Name: Random Anonymous 2005-03-14 06:17 ID:DsnnTmsV

1200dpi is not an option in this case, because the max optical resolution of my scanner is 600dpi.

9 Name: !WAHa.06x36 2005-03-15 15:56 ID:NG++ghmT

>>7

It is, if you set both limits of the level adjustment to the same value. A threshold just turns every people above a certain brightness white, and the rest black. Which is how things are printed in the first place.

10 Name: Random Anonymous 2005-03-23 20:18 ID:DsnnTmsV

I've been testing with magazines, but in every one of them, I see the pattern clearly. If I get close to the magazine paper, I notice it too, so I guess it's not the scanner's fault. Any tips to kill the moire pattern are welcome.

11 Name: dmpk2k!hinhT6kz2E 2005-03-24 00:57 ID:aPVJyYn1

If you have a good high-res color scan, unsharp mask then downsizing helps.

If the scan is bad, sorry. Garbage in, garbage out.

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