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I tried a few times to scan newspaper articles, but the images I got were always blotchy and with bad colors, sort of like this:
Sometimes I see some really good scans, like this:
What is the trick to get such good results? Do I need a high-quality scanner, or some good Photoshop filters?
If there is something I can do using free tools, that would be awesome.
itsadok
Posted 2009-07-21T14:47:51.960
Reputation: 1 560
10
A quick fix I do is to compensate for the low quality paper and printing, by adjusting the 'white point' and 'black point', efectively increasing the overall tonal contrast of the image.
Looking at your first example, the lightest parts of the image -- unprinted paper -- are actually a light grey and the darkest -- 'black' ink -- are a mid grey. And there's "blotchiness" in the lightest areas caused by the texture of the paper. One accepts this when viewing the original on paper, but not when viewing on screen, or when reproduced in higher quality print.
In Photoshop (sorry, not familiar with the Gimp, but I'm sure it's a similar process), I add a Levels adjustment layer to avoid altering the original pixel values, and then use the white point and black point sliders to "clip" the lightest and darkest points of the image to pure white and black. There's are eyedropper tools in the dialog for setting these points by sampling from the image, but it's easier to adjust the sliders manually.
Depending on context, I might add the paper colour back in as a a very light grey underlying layer, then set the scan layer's blending mode to "Multiply". This is essential if the original is printed on coloured paper, like the Financial Times.
e100
Posted 2009-07-21T14:47:51.960
Reputation: 1 078
You're absolutely right, in Gimp I just use contrast and then sometimes adjust the definition with a sharpness filter or unsharp mask. Working with levels is a bit more intensive, I often use the Quick Mask to selectively enhance certain areas of the image. The quality of the scanner isn't that important if you're making images for web work, everything on the web is lo-res, but if you want scans for print, you'll have to invest. – Ele Munjeli – 2011-08-11T18:54:45.107
It's also a good idea to scan the newspaper/magazine at an angle, to reduce the Moiré effect. – paradroid – 2012-12-12T07:53:58.337
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its old school, but put a sheet of black paper behind the newspaper. A lot of the issues are caused by the fact that newsprint is thin poor quality paper. The scanner sees the front and the back of the page at the same time. Black paper matches the black ink and makes the "back" side of the newsprint disappear.
Jim C
Posted 2009-07-21T14:47:51.960
Reputation: 1 748
1OP @itsadok did you try this, did it work? – Dan Rosenstark – 2011-08-11T17:04:28.327
This makes sense, since newspaper is so transparent, whereas the magazine isn't so transparent, so it works a lot better. +1 for simple fixes! – studiohack – 2012-12-12T07:28:41.310
Never underestimate the power of a simple analog solution! – Ilari Kajaste – 2009-12-04T07:58:53.293
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It's fairly tricky to scan halftone-dithered images from newspapers without a bit of background as to what's going on with the dots.
I suggest you have a look at this article.
For best quality, you basically choose the right resolution (the same as the print) and scan using a descreening filter (often available in your scanner software). You can then apply a despeckling filter (like median) to remove most of the remaining artefacts.
Ant
Posted 2009-07-21T14:47:51.960
Reputation: 714
0
Jim's tip of using a black paper behind the newspaper is very useful. In my opinion, any not too too old scanners are good enough to scan newspapers. The main problem is that newspaper is printed in low quality on poor quality paper comparing with photos. This problem can be resolved by software like photoshop.
did you finally find out what the problem was? – Lazer – 2009-09-23T10:35:41.233
I understand we are talking about scanner. But, has anyone tried using a digital camera instead ? – None – 2012-12-12T07:08:19.173
Off course the quality of the scanner will determine the quality of the pictures to some extend. You can always fix the quality with something like Photoshop, but a bad scanner will most likely always give bad pictures. What are you using right now? Scanner + Software – Ivo Flipse – 2009-07-21T14:58:21.023