Remove "random" noise

Question

I have a picture which was taken from a book and it's full of noise:

I tried to remove the noise manually but it is too difficult and takes a lot of time.
I noticed some webpages who attempt to treat the noise problem:
http://www.gimp.org/tutorials/Reducing_CCD_Noise/
http://www.gimp.org/tutorials/Selective_Gaussian_Blur/
But it is different than my type of noise.

Do you have any idea on how to remove this type of noise? With GIMP if possible.

It's not noise, it's compression artifacts and doesn't seem closely related to photography. — Olivier, May 25 '16 at 19:11
I'm voting to close this question as off-topic because this question is about cleaning up a graphic. Should be moved to graphicdesign.stackexchange.com — scottbb, May 25 '16 at 19:14
Possible duplicate of What are jpeg artifacts and what can be done about them? — mattdm, May 26 '16 at 03:47

score 5 · Accepted Answer · edited May 26 '16 at 03:43

What you are seeing in your example is not random noise. It is what is referred to as compression artifacts and is what happens when an image is compressed too much to make the file size smaller.

Instead of trying to use noise removal, simply use a levels or curves layer. Or even try just boosting the contrast. You have a white background and dark text and lines, and the noise is a light or middle grey, so any of those methods can be adjusted to remove the lighter tones and make them white.

For example, quickly using pixlr and boosting contrast, I get this result. I'm sure you can do better with GIMP and levels or curves

Using a curve:

Remove "random" noise

1 Answers1