RR, you're awesome. Rep to you for being so helpful!
edit: or not. I guess I already repped you recently...
Bryan Ray, visual effects artist
http://www.bryanray.name
Rob has sent some of the worst parts of the line ridged areas over. Although I have posted the full results back, here are some small swatches of the areas and how they were modified. I hope this helps. Some of the areas had some severe lines on them which practically obliterated the underlying features. Using a spatial filter will always destroy some of these features but with the hope that it will destroy the unwanted bits more and thus raise the overall signal to noise quality of an image. Some sorts of badness are really hard to separate from the good so thats when it fails to achieve a good result. Other times its brilliant. I think the best is for things like removing halftone from images where the unwanted bit is very regular and at a significantly different frequency from the good part of the image. These images had a mix where sometimes it worked better than others. You can judge for yourself tho.
I'm impressed!
I tried the second swatch using the GIMP using the FFT plugin.
I used a thresholded then blurred copy of the frequency domain image as a mask on a blurred copy of the frequency domain image.
I think I overdid it
Here is your swatch, with my effort at the bottom:
I've used this plugin to remove screening noise from images before. In case anyone wants to try, here is a link to wikibooks explaining how to remove coherent noise using GIMP and here is the link to the fft plugin I used.
-Rob A>
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That sounds like a similar process to what I did on mine. Its probable that Gimp has exactly the same process built into it. I would advise people to try it as sometimes, for the right instances, it can be miraculous. Your result is very good indeed. The only difference is probably some slight different tweaking in the filter image used. I thought somebody said that PS had it but at least I know Gimp has this for sure now.
That is amazing! This will be very helpful for the odd FT map which requires redoing. Any chance that it can be posted in the tutorial section for easy reference?