Removing Mesh/net from image - Fast Fourier Transform will work

seneca77 · June 24, 2007

Finally de-lurking...with a problem I can't seem to fix. I went to a professional baseball game and had great seats behind home plate, just down the third base line. However, I had to shoot through the net that is strung up to protect the fans from an errant foul ball. Other than some very tedious cloning, is there an easier way to get rid of the net? Layer masks, messing around with blending modes...? A sample photo is below.

I have PS CS3 running on a Mac. Thanks to all in advance!

- Bob Harrison
Tampa, FL

pyrtek · June 25, 2007

What you need is a frequency domain filter. There are many Photoshop
plugins implementing an FDF out there. Here's one.

BinaryFx · June 25, 2007

pyrtek wrote:

What you need is a frequency domain filter. There are many Photoshop
plugins implementing an FDF out there. Here's one.

I agree. There was a very good thread about FFT once...let me see if I can find it via a search!

http://retouchpro.com/tutorials/index.php?m=show&id=185
http://www.retouchpro.com/forums/image-help/10660-fft-golf-balls.html
http://www.pages.drexel.edu/%7Eavc25/archive.htm#FFT
http://www.skeller.ch/ps/fft_action.php
http://rsb.info.nih.gov/ij/docs/examples/FFT/

Here is a very quick 30 second first attempt example using a PC FFT filter in Photoshop, much better results would be obtained with repeated efforts (using black insted of gray when painting, using circle brush spot instead of square?) - while still being quicker and offering better quality than using regular Photoshop methods. I will keep experimenting and may post a better effort later, this is my first use of FFT (putting theory to first use, thanks to the OP from seneca77).

Regards,

Stephen Marsh.
http://members.ozemail.com.au/~binaryfx/

BinaryFx · June 25, 2007

This took about 1min-1.5min and is better than the first effort. The work I did in the frequency domain is shown to the right (simple hard black brush spot over each of the original frequency 'hot spots' radiating from the centre point).

FFT filtering really is magic for this type of retouching work!

Edit: I forgot to 'pad out' my document edges with a thick gray border before FFT filtering, which may have helped a bit too if I remember things right (so still not my best FFT effort, but much better for a second stab).

Stephen Marsh.
http://members.ozemail.com.au/~binaryfx/

Richard · June 25, 2007

That is simply amazing. Thanks for the information.

Regards.

pathfinder · June 25, 2007

You just never know when something will blow your socks off. Very interesting thread, and the links explain the FFT well. Very interesting.

Removing Mesh/net from image - Fast Fourier Transform will work

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