Fourier Transform Plug-in - get rid of "newsprint dots"

[-default]

Here's a link to an interesting FFT thread, this time on dgrin.com:
http://www.dgrin.com/showthread.php?t=64775

[mikemeister_admin]

Here's a link to an interesting FFT thread, this time on dgrin.com:
http://www.dgrin.com/showthread.php?t=64775

thanks mike,

i wil look at it.
till now I am completely forgotten the sequence, but it is still on this site.

frits

[joann]

Mike,
What do you mean by"and run the  inverse FFT plugin"?
JoAnn Head

[-default]

Hi JoAnn,

I meant to run the FFT plugin, with the inverse mode selected.  You can download the plugin here:
http://home.planet.nl/~ber03728/4N6site/improc/fftplugin/howto.htm

This is still the best way I've found to remove halftone dots.  Please let me know if you have any more questions.

Mike

[-default]

Here's an article posted by Chris Nicola with additional information and links on using this excellent plugin. - Mike
I read with great interest Mike Russell's comments on how to use a free forensic Fourier Transformation tool to remove news print dots, moire patterns and other image imperfections. The good news is this method works with Photoshop Elements. There are at least three methods to use the FFT technique with PSE.

Notice in the examples in the link below how the halftone dots and image imperfections can be removed.
http://www.curvemeister.com/forum/index.php/topic,62.0.html

Here is my own example of how paper texture can be removed. (In Files section A Contest Files/FFT Comparison)
http://f1.grp.yahoofs.com/v1/kJofTIBfJyseqXGA-Jf6WmD5VXtQmZdBUqyv6zQ-wQlN-kyFHKgiwP0zrl7VI8CUc4nU9gTD1SpYfTA5VFpblpYfoQqEK-TrgIu2e_I/A__Group%20Contest/FFT%20Comparison.jpg

Notice in this example how the baseball netting can be removed in the picture:
http://www.dgrin.com/showthread.php?t=64775

More examples of FFT Filtering: (Fast Fourier Transformation)
http://rsb.info.nih.gov/ij/docs/examples/FFT/

An action and also a Brush for the full PS can be downloaded here:
http://www.skeller.ch/ps/fft_action.php

This is the site that provides the Free FFT filters that can be used in PSE and many other applications.
http://home.planet.nl/~ber03728/4N6site/improc/fftplugin/getit.htm

Here is the tutorial for use with the Full PS:
http://home.planet.nl/~ber03728/4N6site/improc/fftplugin/howto.htm

Another tutorial showing how the paper texture can be removed using the full PS
http://retouchpro.com/tutorials/index.php?m=show&id=185


Well, how does it work with PSE? In the future I hope to post a tutorial in the files section explaining the three methods with screenshots.
In the meantime I studied Mike Russell's method and posted some screenshots (please see below). I wish to thank Mike Russell and Greg Groess for helping me to understand this very useful technique and of course Alex Chirokov and the site http://www.4n6site.com/ for providing the FFT plug in.

Method 1 with PSE
Please see only the last post in this link for the final solution with screenshots:
http://www.curvemeister.com/forum/index.php/topic,3054.0.html

1 Download the two plug-ins FFT a iFFT from:
http://home.planet.nl/~ber03728/4N6site/improc/fftplugin/getit.htm
Unzip the zip file and then place the two files in your plug in folder.

2 Open the test image which can be downloaded from:
http://home.planet.nl/~ber03728/4N6site/improc/fftplugin/howto.htm
It is a PNG file so convert the mode to RGB for FFT to work. (Image/Mode/RGB)

3 For the sake of the demonstration I Introduced a green tint to the test file. Right click the original background and select duplicate layer. Please see Screenshot 1

4 Go to filters and under "Fourier Transform", apply the FFT filter to the original Backgroud layer on the bottom. Note FFT does not work on a true layer so thats why it has to be applied to the original Background which has no transparency information. It will not work on the copy above it which is a true layer. Please see Screenshot 2.

5  Apply a levels adjustment to the Background layer and as Mike says select the blue channel from te drop down menu and drag the output slider on the bottom right all the way to the far left so the blue output level is set to zero. Do the same with the Green output slider. The result of the FFT image will look red. Please see Screenshot 3.

6 Click the foreground colour box and select Cyan by typing R 0, B 255, G 255. Select the brush tool and set the brush mode to multiply from the top menu and carefully paint out the stars and diagonal lines but leave the central point of light intact. Please see Screenshot 3 and also the link below for more details on the parts to paint out.

http://home.planet.nl/~ber03728/4N6site/improc/fftplugin/howto.htm

7 Click on the original background layer and apply inverse Fourier Transform iFFT. The resulting Image will look red. Later you can delete the layers adjustment. Please see  Screenshot 4 and also screensot 5 with the layers adjustment deleted.

8 The problem at this point is the image has lost its colour due to the FFT. If it was originally a black and white image we could leave it as it is. However to bring back the colour in a coloured image another step is needed. Right click the original background layer to which FFT and iFFT has been applied and right click and convert to a layer. Then move the black and white image over the copy of the original image (Green) which still has its colour. Set the blend mode to luminosiy and switch on all the eyes. The colour has now returned. As a finishing touch apply a Gaussian blur of about 2 to the lower coloured image.  (Filter/Blur/Gaussian Blur) This will not blur the resulting image because the details come from the image on top and the lower image just provides the colour when the blend mode is set to luminosity. Please see  Screenshot 6.


Method 2 with PSE If the Elements Plus plug In has been installed
Go through steps 1-4 for method 1
Instead of using step 5 click on the Icon in Elements plus that allows you to use channels and click on the red channel.
Click here to see how to do this with the latest version for PSE8
http://elementsplus.net/v2/en/color_channels.htm
Make sure "show inactive channels is unchecked."

Proceed with steps 6 to paint out the unwanted parts of the image using a Cyan brush set to multiply.

Click on the Elements plus plug in and convert back to RGB before using inverse iFFT filter

Finish with step 8.

Method 3 Using PSE and The Image Analyzer Programme:
First Google "Image Analyzer " and download the free standalone programe.

A- Run Image Analyser and go to file/Open to open the image

B- Use Operations/Transformations/Fourier Transform

C- Click on the eraser tool and remove all the points and starbursts of light except the central point and star.

D- Go to Operations/Transformations/InverseFourier Transform

E- File /Save as to save the image with a new file name. This image willbe black and white.

F- To restore the colour open the image in PSE and use point 8 in method 1


Although this is a very powerful technique, it requires some practice to get the hang of it and it does not miraculously clean up all types of images perfectly. Also you might notice that the free FFT plug in has some limitations. It may introduce a bit of noise which may not be too critical as we are working with problematic images to start with. It does not work too well along the edges of an image so introducing a thick grey border, running the FFT and then removing the border may help. I tried using a border with one image and it didn't make much difference in my opinion. Some professional FFT tools ($) overcome these limitations.

I am sure many of you will find this technique useful for cleaning up some types of images. Have fun!

Kind Regards

Chris

[pictus]

For Windows/Photoshop x64 version http://www.retouchpro.com/forums/software/33084-here-fft-64-bit-photoshop.html

[-default]

Thanks, Pictus!

[Doug.S]

For me the above link to FFT x64 version is broken

Any news on where to find same (maybe another source)

Any news on FFT working with CS6 or CC?

[ggroess]

Found this link on the Retouch Pro site.

I was able to get it...

http://dl.dropbox.com/u/39521592/FFT.zip

Greg

[kenneth f. taylor]

the address before step 7 gives 'page not found' upon trying to access the 'how to' info; apparently there are missing diacriticals in the string - a tilde, i think . . . can anyone come up with the correct address? the info posited appears to be what i might want - thanks in anticipation