FFT Filtering
Here is one of the nifty things you may use fft filtering for. The laser scanning confocal microscope scans along the X axis. If there is noise in the laser, then this shows up most dramatically in adjacent X axis scans. Filtering the frequency of the alternating X axis intensities cleans up the image.

FFT filtering example

Gilles Carpentier extracted the orginal 256x256 image from this composite image and attempted to reproduce the results. He also provides several macros for removing horizontal streaks.

The Image Processing Toolkit also does this in Photoshop.

Example contributed by Michael Cammer, Analytical Imaging Facility, Albert Einstein College of Medicine.

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