Introduction
FFT Artisti is a program that removes pattern noise from images (jpg, tif, png and bmp).The program uses the Fast Fourier Transform (FFT), convolution low-pass filters in frequency domain or/and direct frequency deleting to eliminate the pattern noise.
How much is it?
FFT Artisti is free of charge.The Fourier transform
The Fourier transform is a mathematical tool used to transfer an image from spatial domain to frequency domain.In the frequency domain we can view the power spectrum of the image, that indicates how much a frequency participates in the image construction.
| The image | The power spectrum of the image |
 |
 |
In the center of the power spectrum (the bright star) there is the low frequency information of the image (the solid color areas of the image) and in the edges of the power spectrum there is the information of the high frequencies (the details of the image). The white color indicates that a frequency participates a lot in image construction, the black color indicates that a frequency is missing. Of course low frequencies are more common in any image and for that reason in the center of the image there is the bright white star.
If the image is smooth like the image above, the power spectrum is smooth as well.
If it contains pattern noise then there are stars and lines in other places and not only in the center of the power spectrum. These stars and lines represent the frequencies of the pattern noise and they indicate that there is strong existence of this noise in the image.
| The noisy image (printed on grained paper of '70s) |
The power spectrum of the noisy image |
 |
 |
With FFT Artisti the user can delete the extra frequencies (stars) of the pattern noise directly. After that, the pattern noise has eliminated from the image without losing the details (the high frequencies) of the image.
| The processed power spectrum | The restored image |
 |
 |
The user interface
| The Image View (original and pocessed image) |
 |
| The Power Spectrum View (red, green and blue channel) |
 |
System Requirements
Fourier is an aristocrat and loves fast computers, large amounts of memory and 64 bit systems.But he was never be a snob and he deigns the rest of the systems as well.
- MS Windows 10/8.1/8.0/7/Vista or XP (32 or 64 bit)
- Intel i3 1.3GHz (or better)
- 2GB memory (the more, the better)
Examples
 |
| (Click to enlarge) |
 |
| (Click to enlarge) |
 |
| (Click to enlarge) |