Version 2 (modified by 14 years ago) (diff) | ,
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fft2d-highpass
Applies a highpass to a BMP image. The first argument is the lower cutoff frequency.
Each of the RGB channels is converted to the frequency domain, the lower frequencies are set to zero, then the channels are converted back to the image domain.
repa-fft2d-highpass 2 lena.bmp lena-high2.bmp
Code
The main algorithm is at http://code.haskell.org/repa/repa-stable/repa-algorithms/Data/Array/Repa/Algorithms/FFT.hs
The wrapper is at http://code.haskell.org/repa/repa-stable/repa-examples/FFT/src/HighPass/Main.hs
Test Data
http://en.wikipedia.org/wiki/Lenna is a standard test image.
lena.bmp | lena-high2.bmp |
full size | full size |
Runtime
Compiled with GHC 6.13.20100309. 512x512 image.
Running on a Intel i7 iMac.
Threads | Time(s) |
1 | 24.81 |
2 | 13.37 |
3 | 10.4 |
4 | 7.79 |
5 | 8.24 |
6 | 7.25 |
7 | 6.87 |
8 | 6.58 |
Attachments (2)
- lena-thumb.jpg (6.6 KB) - added by 14 years ago.
- lena-high2-thumb.jpg (5.6 KB) - added by 14 years ago.
Download all attachments as: .zip