Version 2 (modified by benl, 5 years ago)



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


The main algorithm is at

The wrapper is at

Test Data is a standard test image.

lena.bmp lena-high2.bmp
Error: Macro Image(WikiStart:lena-high2-thumb.jpg) failed
Attachment 'wiki:WikiStart: lena-high2-thumb.jpg' does not exist.
full size full size


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