FFT adaptive lowpass filter.
function call:
[out_img1r,out_img1i]=vsg('FFTAdaptiveLP',in_img1r,in_img1i,thresh);
Arguments:
in_img1r
- input image, 3
channel RGB, 1 channel greyscale or binary image of the real FFT
coefficients.
in_img1i
- input image, 3 channel RGB, 1 channel greyscale or binary image of the
imaginary FFT coefficients.
Thresh
– a double which specifies a magnitude threshold, above which all input
image values will be kept. Below this value will have output pixels set
to 0.
Description:
The user defined
input limit is the cutoff frequency for the filter. Unlike the
low-pass filter which is based on the position of the filter in Fourier
space, this approach is dependent on the real and imaginary values of
all the data in the Fourier space.
out_img1r
– the output image values are the real FFT coefficients of the input
images, which have had a threshold applied to their values.
out_img1i
– the output image values are the imaginary FFT coefficients of the
input images, which have had a threshold applied to their values.
Example:
img = openimage('baboon.jpg');
[out_img1]=vsg('GreyScaler',img);
figure;image(uint8(out_img1));
[out_img1,out_img2]=vsg('FFT',out_img1);
[out_img1r,out_img1i]=vsg('FFTAdaptiveLP',out_img1,out_img2,0.3);
[out_img1]=vsg('InvFFT',out_img1r,out_img1i);
h=figure;image(uint8(out_img1));set(h,'Name','FFTAdaptiveLP');
For