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Arkadaşlar matlab da iki boyutlu alçak geçiren filtrenin açık kaynak kodu lazım

ilginiz için şimdiden teşekkürler...

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kolay gelsin...

imfft.m - Performs 2D FFT on an image and rearranges result to place low frequencies centrally.
function Y = imfft(X)
Y = fftshift(fft2(X));
imifft.m - Inverse imFFT.
function Y = imifft(X)
Y = abs(ifft2(ifftshift(X)));
immagphase.m - Displays magnitude and phase of a matrix containing imFFT information.
function immagphase(X)
subplot(121)
A = abs(X);
if min(min(A)) == 0
Y = mat2gray(log(A + 1e-7));
else
Y = mat2gray(log(A));
end
subimage([-1 1],[-1 1],Y)
title 'Magnitude'
subplot(122)
Y = mat2gray(angle(X));
subimage([-1 1],[-1 1],Y)
title 'Phase'
lowpassfilter.m - Creates lowpass Butterworth filter in two dimensions.
% LOWPASSFILTER - Constructs a low-pass butterworth filter.
%
% usage: f = lowpassfilter(sze, cutoff, n)
%
% where: sze is a two element vector specifying the size of filter
% to construct.
% cutoff is the cutoff frequency of the filter 0 - 0.5
% n is the order of the filter, the higher n is the sharper
% the transition is. (n must be an integer >= 1).
%
% The frequency origin of the returned filter is at the corners.
%
% See also: HIGHPASSFILTER, HIGHBOOSTFILTER, BANDPASSFILTER
%


function f = lowpassfilter(sze, cutoff, n)

if cutoff < 0 | cutoff > 0.5
error('cutoff frequency must be between 0 and 0.5');
end

if rem(n,1) ~= 0 | n < 1
error('n must be an integer >= 1');
end

% Modification
% Original code [rows, cols] = sze was not accepted by Matlab
rows = sze(1);
cols = sze(2);
% End Alteration

% X and Y matrices with ranges normalised to +/- 0.5
x = (ones(rows,1) * [1:cols] - (fix(cols/2)+1))/cols;
y = ([1:rows]' * ones(1,cols) - (fix(rows/2)+1))/rows;

radius = sqrt(x.^2 + y.^2); % A matrix with every pixel = radius relative to centre.

% Alteration
% Original code fftshifted the filter before output. Since
% imFFT and imIFFT already shift, the output should remain low-centered.
f = 1 ./ (1.0 + (radius ./ cutoff).^(2*n)); % The filter
% End Alteration

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Başa dön