Filtering pada Image menggunakan LPF

clc;

close all;

% Lowpass Filter Design

LowpassFilter = Fspecial('gaussian', [11 11], 1.3);

%  fft of lowpass filter

       LowpassFilterSpectrum = fftshift(fft2(LowpassFilter, intRows, intCols));

% Figure

   figure('Name', 'Lowpass Filter', 'NumberTitle', 'off', 'MenuBar', 'none');

    colormap('gray');

    subplot(1,2,1);

    imagesc(log10(1+abs(LowpassFilterSpectrum)));

    title('Log Magnitude');

    subplot(1,2,2);

    imagesc(angle(LowpassFilterSpectrum));

    title('Phase');

   

 % filtering  

    imgLennaFiltered = LowpassFilterSpectrum .* imgLennaSpectrum;

    figure('Name', 'Lowpass Filtered Image', 'NumberTitle', 'off', 'MenuBar', 'none');

    colormap('gray');

    subplot(2,2,1);

    imagesc(log10(1+abs(imgLennaFiltered)));

    title('Log Magnitude');

    subplot(2,2,2);

    imagesc(angle(imgLennaFiltered));

    title('Phase');

  % Inverse FFT

    subplot(2,2,3);

    imgLennaLowpassFiltered = abs(ifft2(imgLennaFiltered));

    imgLennaLowpassFiltered = circshift(imgLennaLowpassFiltered,[-1.*floor(length(LowpassFilter)/2) -1.*floor(length(LowpassFilter)/2)]);

    imagesc(imgLennaLowpassFiltered);

    title('Inverse FFT of Lowpass Filtered Image');

   

    subplot(2,2,3);

    imagesc(imgLennaPhase);

    title('Phase of FFT of lenna.gif');

   

    subplot(2,2,4);

    imagesc(imgLennaInverseFFT);

    title('Inverse fft');