MATLAB TUTORIAL TEN

To perform Wavelet Transform on given image using Matlab.

clc;

close;

[namefile,pathname]=uigetfile({'*.bmp;*.tif;*.tiff;*.jpg;*.jpeg;*.gif','IMAGE Files;(*.bmp,*.tif,*.tiff,*.jpg,*.jpeg,*.gif)'},'Chose GrayScale Image');

X=imread(strcat(pathname,namefile));

if(size(X,3)==3)

X=rgb2gray(X);

end

imshow(X); title('Original RGB image converted to Grayscale image');

% Perform wavelet decomposition at level 2.

[c,s] = wavedec2(X,2,'db1');

figure;

plot(c) , title('Wavelet decomposition data generated by wavedec2');

figure;

%Calculate first level approx. and detail components

ca1 = appcoef2(c,s,'db1',1);

subplot(2,2,1);imshow(ca1,[]);title('First level approx');

ch1 = detcoef2('h',c,s,1);

subplot(2,2,2);imshow(ch1,[]);title('First level horixontal detail');

cv1 = detcoef2('v',c,s,1);

subplot(2,2,3);imshow(cv1,[]);title('First level vertical detail');

cd1 = detcoef2('d',c,s,1);

subplot(2,2,4);imshow(cd1,[]);title('First level diagonal detail');

%Calculate second level approx. and detail components

figure;

ca2 = appcoef2(c,s,'db1',2);

subplot(2,2,1);imshow(ca2,[]);title('Second level approx');

ch2 = detcoef2('h',c,s,2);

subplot(2,2,2);imshow(ch2,[]);title('Second level horizontal detail');

cv2 = detcoef2('v',c,s,2);

subplot(2,2,3);imshow(cv2,[]);title('Second level vertical detail');

cd2 = detcoef2('d',c,s,2);

subplot(2,2,4);imshow(cd2,[]);title('Second level diagonal detail');

figure;

a0 = waverec2(c,s,'db1');

imshow(a0,[]);title('Reconstructed image using inverse wavelet transform');