DWT2 on an RGB image.

Hi,

I am trying to run DWT2 in RGB images as a pre-processing on images, i think this will help me in reducing the time consumption, but there is something wrong in the output, the first image appears as a blank image with small black points, what is the wrong in this code, please i need your help:

file = dir(fullfile('C:\Users\Documents\Work\image.orig','*.jpg'));% JPG Files ONLY

file = file(~[file.isdir]);

for k = 1

    disp(fullfile('C:\Users\Documents\Work\image.orig',(file(k).name)));

    image{k}= imread(fullfile('C:\Users\Documents\Work\image.orig',(file(k).name)));

    [cA1,cH1,cV1,cD1]=dwt2(image{k}, 'db1');

    figure(k),
    subplot(2,2,1); imshow(cA1);
    subplot(2,2,2); imshow(cH1);
    subplot(2,2,3); imshow(cV1);
    subplot(2,2,4); imshow(cD1);
end

Thank you in advance.

Answer 1

[Wayne King]

Hi Jessica, I suspect your problem is just scaling. What is your input image data type (uint8?)

For example:

load jellyfish256
[cA1,cH1,cV1,cD1] = dwt2(X,'db1','mode','per');
% the following does not display well
imshow(cA1);

But

imshow(cA1/255)

[Jessica]

yes it is unit 8 image

[Jessica]

Thank you it worked correctly