problem in using the toolbox.

hi, i am having a very different problem. i am not able to find the solution anywhere. i want to do the wavelet decompostion using the toolbox. but i don't know how to link its output with my main program. my final year project is "brain tumor detection" and one of the steps involved is Wavelet Decomposition. Plz help me out on this problem.

Answer 1

[Wayne King]

Hi Shivani, I'm assuming from your post that you are interested in the 2-D or 3-D discrete wavelet transform.

I recommend you use wavedec2() or wavedec3 (for 3-D) to decompose your images and then use detcoef2() and appcoef2() to obtain the matrices corresponding to the approximation image, vertical, horizontal, and diagonal details in the 2-D. For 3D, you extract them directly from the output.

For example (2-D):

load woman;
[C,S] = wavedec2(X,3,'bior3.5');
% obtain level 1 horizontal, vertical, and diagonal details
[H,V,D] = detcoef2('all',C,S,1);

The matrices H,V,and D contain the horizontal, vertical, and diagonal details.

For 3-D:

X = reshape(1:512,8,8,8);
wdec = wavedec3(X,1,'db1','mode','per');
HHL = wdec.dec{4};

The ordering of the filtering operations in the cell array wdec.dec is documented on the wavedec3 reference page.