how to divide an image to 4 equal parts and again divide those 4 images into another 4 parts and convert it to a matrix?

Hi,

I am doing a project where I want to divide an image first into 4 parts and based on the threshold criteria each part of the main image has to be again divided into another 4 parts and it should carry on till the dim is 1xn or nx1? (As my image is 24x124 it should be divided till 1xn)

I could first divide the image into 4 parts and store as a matrix, but further i am unable to divide each image into another four parts?

Here is my code:

load LTP54

ROI = ZI(37:60,949:1072);

[rows, columns] = size(ROI);

n = 2;

r = rows/n;

c = columns/n;

k = r/n;

l = c/n;

output(:,:,n^2) = zeros(r,c);

op(:,:,n^2) = zeros(k,l);

cnt = 1;

for i=1:n

   for j=1:n,

      output(:,:,cnt) = ROI((j-1)*r+1:j*r, (i-1)*c+1:i*c);

% I = output(:,:,cnt);

% op(:,:,cnt) = I(((j-1)*k+1:k*r), ((i-1)*l+1:i*l));

      cnt = cnt + 1;

   end

end

cnt1 = 1;

for i = 1:n

    for j = 1:n

    I = output(:,:,1);

    op(:,:,cnt1) = I(((j-1)*k+1:j*k), ((i-1)*l+1:i*l));

    cnt1 = cnt1+1;

    end

end

In the second for loop i am able to take only 1 part as my input and divide it into 4 parts, but not all 4 parts of the image.

Could any one help me with this?

Answer 1

[Image Analyst]

Sounds similar to what qtdecomp() (quadtree decomposition) does.

[Rahul Krishna]

ya, we have qtdecomp() function but it only works when the size is 2^m x 2^n or 2^n x 2^n or 2^n x 2^n but it doesn't work for other multiples of 2.

My image is having a matrix of 24x128 pixels. I am unable to use qtdecomp(). So i want to divide it by making a function of my own.

Thanks for your reply.