How increase the value of each cell from 256*256 to 576*720

function [DifferenceStatistic] = jfDStatsN(M) 

dVEC(size(M, 1))= 0; 

lvl = (size(M, 1)^2); 

for i = 1:size(M, 1) 

      for j = 1:size(M, 2) 

          dVEC(abs(i - j) + 1) = dVEC(abs(i - j) + 1) + double(M(i,j));   

      end 
  end 

end

. . .

it gives me this error

Attempted to access dVEC(577); index out of bounds because numel(dVEC)=576.
Error in jfDStatsN (line 12)
        dVEC(abs(i - j) + 1) = dVEC(abs(i - j) + 1) + double(M(i,j));

[Geoff Hayes]

Bajdar - should dVEC be an 1-D array or a 2-D array (matrix)? You seem to be initializing it as a matrix but are accessing elements within it as if it is an array. This is fine so long as this is what you intend to do.

As for increasing the size of the array, how is 576x720 related to the dimensions of your M matrix?

[Bajdar Nour]

Dear @Geoff Hayes maybe I did not clarify it well, sorry for that..let me ask in another way, M is an image (576X720 uint8), when I run the code it gives me the above error that I mentioned?

[Geoff Hayes]

Bajdar - ok but what should dVEC be - an array or 576x720 matrix? What are you trying to accomplish with the above code?

[Bajdar Nour]

Dear @Geoff dVEC is 576x720 matrix,,I want to extract some features on 576x720 images..but this code is worked only when M is square dimensions(512X512 or 456X456 just for example), otherwise is not working

[Guillaume]

Maybe the code in the question has been modified, but as it is now, the code initialises dVEC as a 1 x W vector, with W the height of the input matrix M. If the width of the M matrix is greater than twice its height then the code will indeed error.

It's difficult to know what is valid in the code in the question since the none of variables created in the function match the function output variable.

Answer 1

[Guillaume]

If the intent is to calculate the sum of the diagonals of the matrix (corresponding upper and lower diagonals being sum together), then this can be achieved simply with:

    indices = toeplitz(1:size(M, 1), 1:size(M, 2));
    dVEC = accumarray(indices(:), M(:));