Find matching small matrix in larger matrix

Hi,

I need to find if a binary logical matrix is somewhere in a larger binary matrix.

I am looking for specific patterns like:

pat = [0 0 1; 0 1 0; 0 0 0]

if it is somewhere in a larger matrix por example:

As you can see the patter is found with its center at r=137, c=810

I need a way to get the position (if there is) of these submatrix in the larger matrix.

Any help?

Thanks

Answer 1

[Michael]

An admittedly brute force approach, but Matlab doesn't have a built in method for finding patterns in an array/matrix (at least it didn't back in 2017).

[blm_rows, blm_cols] = size(binarylogicalmatrix);
pat = [0 0 1; 0 1 0; 0 0 0];
[pat_rows, pat_cols] = size(pat);
for i = 1:blm_rows-pat_rows+1
    for j = 1:blm_cols-pat_cols+1
        subblm = binarylogicalmatrix(i:i+pat_rows-1,j:j+pat_cols-1)
        if subblm == pat
            disp('Pattern Found!')
            found_row = i;
            found_col = j;
            break
        end
    end
end

[Luis Rosety]

Thanks!

Even though I was convinced there was some magical function, your "brute force approach" solves my problem!