Detection of square island in QRcode and output display using IF ELSE.

How to detect the square island shape in the QRcode without referring to the ARRAY workspace and if the square island shape is detected, output message will be shown as "QRcode".

Usually we check the array to find the pattern, but I do no want to use array at all because it will be more interesting if I just detect the shape using image processing using matlab language. Any ideas?