Index exceeds matrix dimensions.

Hello, I have an error :( Index exceeds matrix dimensions.

clc;
clear;
close all;
I = imread('C:\Users\Pictures\sgs.jpg');
    I = rgb2gray(I);
    [m , n ] = size(I);
    MaxI = 0;
    for i = 1:n
        for j = 1:m
            if (I(i,j) > MaxI)
                MaxI = I(i,j);
            end
       end
    end

Answer 1

[Adam]

[m , n ] = size(I);

gives you the number of rows and columns in m and n respectively.

You then loop i up to n and j up to m, but use

I(i,j)

which is switching round the rows with the columns so unless you have a square image you will see this error.