Assignment has more non-singleton rhs dimensions than non-singleton subscripts

My program get an error "Assignment has more non-singleton rhs dimensions than non-singleton subscripts" in line 21, which is "S (i, j, k) = Temp;" but I do not know how to fix it. My program is shown below:

function J = EE4206_Assignment3_Q1_StretchContrast (filename, MinGray, MaxGray)

A = filename;

I = imread (A);

I = im2double(I)*255;

[r c k] = size (I);

MinInput = min(min(I));

MaxInput = max(max(I));

S = ones (r, c, 3);

for i = 1 :r
    for j = 1 : c
        for k = 1 :3
            Temp = (MaxGray - MinGray).*(I(i, j, k) - MinInput)./(MaxInput - MinInput) + MinGray;
            S (i, j, k) = Temp;
        end
    end
end

J = image (S);

imshow (J);

Thank you !!!

Answer 1

[Matt Fig]

Please do not use this awful construct to find the global minimum:

MinInput = min(min(I)); % This is the cause of your problem.
MaxInput = max(max(I));

Use this instead:

MinInput = min(I(:));% Global min no matter how many dims!
MaxInput = max(I(:));

(What you would have had to do is call MIN a third time...)

Answer 2

[Walter Roberson]

You are assuming that imread() is returning a 3D array (you index it that way), but you are only applying two levels of max() and min() so you are going to be getting vector results for max() and min().

I suggest you recode

MinInput = min(I(:));
MaxInput = max(I(:));