How to add cell array elements iteratively?

I have a cell array of 36 elements and each element is a image of 25x256 unit8 dimension. I want to add all these elements iteratively. I am able to do so by adding one by one but unable to add them in a loop. I am getting the error shown in below picture.

Answer 1

[Geoff Hayes]

Hassan - first, please rename the sum variable since there is a built-in MATLAB function of the same name. If you want to add all of these matrices together (assuming that all are 25x256) then just do

compositeImage = im{1};
for k=2:length(im)
    compositeImage = compositeImage + im{k};
end

In your code, you are getting an error because you should be referencing im instead of sum when adding the kth image...since it is im that is the cell array.

[Hassan Ashraf]

Thank you Geoff Hayes.