How would I vectorise this code

tempSum = 0;

for m = topLeft(2) : topLeft(2) + widthhight(2) -8
    for n = topLeft(1) :  topLeft(1) + widthhight(1) -8
        for x = 0 : 8
            for y = 0 : 8
                tempSum = tempSum + double(double(i(n+y,m+x)) * kernel(y+1,x+1));
            end
        end
        
        result(n + 4,m + 4) = tempSum/81;
        tempSum=0;
    end
end

[Walter Roberson]

conv2() some subset of i with kernel as being the thing to convolve with. Use the 'valid' option, I suspect.

[Josh Webb]

Thank you, a lot faster now. I knew about conv2 but didn't know about the "valid" argument