To write multiple integral in latex, intuitive way is to use \int several times like \begin{equation} \int\int_{S} f(x,y)dxdy \end{equation} This code provides awful spacing between neighboring integral symbols. Alternative way is to use \…

Compute an integral image using MatLab. img = im2double(imread('test.bmp')); IntegralImage = cumsum( cumsum(img,1),2); Inside cumsum works along y direction while outside cumsum does along x direction.