Function imageproc::integralimage::sum_image_pixels

pub fn sum_image_pixels(
    integral_image: &Image<Luma<u32>>, 
    left: u32, 
    top: u32, 
    right: u32, 
    bottom: u32
) -> u32

Sums the pixels in positions [left, right] * [top, bottom] in F, where integral_image is the integral image of F.