pub fn integral_squared_image<P, T>(image: &Image<P>) -> Image<ChannelMap<P, T>>
where
    P: Pixel<Subpixel = u8> + WithChannel<T>,
    T: From<u8> + Primitive + AddAssign,
{
    integral_image_impl(image, true)
}
Computes the 2d running sum of the squares of the intensities in an image. Channels are summed
independently.

See the [`integral_image()`] documentation for more information on integral images.

# Examples
```
# extern crate image;
# #[macro_use]
# extern crate imageproc;
# fn main() {
use imageproc::integral_image::{integral_squared_image, sum_image_pixels};

let image = gray_image!(
1, 2, 3;
4, 5, 6);

let integral = gray_image!(type: u32,
0,  0,  0,  0;
0,  1,  5, 14;
0, 17, 46, 91);

assert_pixels_eq!(integral_squared_image::<_, u32>(&image), integral);

// Compute the sum of the squares of all pixels in the right two columns
assert_eq!(sum_image_pixels(&integral, 1, 0, 2, 1)[0], 4 + 9 + 25 + 36);

// Compute the sum of the squares of all pixels in the top row
assert_eq!(sum_image_pixels(&integral, 0, 0, 2, 0)[0], 1 + 4 + 9);
# }
```
src/integral_image.rs