boxFilter convolves the source image with the
 specified box kernel (a matrix of 1s). The result is a blurred version of
 the source image.
boxFilter(image, k_height = 5, k_width = 5)| image | An  | 
|---|---|
| k_height | The half-height in pixels of the kernel (default: 5). | 
| k_width | The half-width in pixels of the kernel (default: 5). | 
image An Image object.
Simon Garnier, garnier@njit.edu
# TODO