/**
 \defgroup ITKImageGradient Module ITKImageGradient 
 This module contains filters that compute differential
operations in images. In particular, image gradients, gradient magnitude and
difference of Gaussians. 
 \par Dependencies:
 \li \ref ITKImageAdaptors 
 \li \ref ITKImageIntensity 
 \li \ref ITKSmoothing 
 \dot 
 graph "ITKImageGradient" { 
 "ITKImageGradient" -- "ITKImageAdaptors"; 
 "ITKImageGradient" -- "ITKImageIntensity"; 
 "ITKImageGradient" -- "ITKSmoothing"; 
 } 
 \enddot 
 */