对三维图像进行求导的一个程序，利用高斯卷积后对图像求导相当于对高斯函数求导的性质。是用itk库写的一个通用模板类，里面还有例子。-Computation of local image derivatives is an important operation in many image processing tasks that involve feature detection and extraction, such as edges, corners or more complicat