图像预处理(Evision)

Convolution 　　　　 //采用线性过滤
Linear combination of neighboring pixels using a convolution kernel
−Pre-defined filters for
Edge detection　　　　　　　　　　　　　　　　　　//功能
Laplacian, Gradient, Prewitt, Sobel, Roberts　　　　//对应方法
Sharpening with several high-pass filters
Smoothing
Several low-pass including Gaussian filter and uniform filters