像锐化的目的是加强图像中景物的边缘和轮廓。锐化的作用是要使灰度反差增强。因为边缘和轮廓都位于灰度突变的地方。所以锐化算法的实现是基于微分(差分)作用。-Like sharpening is to enhance the edges of the image and profile features. The role is to make the grayscale sharpening contrast enhancement. Because the gray edges and contours are located where mutations. So sharpening algorithm implementation is based on the differential (differential) effect.