说明：  放大显示matlab输出图像局部区域，放大区域可以随意在原图像拖动，相应的放大区域会显示出来，同时显示放大区域和源图像。
(Zoom to display the matlab output image local area magnified area can freely drag in the original image corresponding to enlarge the area will be displayed, at the same time to enlarge the area and the source image.)