<span style="font-size:18px;color:#000099;">clear;sourcePic=rgb2gray(imread('lena.jpg'));%读取原图像grayPic=mat2gray(sourcePic);%转换成灰度图像subplot(121);imshow(grayPic);title('原图');[m,n]=size(grayPic);newGrayPic=grayPic;%为保留图像的边缘一个像素LaplacianNum=0;%经Laplacian算子计算得到的每个像素的值LaplacianThreshold=0.21;%设定阈值for j=2:m-1 %进行边界提取for k=2:n-1LaplacianNum=abs(4*grayPic(j,k)-grayPic(j-1,k)-grayPic(j+1,k)-grayPic(j,k+1)-grayPic(j,k-1));%newGrayPic(j,k)=LaplacianNum;if(LaplacianNum > LaplacianThreshold)newGrayPic(j,k)=255;elsenewGrayPic(j,k)=0;endendendsubplot(122),imshow(newGrayPic);title('Laplacian算子的处理结果')</span>