matlab中图像处理的基本函数（1）

I1= imread('E:\training1\s.jpg');
I1是一个m*n*t的矩阵

I2=rgb2gray(I1);

thresh = graythresh(I2);     %自动确定二值化阈值
I3 = im2bw(I2,thresh);
其中thresh是可变的二值化阈值，这里的值为0.5255

I4=medfilt2(I2,[3,3]); %中值滤波

grayPic=mat2gray(I2); %实现图像矩阵的归一化操作
[m,n]=size(grayPic);
newGrayPic=grayPic;%为保留图像的边缘一个像素
robertsNum=0; %经roberts算子计算得到的每个像素的值
robertThreshold=0.2; %设定阈值
for j=1:m-1 %进行边界提取
for k=1:n-1
robertsNum = abs(grayPic(j,k)-grayPic(j+1,k+1)) + abs(grayPic(j+1,k)-grayPic(j,k+1));
if(robertsNum > robertThreshold)
newGrayPic(j,k)=255;
else
newGrayPic(j,k)=0;
end
end
end