matlab转灰度图片

%读取一张图片，并显示
original_picture=imread('C:\Users\Admin\Desktop\2004.png');
figure(1);
imshow(original_picture);
title('原始RGB图像')

%把图像转换成灰度图像
GrayPic=rgb2gray(original_picture);%把RGB图像转化成灰度图像
figure(2)
imshow(GrayPic);
title('RGB图像转化为灰度图像')
imwrite(GrayPic,'matlab灰度处理2004.png')