subplot(2,2,1); imshow(input); title('原始图像'); water=imread('water.bmp'); subplot(2,2,2); imshow(water); title('水印'); input=double(input); water=double(water); inputr=input(:,:,1); waterr=water(:,:,1); inputg=input(:,:,2); waterg=water(:,:,2); inputb=double(input(:,:,3)); waterb=double(water