图像加噪 matlab

I=imread('lena.bmp'); imshow(I) ; %叠加均值为0，方差为0.02的高斯噪声 J1=imnoise(I,'gaussian',0,0.02); %imnoise函数归一化原因，很小方差但效果很明显 figure,imshow(J1); %叠加密度为0.04的椒盐噪声 J2=imnoise(I,'salt & pepper',0.04); figure,imshow(J2); imwrite(J1,'lena_gaussian.bmp'); imwrite(J2,'lena_saltpepper.bmp');