把一幅图像加上高斯噪声，再分别用均值和中值滤波的方法去除噪声。matlab仿真出的图像为四个：第一个为原图片，第二个为加高斯噪声后的图片，第三个为均值滤波后的图片，第四个为中值滤波后的图片。-Put an image plus Gaussian noise, then were mean and median filtering to remove noise. matlab simulation of the image into four: the first one is the orig