滤波一般用于消除图像中的随机噪声，故下面的程序先添加典型噪声，再进行各种滤波处理：均值滤波、中值滤波、最小值滤波、最大值滤波。 -Image filtering is generally used to eliminate the random noise, so the following procedure to add the typical noise, and then conduct various kinds of filter processing: mean filteri