均值滤波是典型的线性滤波算法，它是指在图像上对目标像素给一个模板，该模板包括了其周围的临近像素（以目标象素为中心的周围8个象素，构成一个滤波模板，即去掉目标象素本身）。再用模板中的全体像素的平均值来代替原来像素值。-Mean filter is a typical linear filtering algorithm, it refers to the image on the target pixel to a template, the template including its surrounding adjacent pixels (8 pixels around the target pixel to form a filter mask, that is, remove the target pixel itself). Then the average of all pixels in the template to replace the original pixel values​ ​ .