Assuming that the pixel is interested I (u, v) = p0 and I ' (u, v) is the average filter through pictures and then another 8 surrounding pixels pixels is p1, ..., p2, p8 will.
Assume that the pixel of interest is I (u, v) = p0 and I '(u, v) is the average filter image and the pixels around the other eight pixels p1, p2, ..., p8 will.
Assuming that the pixels that interest is I (,) and u v = P0 I "(U V), an image through the average filter. The pixels around a 8 pixels. ,,, P1 P2... P8 will.