A method for reducing noise and an apparatus therefor are provided to prevent generation of outlier by differentiating weighted value of an order statistic filter kernel and two noise filter kernels based on outlier probability. An apparatus for reducing noise comprises the followings: a noise level estimating unit(610) producing a noise level of an input image; a binary image generating unit(620) producing a binary image; a binary image correcting unit(630) amending the binary image; an edge effect diminution unit(640) reducing boundary of binary data in the binary image; and an area activity base weighted value controlling unit adding the weighted value to the noise filter kernel of small size and big size according to the activity of an area.
