1. A noise reduction method, comprising: calculating a noise level of an input image; decomposing the input image into pixels of different color channels; determining an edge type of an edge of a central pixel; controlling a removing of noise from the central pixel, within a window in the input image of a predetermined size including respective pixels of the different color channels, using a weight determined with respect to the edge type of the central pixel, based on a difference between signal intensities of the central pixel of a respective color channel and a plurality of adjacent pixels of the respective color channel within the window and the calculated noise level excluding pixels within the window of a color channel different from the respective color channel; and determining whether impulse noise is contained in the central pixel, using plural threshold values, wherein when the impulse noise is determined to be contained in the central pixel, outputting a mean of weighted sums comprising outputting a mean of signal intensities of the plurality of adjacent pixels as a final signal intensity of the central pixel, wherein the outputting of the mean of the weighted sums comprises determining whether the impulse noise is contained in the central pixel using a rank-ordered absolute differences statistic (ROAD) calculated for the window.