A method for reducing image noise includes calculating a first pixel amount of pixels that are similar to each other in a first number neighbor of a center pixel in a motion window, determining whether the first pixel amount of pixels that are similar to each other in the first number neighbor is greater than a first predetermined value, and using a mean of those pixels of the first pixel amount of pixels that are similar to each other in the first number neighbor to restore the center pixel of the motion window if the first pixel amount of pixels is greater than the first predetermined value. The method includes determining whether a second pixel amount of pixels that are similar to the center pixel is greater than a second predetermined value if the first pixel amount of pixels is not greater than the first predetermined value.