An apparatus according to the present invention includes a detection unit configured to detect a noise based on pixel values of a neighboring pixel group having an interval of n pixel (s) (n is an integer of 1 or more) from a target pixel and a range of m pixel(s) (m is an integer of 1 or more) and a pixel value of the target pixel, and a replacement unit configured to replace the pixel value of the target pixel with an average value of the pixel values of the neighboring pixel group if the noise is detected.