Provided is an image processing device capable of performing appropriate noise reduction without causing blurring of edges and details of the image. The image processing device: specifies, on a normal distribution representing a noise model of the image, a reference range having a value of a target pixel as a median; computes, with respect to a local region that is an image region containing the target pixel, the number of pixels having a value falling within a first sub-range of the reference range and the number of pixels having a value falling within a second sub-range of the reference range, the first sub-range corresponding to larger values than the median and the second sub-range corresponding to smaller values than the median; corrects one of the first sub-range and the second sub-range so that one of the sub-ranges in which a fewer number of pixels are distributed than in the other sub-range is narrower relative to the other sub-range; determines a selection range that is composed of the one of the first sub-range and the second sub-range as corrected and the other one of the first sub-range and the second sub-range as is; and performs noise reduction on an image region subjected to noise reduction and at least containing the local region by using values falling within the selection range from among the values of the respective pixels contained in the target region.