1. An image processing apparatus comprising: a first determination unit configured to determine whether or not a first area consisting of a plurality of pixels including a pixel of interest is an area in a uniform color for the pixel of interest in input image data; a second determination unit configured to determine whether or not a second area, different from the first area, consisting of a plurality of pixels including the pixel of interest is an area in a uniform color; a setting unit configured to set a reference area consisting of the pixel of interest and adjacent pixels of the pixel of interest for the pixel of interest; and a first correction unit configured to correct the pixel value of the pixel of interest to a value for which noise has been reduced based on the pixel value of the pixel included in the reference area, wherein the setting unit sets: a predetermined area prepared in advance and consisting of a plurality of pixels as the reference area in a case where the first determination unit determines that the first area is an area in a uniform color; and an area consisting of a plurality of pixels in accordance with determination results by the second determination unit as the reference area in a case where the first determination unit determines that the first area is not an area in a uniform color.