Ranging apparatus and ranging method

A ranging apparatus comprising:

• a first light source that irradiates a subject with a first illumination light;
• a second light source that irradiates the subject with a second illumination light;
• a distance sensor that detects a light from the subject and generates a distance image;
• a light source control unit that switches between a normal pattern of lighting the first light source and the second light source, a first evaluation pattern of lighting the first light source, and a second evaluation pattern of lighting the second light source;
• a correlator that calculates, for each of a plurality of evaluation regions set in the distance image, a correlation value between a first evaluation distance image generated at a time of irradiation with the first evaluation pattern and a second evaluation distance image generated at a time of irradiation with the second evaluation pattern;
• and
• a smoothing processing unit that generates a corrected distance image by applying a smoothing process of an intensity determined by the correlation value to a normal distance image generated at a time of irradiation with the normal pattern.