An image processing apparatus includes: an evaluation value calculation unit configured to calculate a contrast evaluation value of each of first image data and second image data in which an object is imaged in a state in which auxiliary light is emitted to the object included in a first image corresponding to the first image data; a determination unit configured to determine that fog or haze is occurring at a time the contrast evaluation value of the first image data, which has been calculated by the evaluation value calculation unit, is equal to or greater than the contrast evaluation value of the second image data; and an image processing unit configured to perform image processing to the first image data or the second image data based on a determination result of the determination unit.