An image processing apparatus which includes: an imaging device; a reference luminance property storage device that stores a predetermined reference luminance property; a luminance property calculating device that calculates a luminance property of the imaging device from an image obtained by the imaging device; a comparing device that compares the reference luminance property and the luminance property; a displacement determining device that determines whether or not the luminance property has relative displacement with respect to the reference luminance property based on a comparison result of the comparing device; and a luminance property correcting device that corrects the luminance property, wherein, when the luminance property is determined by the displacement determining device to have relative displacement with respect to the reference luminance property, the luminance property correcting device corrects the luminance property so as to become equivalent to the reference luminance property.