1. A lens dirtiness detection apparatus configured to detect a lens dirtiness of a camera, comprising: a control unit; and a memory coupled to the control unit, wherein the memory stores therein pixel value data of an image captured by the camera, and wherein the control unit is configured to: calculate image frequency power based on pixel values of a first region of the image; determine presence or absence of a lens dirtiness of the camera based on the image frequency power of the first region; and output the determination result on presence or absence of a lens dirtiness.