To specify an object appropriate for distance calculation from within an image and appropriately calculate a distance from the object to a camera.

A computer is caused to execute processing for: obtaining an image from a camera; extracting a feature point satisfying an extraction condition specifying a feature point on a road surface from the image; and calculating a distance in the real space from the extracted feature point to the camera using an angle in the real space of the feature point calculated based on the position of the feature point in the image with respect to the camera and installation information including a depression angle of the camera and a distance from the road surface.