Water droplet detection device, and three-dimensional object detection device using water droplet detection device

Abstract

A water droplet detection device has an image capturing unit and a water droplet detection unit. The image capturing unit has a photographic optical system that an area captures an image of a predetermined area. The water droplet detection unit sets an arbitrary attention point in the captured image, a plurality of first reference points inside an imaginary circle of a predetermined radius having the attention point as a center the imaginary circle, and a plurality of second reference points corresponding to the first reference points outside the imaginary circle. The water droplet detection unit detects edge information between the first reference points and second reference points, and assesses a circularity strength of the edge information to detect a water droplet attached to the photographic optical system. The water droplet detection device can be used with an image conversion unit to form a three-dimensional object detection device.