US Patent 7659921 Distance measurement apparatus, distance measurement method, and distance measurement program

Captured images taken by cameras are corrected in accordance with characteristics of the lens system of the cameras to produce corrected images. A pixel position detector then obtains the pixel position of the object on each corrected image. With reference to calibration tables, each of which correlates one of a pixel position on a coordinate system of each corrected image and information having a predetermined relation to the pixel position with information specifying a direction and a position of incident light traveling to the pixel position, the direction and the position of the incident light are obtained. Based on the direction and the position of the incident light, the distance to the object OB can be calculated.