Method for correcting detected distance values

Abstract

A method of the invention corrects a detection error, caused by an assembly error, in a distance or a distance-related index detected from an image captured in the visual field of an image detection module including an optical device and a pair of image sensing devices, each including a plurality of image sensors. In the method, the visual field is divided into windows disposed in a two-dimensional matrix format in order to detect the distance or a parallax for a pair of images in each window; the characteristics of an error is expressed in a detected value caused by an angle error in the assembly of the image detection module, as a quadratic polynomial for two angle variables indicating the position of the window within the visual field; parallax for a plurality of windows is detected after a test sample image has been provided to the module; the coefficient value for each term in the polynomial is determined based on the results of the detection, and these values are stored in a storage device; and, when using the image detection module to detect actual distances, the detected value for each window is corrected by adding to it the value of the polynomial to which the stored values of the coefficients and the values of the variables indicating the position of the window are applied.