The Decreasing of 3D Position Errors in the System of Two Cameras by Means of the Interpolation Method

Abstract

In this paper the original method of 3D position errors decreasing in the system of two cameras is proposed. The analysis of accuracy of determining the 3D coordinates of points on the plane template in the shape of rectangle is presented. The points lie at the corners of squares with side of 22 mm. Images of these points were obtained using Edimax IC-7100P cameras from two different points of view and analyzed. Position and orientation coordinates of cameras relatively to the reference system were calculated. Coordinates of points on the ideal image (without optical distortions) were determined. After reading from the image real coordinates, optical distortion model coefficients of the camera were calculated. After that, errors caused by optical distortion were determined. Coordinates read from the image were corrected and coordinates of observed points in the reference system were calculated. Next to decreasing computed 3D position errors the interpolation method was proposed. In this method the interpolation of the real coordinates of image points was used. The calculated coordinates were compared to them real values and them maximal differences were determined. Finally, the maximal position errors caused by finite dimensions of pixels were computed.