Calibration and three-dimensional reconstruction using epipolar constraints on a structured light computer vision system

A new structured light computer vision system was developed to determine 3 dimensional geometry information of objects. The system was composed of a dot matrix pattern laser projector, and two cameras (labeled as A and B). Here, the camera A is called main camera. The cameras (B) functions as a checking device to determine the correct image matching between the main image and the projector, so it is called checking camera. There are three contributions in this dissertation and they are as follows: First, a new camera calibration technique is provided, in which the image center, uncertainty scale factor, camera focal length, rotation matrix, and translation vector can be determined using at least seven noncoplanar calibration points; the orthogonality of rotation matrix can be satisfied not only theoretical but also numerically with actual calibration; all intrinsic and extrinsic parameters can be determined using the same set of data; no assumption is needed for the world coordinate system setup; and no nonlinear techniques are required. Second, a new linear approach for estimating the epipolar lines on the main camera (A), related to the projector, is developed. The existing methods can not guarantee that all image points on the same epipolar line on the main camera, related to the projector, have the same corresponding epipolar line on the projector. This is against the epipolar geometric constraints. The approach developed here can guarantee that all points on the same epipolar line on the main image, related to the projector, must have the same corresponding epipolar line on the projector. Third, two checking point equations are given to determine the correct image matching among the main image, the checking image, and the projector. The methods developed here, only require use of the epipolar lines on the projector, related to the main camera (A). Calibration of the projector is not required. A review of the state of the art is given in the first three chapters. All methods developed here were verified experimentally.