Camera calibration from a single image based on coupled line cameras and rectangle constraint

Given a single image of a scene rectangle of an unknown aspect ratio and size, we present a method to reconstruct the projective structure and to find camera parameters including focal length, position, and orientation. First, we solve the special case when the center of a scene rectangle is projected to the image center. We formulate this problem with coupled line cameras and present the analytic solution for it. Then, by prefixing a simple preprocessing step, we solve the general case without the centering constraint. We also provides a determinant to tell if an image quadrilateral is a projection of a rectangle. We demonstrate the performance of the proposed method with synthetic and real data.