Panoramic stereo reconstruction using non-SVP optics

Omni-directional sensors are useful in obtaining a 360° field of view with a single lens camera. Omni-directional stereo imaging systems were designed in our past research using a single camera and a mirror consisting of two concentric, radially symmetric lobes. If the central camera-mirror axis is vertical, a stereo image containing imagery from all azimuth directions from two viewpoints can be captured within one image. A vertically posed catadioptric optical system that employs a mirror with a radial profile other than parabolic or hyperbolic cannot maintain the straightness of any nonvertical lines. However, non-SVP (single view-point) mirror profiles are desirable for resolution distribution, sensor size and manufacturability. Since they lack a virtual perspective point, they pose new feature extraction challenges. A method for processing the imagery is introduced. Horizontal line segments are extracted using the panoramic Hough transform and vertical line segments are recognized as straight radial lines. These segments, and closed shapes they form are matched between the two lobe views to locate them in three-dimensions. Experimental results are presented.