General Imaging Geometry for Central Catadioptric Cameras

Abstract. Catadioptric cameras are a popular type of omnidirectional imaging system. Their imaging and multi-view geometry has been extensively studied; epipolar geometry for instance, is geometrically speaking, well understood. However, the existence of a bilinear matching constraint and an associated fundamental matrix, has so far only been shown for the special case of para-catadioptric cameras (consisting of a paraboloidal mirror and an orthographic camera). The main goal of this work is to obtain such results for all central catadioptric cameras. Our main result is to show the existence of a general 15 × 15 fundamental matrix. This is based on and completed by a number of other results, e.g. the formulation of general catadioptric projection matrices and plane homographies. 1 Introduction and Previous Work The geometry of single and multiple images has been extensively studied in computer vision and photogrammetry [1]. The picture is rather complete for perspective cameras and many results have been obtained for other camera models too

Wide-angle visual feature matching for outdoor localization

Wide-angle images exhibit significant distortion for which existing scale-space detectors such as the scale-invariant feature transform (SIFT) are inappropriate. The required scale-space images for feature detection are correctly obtained through the convolution of the image, mapped to the sphere, with the spherical Gaussian. A new visual key-point detector, based on this principle, is developed and several computational approaches to the convolution are investigated in both the spatial and frequency domain. In particular, a close approximation is developed that has comparable computation time to conventional SIFT but with improved matching performance. Results are presented for monocular wide-angle outdoor image sequences obtained using fisheye and equiangular catadioptric cameras. We evaluate the overall matching performance (recall versus 1-precision) of these methods compared to conventional SIFT. We also demonstrate the use of the technique for variable frame-rate visual odometry and its application to place recognition

Textured mesh surface reconstruction of large buildings with multi-view stereo

10.1007/s00371-013-0827-zUser Modeling and User-Adapted Interaction296-8609-615VICO