Unwrapping and stereo rectification for omnidirectional images  

作　　者：Jie LEI Xin DU Yun-fang ZHU Ji-lin LIU 

机构地区：[1]Institute of lnformation and Communication Engineering, Zhejiang University, Hangzhou 310027, China [2]Zhejiang Provincial Key Laboratory of lnformation Network Technology, Hangzhou 310027, China [3]College of Computer and lnformation Engineering, Zhejiang Gongshang University, Hangzhou 310027, China

出　　处：《Journal of Zhejiang University-Science A(Applied Physics & Engineering)》2009年第8期1125-1139,共15页浙江大学学报（英文版）A辑（应用物理与工程）

基　　金：supported by the National Natural Science Foundation of China (Nos.60502006,60534070 and 90820306);the Science and Technology Plan of Zhejiang Province,China (No.2007C21007)

摘　　要：Omnidirectional imaging sensors have been used in more and more applications when a very large field of view is required.In this paper,we investigate the unwrapping,epipolar geometry and stereo rectification issues for omnidirectional vision when the particular mirror model and the camera parameters are unknown in priori.First,the omnidirectional camera is calibrated under the Taylor model,and the parameters related to this model are obtained.In order to make the classical computer vision algorithms of conventional perspective cameras applicable,the ring omnidirectional image is unwrapped into two kinds of panoramas:cylinder and cuboid.Then the epipolar geometry of arbitrary camera configuration is analyzed and the essential matrix is deduced with its properties being indicated for ring images.After that,a simple stereo rectification method based on the essential matrix and the conformal mapping is proposed.Simulations and real data experimental results illustrate that our methods are effective for the omnidirectional camera under the constraint of a single view point.Omnidirectional imaging sensors have been used in more and more applications when a very large field of view is required. In this paper, we investigate the unwrapping, epipolar geometry and stereo rectification issues for omnidirectional vision when the particular mirror model and the camera parameters are unknown in priori. First, the omnidirectional camera is calibrated under the Taylor model, and the parameters related to this model are obtained. In order to make the classical computer vision algorithms of conventional perspective cameras applicable, the ring omnidirectional image is unwrapped into two kinds of panoramas： cylinder and cuboid. Then the epipolar geometry of arbitrary camera configuration is analyzed and the essential matrix is deduced with its properties being indicated for ring images. After that, a simple stereo rectification method based on the essential matrix and the conformal mapping is proposed. Simulations and real data experimental results illustrate that our methods are effective for the omnidirectional camera under the constraint of a single view point.

关 键 词：Single point of view CALIBRATION Catadioptric image unwrapping Omnidirectional stereo vision Epipolar geometry Essential matrix Conformal mapping 

分 类 号：TP391.41[自动化与计算机技术—计算机应用技术] TU998.12[自动化与计算机技术—计算机科学与技术]