摘要
基于圆的摄像机标定有着无可比拟的优势.目前,虽有文献证明了圆在反射折射摄像机下的像是一条四次曲线,但由于存在遮挡,仅仅部分封闭曲线在像平面上是可见的,且通过其可见部分无法拟合圆像的方程,进而无法标定摄像机参数.因此,当摄像机位率为1且斜率为0时,作者提出了一种抛物反射折射圆像的拟合方法,为研究基于圆的摄像机标定算法奠定了基础.首先,推导出了抛物反射折射圆像需要满足的条件;其次,在这些条件基础上提出了一种抛物反射折射圆像的拟合方法;最后,利用拟合得到的抛物反射折射圆像和通过抛物镜面的投影轮廓线估计得到的摄像机主点直接计算出摄像机焦距,以此评价文中拟合方法的性能.大量的模拟实验和真实实验均验证了文中拟合方法的有效性.
Camera calibration from circles has great advantages. Although it is proved that the image of a circle under catadioptric camera is a quartic curve, only part of the quartic curve is visible on the image plane due to the partial occlusion. Consequently catadioptric circle image cannot be estimated from the visible part and camera parameters cannot be calibrated. In this paper, we propose a fitting method of paracatadioptric circle image for the case that aspect ratio is 1 and skew is O, and establish the foundation for calibration methods based on circles. First, we derive some conditions, which must be satisfied by the paracatadioptric circle image. Second, based on these conditions, we present a fitting method of the paracatadioptric circle image. Finally, we evaluate the performance of our fitting method using the focal length which is computed from paracatadioptric circle image and the principal point that is estimated from the projected contour of parabolic mirror. Experimental results on both simulated and real image data have demonstrated the effectiveness of our method.
出处
《计算机学报》
EI
CSCD
北大核心
2012年第10期2063-2071,共9页
Chinese Journal of Computers
基金
国家"八六三"高技术研究发展计划项目基金(2010AA122200)资助
