摘要
合理选择摄像机模型是摄像机标定的首要任务,而传统的模型选择方法主要采用单一的重建精度指标来评判模型的合理性,存在明显的局限性.针对摄像机模型的比较和选择问题,分析和定义了模型的重建精度与泛化性能、模型估计的稳定性和标定参数的不确定性3个性能指标.重建精度与泛化性能指标不仅度量了模型对标定控制点范围内数据的重建误差大小,而且还反映了模型对于控制点范围之外数据的适应程度;稳定性指标描述了标定结果对于标定数据空间分布的依赖程度;不确定性指标则反映了标定结果的偶然性.这3个指标具有一定的互补性,且稳定性和不确定性指标无需进行重建,可以直接通过标定结果进行评判.最后以3个不同特点的摄像机及8种不同类型的畸变模型为例,通过实验验证了3个指标的合理性和可行性,为合理选择摄像机模型提供了一种有效途径.
The first step in camera calibration is to make a right choice of the camera model. Traditional ways of the model selection share an obvious limitation by mainly relying on a single evaluation measure, i.e. the reconstruction precision, to estimate a model＇s soundness. In this paper, aiming at the comparison and selection of different cameral models, we define and analyze three evaluation measures. The first one is the 3D reconstruction precision and generalization capability, measuring not only the reconstruction error for calibrated points but also the adaptability on points deviated from the calibrated ones; the second one is the stability, describing the extent to which the calibration result depends on the spatial distribution of the points; the third one is the uncertainty which reflects the randomness of one trial of calibration. These three meas-ures are mutually complementary, and the stability and uncertainty can be directly estimated through the calibration result without reconstruction. Finally, intensive experiments on three cameras with eight distor-tion models are conducted to verify the validity and feasibility of three proposed evaluation measures, which offers a helpful guidance for the selection of camera models.
出处
《计算机辅助设计与图形学学报》
EI
CSCD
北大核心
2015年第5期824-831,共8页
Journal of Computer-Aided Design & Computer Graphics
基金
国家自然科学基金(61373099)
太原科技大学博士启动基金(20122024)
