系统标定中的透视投影模型

Perspective Projection Model in System Calibration Process

以相机的透视投影模型为基础,根据椭圆拟合与投影变换,建立使用特定靶标计算两相机相对位置的标定模型。分析在不同坐标系下物点与像点的坐标转换关系,分别通过椭圆拟合模型和精确模型,提出求解空间圆的圆心在像平面上的像坐标的算法,并对精度和稳定性进行检验与分析。分析结果表明,椭圆拟合模型求解较简单、方便;基于透视投影变换规律的精度模型结果较精确,但需给出较多的相机外部参数。

According to the ellipse-simulation and projective transform,projective relation about center of certain circle is set up for calibrating the relative position of two cameras,based on the perspective projection model of camera.The transform between object point and image point under different reference frames is analyzed.Based on the ellipse-simulation model and precise model,the method to get the image point of a circle＇s center is put forward and its precision is checked.The analysis result shows that ellipse-simulation model is simple but convenient,and the precise model is more precise with more parameters from the camera.