CCD摄像机标定的研究

Research on CCD camera calibration

在计算机视觉中,二维计算机坐标和三维物体空间坐标的关系可通过摄像机模型来建立。模型中的参数包括:摄像机几何、光学特性参数(内参数)及摄像机空间位置参数(外参数)。摄像机的标定就是要确定这些参数。本文分析了三维空间点投影在像平面的像点产生畸变的原因:在大视场摄像机镜头各向同性,而且物像空间媒质均匀的情况下,像素单位元面积产生的变化引起像点畸变,并在实际图像坐标到计算机图像(帧存)坐标标定过程中推导出CCD传感器单元X方向的比例系数Nx的表达式,并进行了实验测量分析,取得的结果对提高标定精度具有意义。

With computer visual technology, the relationship between 2-dimensional computer coordinate and 3-dimensional space coordinate system is built by camera model. Model parameters include camera geometrical and optical （inside parameters） and space camera positional parameters （outer parameters）. Camera calibration aims at getting these. The paper produces that the essence of distortion produced by image spot on the image plane projected from 3-dimensional space dot is due to distortion of pixel unit area. And deduce expression of scale coefficient along axe x of CCD sensor unit during calibration from physical image coordinate system to computer frame system.