中文摘要：

变焦镜头的标定和跟踪技术已广泛应用于虚拟演播室，体育视频转播等领域。由于在长焦范围，普遍采用的针孔模型已不再适用．导致长焦镜头的标定和跟踪难以达到较高的精度。从分析变焦镜头内部结构出发，对变焦时透镜组之间的相互运动与摄像机外参之间的关系进行详细研究，提出用补偿矩阵来补偿变焦过程中产生的摄像机外参的偏移。该方法在不改变原有摄像机标定方法的基础上，解决了变焦镜头跟踪问题。实验表明：利用补偿矩阵的方法，当镜头焦距达到80mm时，仍然能够将像素误差控制在3．有效地提高了跟踪精度。

英文摘要：

Camera calibration and zoom tracking play an important role in camera tracking, which is widely used in virtual studio, sports broadcast and other concern fields. However, when the focal length becomes longer, the widely used pin-hole model, which can only work well on short-focus lens, is not accurate enough if used in camera calibration and zoom tracking. Accordingly, in order to solve the problem of telephoto lens calibration, a new method was presented by analyzing the intrinsic structure of zoom lens and the relationship between the movement of lens group and the bias of camera pose. A compensation matrix was utilized to compensate the bias of extrinsic parameters of camera when the focal length was changed. The method improved the accuracy of zoom tracking by compensating the bias of camera pose, without changing the camera calibration itself. The experimental results show that the pixel errors are less than 3 pixels when the focal length reaches 80 mm.