摄像机成像模型是决定视觉测量精度的关键因素之一。随着视觉测量精度的要求越来越高，提高摄像机模型和标定的精度是解决该问题的主要手段。将一种新的有理函数式镜头畸变修正模型引入到摄像机的成像建模中，以更好地修正镜头畸变引起的误差，从而提高摄像机成像模型的精度；并提出一种两步求解以及分步迭代优化的方法精确求解成像模型中各参数，以解决有理函数式畸变模型参数无法直接求解的问题。实验结果表明，基于新畸变修正模型的摄像机成像模型比常规畸变修正模型的标定精度有显著的提高，并且新模型对大误差的控制更有效，从而可整体提高视觉测量的精度。

Camera imaging model is a key factor to determine the accuracy of vision measurement. With the increasingly demand for accuracy in visual measurement, improvement of the accuracy of camera model and calibration are primary means to solve the accuracy problem. A new model of the rational function lens distortion model is introduced into the camera imaging model, which can better correct the errors caused by lens distortion, and thereby, it can improve the accuracy of the camera imaging model. Moreover, a two-step and step-iterative optimization method is proposed to precisely obtain the parameters of camera imaging model and to solve the problem that the parameters of the rational function lens distortion model cannot be solved directly. The experimental results demonstrate that the accuracy of the camera imaging model with the new distortion correction model is better than the conventional model and the new model can also effectively reduce the large errors. Therefore, the new camera imaging model and calibration method can improve the accuracy of visual measurement comprehensively.