摄影测量中CCD相机精度对比方法研究

Comparison method for CCD camera accuracy in photography measurement

数字摄影测量在逆向工程和三维检测方面具有广泛应用。对摄影测量中CCD相机的测量精度进行探讨,提出一种基于数理统计的计算方法。通过相机拍摄多组照片,在XJTUDP软件下计算相同条件的编码点或非编码点之间的距离,得出其平均值,将测得的每组单个数值减去平均值,可获得每次测量的个体误差。求个体误差与平均值的比值的绝对值,可得出单组数组的测量精度。对测量精度求平均值,得出标准精度的概念。将标准精度作为衡量CCD相机测量精度的指标。结合试验数据,应用本方法对Cannon400D定焦相机和变焦相机进行较详细的分析,为定焦和变焦相机的选取提供依据。

Digital photography measurement is widely used in the fields of reverse engineering and 3D inspection. CCD camera measurement accuracy in the photography measurement is discussed. A calculation method based on the mathematical statistics is put forward. The distance of coded points or uncoded points was calculated with several groups of photographs taken by a camera with software XJTUDP, and then their average value was acquired. The individual error of each measurement was obtained by subtraction of the average value from the measured individual value of each group. The measuring accuracy of every group and the concept of standard accuracy were acquired by deriving the absolute value of ratio between the individual error and average value. The standard accuracy can be taken as the criteria for judging the accuracy of CCD cameras. The Cannon400D fixed-focus camera and zoom camera were analyzed in combination with the method and experiment data. The scientific basis for selection of zoom cameras and fixed-focus camera was provided.