摄影测量的射影失真自修正算法

摘要

针对传统的摄影测量中由于相机倾斜而产生的射影失真，提出了一种具有射影失真自修正功能的弹丸立靶坐标摄影测量法。分析了射影失真产生的原因及其对测量精度的影响。通过对靶面上任意点分析其成像关系，推导出了任意点的物距求解公式，建立了弹孔在图像上的像素坐标与在靶面上的立靶坐标之间的映射模型。通过对靶面上4个控制点的提取和计算，求解出映射模型中的状态常量，从而克服了由射影倾斜所造成图像失真引入的测量误差，实现了对立靶坐标的绝对测量。实弹测试试验结果表明，该方法能够准确测量弹丸的立靶坐标，提高了射击密集度参数判读的准确性和一致性，能够对相关自动化检测仪器进行校验。%Proj ective distortion is often caused by the tilted camera in the traditional photogrammetry. To deal with this problem,proj ective distortion self-corrected photogrammetry is proposed to measure the proj ectile ’ coordinates.The causes of proj ective distortion and its impact on the measurement accuracy are analyzed.Based on the imaging model of any random point on the target,the formula for solving the obj ect distance is deduced.Then the correspondence between the proj ectiles coordinates on the image and their coordinates on the target is established.Through extraction and calculation of 4 markers sited on the target,the constant in the correspondence is determined.The measurement error caused by proj ective distortion is eliminated,realizing the absolute measurement of proj ectile coordinate on the target.The test results show that the proj ectile coordinate on the target can be accurately measured by the new proposed method,which can improve,the accuracy and consistency of fire intensity measuring and can be used to check other related automatic measuring equipments.