现场测量摄影中透视关系的修正研究

Calibration of Perspective Relation in Crime Scenes Photogrammetry

为了准确获得现场勘查中物品之间的相互位置关系,提出了一种利用透视关系修正测量摄影结果的新方法。通过拍摄不同焦距的照片并利用数理统计理论分析实验数据,得到透视变形关系公式,通过比较实际放大倍率和利用公式得到的放大倍率之间的差值,量化畸变矫正的系数从而对计算结果进行修正。实验结果表明使用本方法进行修正后,测量误差由0.25%下降到0.1%。该方法可以运用在实际的现场勘查中来缩小误差,具有实用价值。

A new method of calibrating the photogrammetry is proposed by applying perspective relation to get the accurate position of objects at crime scenes. The perspective distortion formula can be got by taking different focus images and using the theory of mathematical statistics analysis of the experimental data. The calibrated coefficient of distortion was quantified by comparing the difference of magnification between the actual and the formula results. The calibration error of photogrammetry drops from 0.25% to 0.1% after using the proposed method. So this method can be applied in the criminal scene investigation to reduce the error, which also has practical value.