单幅像片测量技术在伐根测量中的应用

摘要

Stump measurement can be used to speculate felling quantity,unlawful felling quantity or false felling quantity,confirm felling intensity and verify implementation of forest felling quota.Traditional stump measuring methods feature a heavy field workload and a low efficiency.As the development of close-range photogrammetry and performance improvement of digital imaging sensor,it is possible to measure dimensions of an object in a single photo.In this paper,a method for measuring stumps in a single photo shot with common digital cameras was proposed based on pin-hole imaging cross ratio invariability theory.Photo collection requirements and image processing flow of this method were introduced and verified by virtue of Sketchup software,experimental results and on-site ruler measuring results were compared.The results showed that this method could realize an accuracy of 94.36％.%伐根测量可推测过往采伐量、盗伐量或误伐量,还可确定采伐强度,核实森林采伐限额执行情况.传统伐根测量方法的外业工作量大、效率低,随着近景摄影测量技术的发展和数码成像传感器性能的提升,使得从单幅像片中测量物体尺寸成为可能.文章基于小孔成像交比不变性原理,提出了一种从普通数码相机任意姿态拍摄的单幅像片中测量伐根的方法.介绍了该方法的照片采集要求、图像处理流程、并借助Sketchup软件对该方法进行验证,将实验结果与实地直尺测量结果进行比较,结果表明该方法精度可达到94.36％.