应用半球图像构建的立木高度测算方法  

Measuring Standing Wood Height with Hemispherical Image

作　　者：宋佳音[1] 张晓鹏 宋文龙[2] 池志祥 杨柳松[2] 孙海龙[2] 李秋石 Song Jiayin;Zhang Xiaopeng;Song Wenlong;Chi Zhixiang;Yang Liusong;Sun Hailong;Li Qiushi(Northeast Forestry University,Harbin 150040,P.R.China)

机构地区：[1]东北林业大学机电工程学院,哈尔滨150040 [2]东北林业大学,哈尔滨150040

出　　处：《东北林业大学学报》2020年第6期61-65,共5页Journal of Northeast Forestry University

基　　金：黑龙江省青年科学基金项目(QC2016080);中央高校基本科研业务费专项基金项目(2572017CB13)。

摘　　要：结合鱼眼相机标定技术、近景摄影测量技术、图像处理技术,提出了应用半球图像测算立木高度的测量方法。利用配有鱼眼镜头的iPhone7苹果手机采集半球图像,图像尺寸为3024×3024像素时,图像光学中心点坐标用图像中心点坐标代替,畸变系数分别取kx=18.141、ky=17.936;依据鱼眼镜头的标定、校正原理建立测算树高的数学模型,给出模型参数标定步骤;通过实地测量与计算,分析半球图像立木高度测算方法与传统的超声波测高方法的差异。结果表明:半球图像立木高度测算方法,最高相对误差为3.35%,能够满足国家森林资源二类调查中对树高测量精度的要求。与超声波测距仪相比,半球图像立木高度测算方法——精度更高、测量结果更稳定;测量范围广、单幅采集立木信息量大,能在一幅半球图像中实现一排树的树高测算,有效降低测量工作量;成本低、设备便携、操作简单,单人即可完成测量。Combining with the fish-eye camera calibration technology,close-range photogrammetry technology and image processing technology,we proposed a method for measuring the standing wood height using hemispherical image.The iPhone7 with fish-eye lens is used to collect the hemispherical image whose size is 3024×3024 pixel,the image optical center coordinates are replaced by the image center coordinates,and the distortion coefficients are kx=18.141 and ky=17.936.According to the principle of fish-eye lens calibration and correction,the mathematical model of measuring height for standing wood is established,and the steps of model parameter calibration are given.The difference between the method for measuring the height of standing wood based on hemispherical image and the traditional ultrasonic method of measuring tree height has been analyzed after field measurement and calculation.The results show that the maximum relative error of the method is 3.35%,which can meet the requirement of height measurement accuracy in national forest resources survey.Compared with ultrasonic rangefinder,the method for measuring the height of standing wood based on hemispherical image is more accurate and more stable,the measurement range is wider,the information of single image is more,and a row of trees height can be measured in a hemispherical image,which can effectively reduce the measurement workload;The advantages of this utility method are low cost,portable equipment,simple operation and easy application by one person.

关 键 词：立木高度 测算方法 半球图像 鱼眼镜头 

分 类 号：S758.1[农业科学—森林经理学]