一种平滑程度可控的等高线平滑方法  

A Contour Smoothing Method with Controllable Smoothness

作　　者：邱伟 郭丙轩[1] 肖雄武 QIU Wei;GUO Bingxuan;XIAO Xiongwu(State Key Laboratory of Information Engineering in Surveying,Mapping and Remote Sensing,Wuhan University,Wuhan 430079,China)

机构地区：[1]武汉大学测绘遥感信息工程国家重点实验室,湖北武汉430079

出　　处：《测绘与空间地理信息》2021年第7期90-94,共5页Geomatics & Spatial Information Technology

基　　金：国家自然科学基金重大研究计划重点支持项目(91638203);国家重点研发计划(2016YFB0502200,2018YFB0505401);国土资源部城市土地资源监测与仿真重点实验室开放基金资助课题(KF-2018-03-052)资助。

摘　　要：提出了一种能够通过具有实际意义的参数控制等高线平滑程度,通过等高线平滑可以控制等高线细节的表达程度的方法,能够完成不同尺度下等高线的简化;算法通过结合曲线平滑和迭代最大残差抑制方法,完成等高线平滑程度控制,此时全体高程点平面位移均低于给定平滑容差。首先通过自适应算法选取最大平滑因子,对全体高程点进行平滑处理,选择点位位移最大高程点进行局部处理,以一定倍率逐渐减小平滑因子,使得该点点位位移低于给定平滑容差;不断重复该过程,直到全体高程点点位位移均低于给定平滑容差,从而完成等高线平滑程度的控制。经实验验证,等高线平滑后曲线曲率更小,曲率变化更加均匀,且等高线精度能够通过参数进行控制。A method is provided to control the smoothness of contours through parameters.Contour smoothing can control the expression of contour details and can represent contour in a larger scale.The algorithm completes the contour smoothing degree control by combining curve smoothing and iterative maximum residuals suppression method.At this time,the displacement of all elevation points is lower than the given smoothing tolerance.Firstly,the maximum smoothing factor is selected by adaptive algorithm,and the whole elevation point is smoothed,and the maximum elevation point of point displacement is processed locally.The smoothing factor is continuously reduced at a certain rate,so that the point displacement is lower than the given smoothing tolerance.The process is repeated iteratively until all elevation points are located.The moving average is lower than the given smooth tolerance,so as to control the smoothness of contour lines.The experimental results show that the curvature of the contour is smaller and the curvature changes more uniformly after smoothing,and the accuracy of the contour can be controlled by parameters.

关 键 词：等高线平滑 平滑程度控制 迭代最大残差抑制方法 最小二乘平差 三次B样条插值 

分 类 号：P216[天文地球—测绘科学与技术]