The Study Of 3D Point Cloud Hole Filling Method Based On Ridge And Valley Line

With the development of three-dimensional information technology,point cloud hole filling technology has become an important research topic.But so far,it is still not satisfactory to fill the complex holes with sharp features or various surface types.In this paper,combining with the salient features of the point cloud-ridge and valley characteristics,we present hole filling methods based on the ridge and valley.The main work focuses on the following aspects:(1)For the complexity of hole filling,we give a repair method of the ridge and valley lines based on human-computer interaction.Firstly,this method obtains the boundary points according to the method of quadrant,and obtains the feature points by using the curvature characteristics of the points.Then,we group these points,connect these points to form the boundary lines and the ridge and valley lines with the minimum spanning tree method.Based on human-computer interaction,we select and pair the ridge and valley lines near the boundary lines of the hole,and use the curve fitting method to integrated the ridge and valley lines to restore the ridge and valley lines in the hole.(2)For the sharp features preserving problems of the small hole filling,we give a overall method of point cloud hole filing based on the hole surface fitting under the control of ridge and valley lines.Firstly,fit the curve by pairing the hole boundary points to generate a series of curves.Then,make interpolation of these fitting curves to generate a sequence of control points under the limit of the ridge and valley lines which represent the structure information of hole.Finally,the NURBS surface fitting is used to fit the hole.(3)For the contour shape features preserving problems of the big hole filling,we design and implement a hole-dividing method of point cloud hole by using the ridge and valley lines.Firstly,divide the hole based on the repaired ridge and valley lines.Then,for each small hole,calculate the control points of NURBS surface fitting under the limit of the boundary lines and the ridge and valley lines.Finally,use the NURBS surface to fit each small hole.Then we complete the hole filling.The method of this paper not only provides effective support for the inevitable hole filling in point cloud measurement,but also provides a good way for the robustness of various methods based on point cloud in the field of observation point cloud.