Research On 3D Scanning Data Processing Techniques

In recent years, with the rapid development of computer science and information technology, reverse engineering technology has been widely used in various fields. Various aspects of reverse engineering, such as surface information acquisition, date procession techniques, surface reconstruction are the current hotspot. The reverse engineering consists of data acquirement, data pre-processing and reconstruction. Data acquirement can obtain the coordinates of the discrete points by the fixed measuring equipment and methods. Data pre-processing includes transformation of data format, data splicing, data smoothing and data cracking. The process decides whether the following CAD model reconstruction process is convenient, and whether the reconstruction model meets the application need. The goal of surface reconstruction is to seek some mathematics description form, which satisfies the given precision, effectively describes the shape of physical surface, and carries on the analysis, the computation, the revision and the rendering of the surface itself in this foundation.This paper comes from project of "Precision engineering and industrial measurement Key Laboratory of the National Mapping Agency Fund". And it discusses of data processing and surface fitting techniques based on the real 3D laser scanning point cloud data. The paper's main tasks include the following components: First of all, computing cloud curvature and compressed 3D laser scanning data on Matlab software platform. And then complete surface modeling and surface reconstruction on Imageware software platform surface.(1)The paper presents a based on point cloud data's curvature compression algorithm, and use real raw tunnel's point cloud as handle objects, compresses on Matlab software platform, and visual display compressed data before and after the point cloud on software platform in Imageware, contrast compression.(2) It focuses on the commercial software Imageware's main modules and data processing features, which use to process point cloud data,(3)The paper detailed 3D laser scanning point cloud data's robust and wavelet threshold denoising algorithm, the regional focus of peak compression and compression algorithm, and the Bezier and NURBS surface fitting method.Experiments demonstrate that thesis based on the curvature of the point cloud data compression algorithm, the real point cloud compression can achieve 75% or even higher compression ratio. And visual display through Imageware show that the algorithm in access to higher compression than the same time, raw data is described in three-dimensional shapes better fidelity. It show that the 3D point cloud processing method in the paper have a certain significant for future.