Reconstruction Of Three-dimensional Point Cloud Of Lingwu Long Jujube Basef On Line-Structured Light Measurement System

The purpose of this paper is to establish the 3D model of LingWu long jujube fruit by using HALCON language.Picking LingWu long jujube in outdoor environment,in fact the machine only able to identify the one side of the fruit,if can create tens of thousands of LingWu long jujube fruit three-dimensional model,can be used to identify the whole fruit surface,one side predicts the situation,for the final build LingWu long jujube stereoscopic image library has the certain reference value.The establishment of the model is also conducive to obtaining the three-dimensional size parameters of the fruit,judging the fruit maturity and the degree of skin damage from all directions,and can provide some theoretical basis and reference for the research and application of fruit grading detection,maturity detection and appearance quality detection.In this paper,the three-dimensional measurement system of linear structured light and turntable were used to obtain the three-dimensional information of the fruit surface of Lingwu Long Jujube from seven different perspectives,and seven depth images and grayscale images were obtained.Then,the depth image and the gray image are processed respectively.The former aims to obtain the point cloud model,while the latter aims to identify the marking points and locate the central point,and then obtain the transformation matrix between perspectives.Finally,the transformation matrix is used to splice seven point cloud models to complete the 3d point cloud reconstruction of LingWu long jujube.The main research contents of this paper are as follows:(1)Research on 3d measurement system of linear structured light.The system is mainly composed of two parts:hardware operating system and software operating system.This chapter studies the operation method,function function,main working principle of the system,theoretical knowledge of algorithm and relevant mathematical calculation model of the system.Research on depth image acquisition and processing of LingWu long jujube.(2)Study on identification and center location of mark points of LingWu long jujube.First of all,build a simple platform,LingWu long jujube fruit fixed on the platform.Secondly,adjust the camera and keep the best scanning distance,repeatedly operate the robotic arm to scan,to find the most appropriate scanning route.Then,complete setting of key parameters in 3DExplorer software.Then,manual rotation fixed on the platform of LingWu long jujube fruit,respectively from the Angle of seven different acquisition LingWu long jujube surface information,namely LingWu long jujube depth image,at last,through 3 d image processing knowledge,segmentation and extract contains only LingWu long jujube fruit area of depth image,finally transform it into seven pieces of point cloud model.(3)Study on identification and center location of mark points of LingWu long jujube.Firstly,the collected gray image was smooth-processed,ROI region selection,image cutting,image threshold segmentation,region generation based on contour,connected domain acquisition,morphological operation,feature selection,and then the center of the mark point was accurately located through ellipse fitting,and the center pixel coordinate of the mark point was finally obtained.(4)Study on three-dimensional point cloud reconstruction of LingWu long jujube.First,finding the center of the landmark 3d coordinate by matching the same landmark and three-dimensional coordinate transformation between different perspective coordinate transformation matrix and transformation matrix was applied to seven pieces of point cloud model,and makes six points behind the cloud model is converted to the Angle of the first piece of point cloud model coordinates of integrating it into a complete LingWu long jujube point cloud model.Next,the 3d point cloud reconstruction of LingWu long jujube fruit was completed through simplification,denoising and triangular meshed surface reconstruction,and the operation procedure was only about 15 seconds,with low time complexity.Finally,in order to verify the feasibility and stability of the method in this paper,the three-dimensional reconstruction of 10 LingWu long jujube fruits was carried out and their size was measured to calculate the mean value of size error.The results show that the mean size error is less than 10%in both the length direction and the width direction.