Research On The Comprehensive 3D Information Acquisition Technology Of Objects

In the field of non-contact three-dimensional measurement,the active optical measurement based on structured light is widely used in Machine Vision,Reverse Engineering,Hardware-in-the-loop Simulation and Biomedicine because of high speed,good system flexibility,high-precision.It has a broad prospect to application and of great importance to be studied.Generally,the three-dimensional measurement system which has one camera could only collect the object's point cloud data at a fix view angle.Owing to the factors of surface highlight,shadow,occlusion,and view angle restriction,the point cloud data is incomplete.In recent years it has been a lot of research to solve relevant problems.Hence how to acquire the full surface point cloud data is always a hot topic in the field of three-dimensional measurement.In this paper,we aim at how to collect multi-angle and full surface point cloud data.Our work could be described briefly as follows.1.Because of the shortcoming of low speed measurement,complex system,high calibration standard in the multi-sensor three-dimensional measurement system,we present a high speed simple 360 degree three-dimensional measurement system and a convenient high-precision calibration method.This system consist a projector apparatus,a camera and two front surface mirrors.The point cloud data of the object is obtained from three parts.The front surface part is acquired directly from the camera corresponding to the middle area in the picture,the rest two parts collected respectively from two flat mirrors are the left and right area in the picture.Firstly the system without front surface mirror is calibrated.Afterwards the right and left two systems containing the front surface mirrors can separately be calibrated with a slight double-sided projector screen.We eventually can get a continuous surface point cloud data under the global coordinate.The experimental result which is perfect for field calibration show the low cost to construct the system,calibration of high precision,high speed of reconstruction.2.According to the present methods of three-dimensional depth acquisition,a low-cost three-dimensional measurement system is built by combining structured light projection profilometry with light field recording.In this system,a camera is fixed at the horizontal translation stages.The light field data is collected by moving the camera along the horizontal direction at a fixed distance every time.Meanwhile,the phase shift and gray coded chart figure is acquired.In the four-dimensional light field data,the spatial angular resolution is extremely large because of high camera resolution.We can finally obtain the object point cloud data by means of dealing with the multi-angle absolute phase data using the method of epipolar plane image analysis.There is no need to do some calibrations to the system.It's quite simplify that we can obtain multi-angle data to the object through a one-time experiment.It shows high speed and simple in structure.