Multi-camera reconstruction method based on DLP surface structured light

Abstract

The invention provides a multi-camera reconstruction method based on DLP surface structured light. The multi-camera reconstruction method comprises the steps that a four-eye structured light detection system is built, cameras are calibrated, a PC terminal generates Gray code and phase shift code patterns, a DLP projector is controlled to project, and a level signal triggers the cameras to shoot images obtained after coding patterns are modulated; correcting an image obtained by shooting and carrying out de-noising processing; decoding and unwrapping the de-noised Gray code pattern and the de-noised phase shift coding pattern respectively to calculate a truncation phase, and calculating an absolute phase value by combining the results of the Gray code pattern and the phase shift coding pattern; carrying out stereo matching to obtain point cloud information of the to-be-measured object; filtering the point clouds obtained by the two groups of binocular structured light systems, and preliminarily splicing the two groups of point clouds through rotation and translation transformation; according to the method, the high-precision coding process is completed through combination of the Gray code and the phase-shift code, the coding and decoding accuracy and the final reconstruction precision are improved, and the industrial detection requirement is met.

Description

technical field [0001] The invention relates to the technical field of three-dimensional reconstruction technology, in particular to a multi-camera reconstruction method based on DLP surface structured light. Background technique [0002] The 3D reconstruction technology can be divided into contact type and non-contact type. The contact type 3D reconstruction method mainly obtains the point cloud data of its outline through the direct contact between the sensor and the target object. The detection accuracy of this method is high, but the overall efficiency is low, and at the same time, it may cause certain damage to the object under test during the contact process. Non-contact 3D reconstruction technology mainly obtains the 3D information of the object by contacting the target object through light, sound, electromagnetic waves, etc., or performs 3D reconstruction through the principle of multi-view geometry, and simultaneously shoots through multiple cameras or uses a single...

AI Technical Summary

Problems solved by technology

The photometric stereo method uses a camera and multiple light sources with the same light intensity, changes the direction of the light source, and takes images of the object under different illumination conditions at the same time, and performs three-dimensional reconstruction according to the surface normal information. Poor anti-interference

The time-of-flight method calculates the depth distance on the surface of the measured object by recording the beam propagation time. This method can avoid the influence of obstructions, but the overall accuracy is low

Laser triangulation is to use the camera to collect the line laser of the surface deformation of the object, and then obtain the three-dimensional information of the object according to the principle of triangulation, but because the projection pattern is a straight line, the measurement efficiency is low

The structured light projection method is a 3D reconstruction method that is widely used at present. It has the characteristics of high precision and fast measurement speed. It consists of a structured light projector, but the field of view measured by this method is limited. If you want to get the complete point cloud information, you need to take multiple shots, and some highly reflective objects are likely to cause the lack of point clouds. Therefore, this project plans to use a four-eye structure. Optical technology, through the projection of gray code and phase shift coding pattern to realize the precise coding of each pixel, and combined with point cloud splicing and fusion technology for 3D reconstruction

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