基于格雷码和多步相移法的双目立体视觉三维测量技术研究

3D Measurement Technology Based on Binocular Stereo Vision Using Gray Code and Multi-Step Phase-Shift Structured Light

摘要:

传统的被动式双目立体视觉三维测量技术，具有操作简单，使用灵活方便，相机标定技术成熟的优点，但是对于特征点稀疏图像，寻找匹配点困难，匹配精度低。编码结构光测量方式通过向待测物体投射特定的编码图案，获取编码图像进行解码求解物体的三维信息，具有着测量精度高，速度快的优点，但是存在着投影仪标定精度低，实现难度大的缺点。提出了将双目立体视觉和编码结构光相结合的三维测量方法，在完成双目校正的基础上，向待测物体投射格雷码图案和多步相移图案，给予被测物体容易识别和可控制的特征信息，最后求取物体的三维信息。而且通过实验论证了投射多步相移图案比起4步相移图案，测量精度更高，能够更好的体现物体细节。

关键词:3D测量;双目立体视觉;编码结构光;格雷码;多步相移法

Abstract:

The traditional passive binocular stereo vision three-dimensional measurement technology has the advantages of simple operation, flexible and convenient use, and mature camera calibration technology, but it is difficult to find matching points ,and the matching accuracy is low for images with sparse feature points. The encoded structured light measurement method acquires the encoded image by decoding a specific coding pattern to the object to be measured, and decodes the three-dimensional information of the object. It has the advantages of high measurement accuracy and high speed, but it has the disadvantages of low calibration accuracy and difficult to realize. The 3D measurement method combining binocular stereo vision with coded structured ligh, based on completing the binocular correction to the object projection, gray code patterns and multi-step phase-shift pattern to the measured object can be easily identified and controlled feature information, finally obtain three-dimensional information of objects. Moreover, it is proved by experiment that projective multi-step phase-shifting pattern is more accurate than 4 step phase shifting pattern, and can reflect object details better.

Key words:3D measurement; Binocular stereo vision; Structured light;Gray-code; Multi-step phase-shift