基于条纹投影的连续相位自适应补偿方法

Adaptive Compensation for Continuous Phase Based on Fringe Projection

针对格雷码相移条纹投影三维测量中相位展开易出现跳跃错误的问题,提出一种连续相位自适应补偿方法。该方法基于双目结构光三维测量系统,采用相移法结合正反格雷码的方法得到待测物体的连续相位图,在连续相位图上搜寻错误像素点,最后利用改进的自适应中值滤波方法来补偿相位展开出现的跳跃错误像素点以及噪声和阴影生成的无效像素点。实验结果表明:连续相位自适应补偿方法相对于传统格雷码相移法以及在连续相位图使用固定值中值滤波方法能够补偿连续相位图中大部分的错误像素点,并尽可能地保留待测物体的细节,提高了三维形貌测量的稳定性和精度。

Aiming at the jumping error of phase unwrapping in gray code phase-shifting fringe projection 3D measurement,an adaptive compensation method for continuous phase is proposed.Based on the binocular structured light 3D measurement system,the continuous phase map of the object to be measured is obtained through the phase-shifting method in combination with the positive and negative gray code method.Then,the wrong pixels are searched for on the continuous phase map.Finally,the improved adaptive median filter method is used to compensate for the jumping error pixels in phase unwrapping and the invalid pixels generated by noise and shadow.The experimental results show that in comparison with the traditional gray-code phase-shifting method and the method of applying fixed-value median filter to continuous phase map,the proposed method can compensate for most of wrong pixels on the continuous phase map while retaining the details of the object to be measured as much as possible,which improves the stability and accuracy of 3D topography measurement.