相位编码条纹投影轮廓术的相位展开误差校正方法

Phase unwrapping errors correction for phase-encoding based on fringe projection profilometry

相位编码法是条纹投影技术中常用的一种相位展开方法。然而,受到随机噪声、图像采样、系统离焦等因素的影响,条纹阶次与包裹相位的对应关系容易被破坏,从而引入相位展开误差。根据相位展开误差的分布特点,提出一种附加二值条纹的相位展开误差校正方法。引入的二值条纹与相位编码条纹的码字存在半周期错位,使得计算出的2组条纹阶次值具有互补性,利用两者的互补性可以有效地消除相位展开误差。仿真和真实实验均表明,该方法能够准确地恢复出被测物体的绝对相位,具有较高的可靠性。

Phase-encoding method is a phase unwrapping method commonly used in the fringe projection technology.However,due to the influence of the random noises,image sampling and system defocusing,it is prone to break the corresponding relation between the fringe order and the wrapped phase,which may cause the phase unwrapping errors.According to its distribution characteristics,a phase unwrapping errors correction method with an additional binary fringe was proposed.The half-period dislocation was existed between the codewords of the binary fringe and the phase-encoding fringe,which made the calculated two groups of fringe order values complementary,and the phase unwrapping errors could be effectively eliminated by using the complementary.Both simulation and experimental results show that the proposed method can accurately recover the absolute phase of the measured objects,which has higher reliability.