依据光栅图像的相位单调增长特性，提出了一种基于最小二乘法的单调光顺算法进行光栅相位误差校正。详细分析了光栅图像的相位单调特性和相位误差，以光栅图像相位的单调性为约束条件，改进了传统的最小二乘拟合方法，对绝对相位图进行相位误差校正。实验结果表明，该方法降低了投影仪伽马非线性造成的相位误差，误差减少60%以上，校正后的绝对相位具有光滑性良好的优点。

Based on monotonous growth characteristics of the phase of grating images, a monotonous smoothing algorithm based on least square method is proposed for phase error compensation. The monotonous characteristics and error of phase are analyzed in detail. Then a monotonous smoothing algorithm based on developed least square method is used to correct phase error of absolute phase diagram. Experimental results show that the gamma nonlinearity of the projector is reduced by more than 60%, and the corrected absolute phase has the advantage of good smooth.