为了消除投影仪伽马非线性对相位波动误差的影响，提出了基于八步相移法的伽马非线性误差消除方法。对相位解析表达式进行了数学分析和推导，建立了相位与投影仪伽马值的数学模型，针对投影仪的四阶以内的伽马非线性误差，相位求解表达式消除了伽马非线性系数，消除了伽马非线性对相位的影响。实验结果表明,该方法能有效降低由伽马非线性引起的相位波动误差，相位误差的标准偏差降低为原来的8.3%，标准方差降低为原来的20.5%。该方法简单可靠，不受环境光和系统参数的影响，具有很好的通用性。

In order to eliminate the influence of the gamma nonlinearity of the projector on the phase, this paper proposes a method to remove the gamma nonlinearity based on the eight-step phase shifting. The mathematical analysis and derivation of the phase are demonstrated, and the mathematical model is established between phase and projector gamma. For the gamma nonlinearity error within the four order of the projector, we illustrate that the expression of the phase is independent of the gamma nonlinearity. The experimental results show that the method can effectively reduce the phase error caused by the gamma nonlinearity. The standard deviation of the phase error is reduced to 8.3% of it. Besides, the standard deviation is reduced to 20.5% of it. This method is simple, reliable and universal, and it is not affected by ambient light and system parameters.