为实现动态物体的实时三维测量，提出了一种基于经验模式分解的三频彩色条纹投影轮廓术。将低、中、高三种频率的正弦条纹分别经投影仪红(R)，绿(G)，蓝(B)通道同时投影至被测物面，CCD在另一角度拍摄变形条纹图。将变形条纹图R、G、B三分量互减消减背景干扰，用经验模式分解进行颜色解耦，分离各载频项,进而以傅里叶变换解调相位。以变精度去包裹算法按低、中、高频依次完成包裹相位展开，得到高频载频项的展开相位。计算机模拟时相位解调的标准差小于0.0417 rad，具有较高的测量精度；对比实验和面部表情变化实验进一步说明了方法的可靠性。该方法在单次拍摄下实现了相位的解调及高精度相位的精确展开，为动态物体的高精度轮廓测量提供了有效的手段。

A triple-frequency color-encoded fringe projection profilometry based on empirical mode decomposition is presented to measure the dynamic objects in real time. Sinusoidal fringe patterns of three frames with different frequencies are encoded in red, green, blue (RGB) channels, respectively, projected on the objects by projector at the same time, and the deformed fringe patterns are captured by CCD at another angle. The background components are eliminated after subtracting the red channel′s component from both blue and green components. Then empirical mode decomposition is used for color decoupling and separating the highest, medium and lowest fundamental frequency components. Phases are demodulated by using Fourier transform, and the warpped phase demodulated from the highest fundamental frequency components is unwrapped by three-step phase unwrapping with variable precision algorithm. The simulation experiment, in which the standard deviation of phase demodulation is less than 0.0417 rad, shows the method has high precision. Furthermore, the method is verified to be effective by contrast experiments and experiment on facial expression. It implements phase demodulation and phase unwrapping with high precision based on single snapshot, thus it is very effective to measure 3D surface contour of dynamic objects with high precision.