一种基于希尔伯特变换实施相移的相位解调算法

A kind of calibration algorithm of phase-shifting based on Hilbert transform

相移法因其精度高、运算简单,所以被广泛应用于形貌检测中的相位解调。该方法的弱点是:不仅要采集多幅相移图像,而且不能克服相移器的移相误差。将小波分析与希尔伯特变换结合起来,采用小波分析去除直流背景成分,利用希尔伯特变换方法实现90°相移;利用相移法解调形貌相位,由于是采用软件来实现相移的,因此只需采集一幅变形栅线图。对该方法与传统相移技术进行了模拟比较实验,结果表明,该方法具有较高的精度。

Phase shift is used to phase demodulation in 3D measurements because of its high precision and simple computation, but it has some disadvantages, such as capturing many frames images, error of shifter. A novel technique of combination with wavelet transforms and Hilbert transform is introduced. The background components are removed by wavelet transform, 90-degree phase shift is obtained by Hilbert transform, the phase demodulation is finished by phase shift theory. Only capturing one frame image is needed. The result of 3D experimental measurement is provided. The result shows that the new technique is reasonable. The simulated experiments are studied with this method and traditional phase-shift method, the result shows that this method has better accuracy.