中文摘要：

将两步广义相移法引入投影栅形貌测量，提出了一种两步广义相移的投影栅轮廓术。首先将2幅随机相移正弦条纹通过DLP投影仪投射到待测物体上，由CCD相机采集受物体形貌调制的变形光栅条纹图；然后选择合适大小窗口经像素逐点均值法消除变形栅线图中的背景成分，利用栅线图灰度利用极值法、亚像素插和多点平均算法，准确提取2幅随机相移栅线图的相移量；最后由求得的相移量和2幅消除了背景成分的栅线图，计算出与形貌对应的相位数据。进行了实际测量，结果表明本文方法的可行性。

英文摘要：

A projection profilometry by two-step generalized phase-shifting is proposed after the two-step generalized phase-shifting algorithm is introduced into the three-dimensional （3D） shape measurement. Firstly,two phase-shifted randomly sinusoidal fringe patterns are projected onto the tested object by a digital-light-processing （DLP） projector. The fringe patterns modulated with the object＇s surface are captured by a CCD camera. Secondly, the background component is eliminated from deformed gratings by averaging method pixel by pixel after the appropriate window size is chosen,and the phase step between two phase-shifted randomly sinusoidal fringe patterns is determined by subpixel interpolation,extremma of the fringe and multi-point average method. Then, the phase is extracted from the defromed patterns without the respective backgrounds by the step value. Finally, the experimental evaluation is conducted to prove the validity and performance of the proposed method. The experimental result is analyzed and compared with that of other methods. The effectiveness and superiority of the proposed method are also demonstrated.