基于单频四步相移条纹投影的不连续物体三维形貌测量

提出了基于单频四步相移条纹投影的不连续物体三维形貌测量方法。由计算机产生相移步长为π/2的4幅正弦条纹图像,利用液晶投影仪投影到被测物体表面,由CCD相机同步采集获得含有形貌信息的畸变条纹图并保存在计算机中,通过四步相移算法获得条纹相位信息。对于表面形貌不连续的物体,通过4幅畸变条纹图灰度算术和运算并进行二值化处理定位阴影或暗背景,利用二值图像修正解调的相位从而得到正确相位。实验结果验证了本方法的有效性。

3D shape measurement of discontinuous objects based on single frequency fringe projection in 4-step phase shifting profilemetry

A new single-frequency fringe projection profilometry for discontinuous shape measurement is proposed.Four-step sinusoidal fringe patterns with phase increment of π/2 generated by computer are projected onto the object surface by a digital video projector and the deformed fringe patterns are acquired by a CCD camera.The captured fringe patterns are firstly employed to extract phase information.Sum operation is then applied on four deformed fringe patterns to remove fringes and determine the shadow and dark background.The sum image of four fringe patterns is binarized and used for the phase correction.The experimental results demonstrate the validity of the proposed method for discontinuous shape measuring.