提出了一种对水中物体进行光学投影式表面三维形貌测量的新方法。通常的测量方法都是假设摄像机和被测物体都处于空气中, 测量水中物体时, 由于光在空气、水分界面上发生折射, 投射到被测表面的光条纹图像发生扭曲, 从而给三角测量法带来误差。新方法可以精确测量出水中被测物表面的三维坐标并计算出物体的几何尺寸, 实验验证了该方法的有效性。考虑折射后, 该测量类似于在空气环境中的测量。采用的极线约束及亚像素技术, 提高了测量精度和速度。

A three-dimensional measurement method of objects' shape in water by using light stripe projection is proposed. Usually, three-dimensional measurement is executed under the assumptions that cameras and objects are in aerial environments. However, stripe image distortion occurs when vision sensors measure objects in liquid, for the refraction of the light on the air and water interface, and brings errors in a triangulation. The proposed method can measure accurately three-dimensional coordinates of objects' surface in water, and calculate the geometrical size of the object. The validity of the proposed method is proved experimenally. By considering the refraction of light, the three-dimensional measurement of objects in water becomes same as in air and the measurement has a higher accuracy and speed because of the epipolar constraint and sub-pixel technology.