中文摘要：

向物体投射正交正弦光栅或正弦光栅，都能实现我们提出的高密度全场离焦三维测量，实验发现测量精度依赖于投射模式和物体毒面纹理。计算机模拟显示物体深度测量精度与物体纹理的调制度、频率和投射光栅方向有关。对各种纹理，正交正弦光栅投射的测量精度都高于正弦光栅投射的测量精度。在相同实验条件下，正交正弦光栅和正弦光栅投射的弱纹理表面的深度测量均方误差分别为0．18mm和0．25mm，较强纹理表面的均方误差为0．35ram和0．54mm。

英文摘要：

The method to obtain dense＇full - field depth from defocus with either cross- sinusoidal grating projection or sinusoidal grating projection has been proposed previously by us. In experiment, it has been showed that the precision of the measurement depends on the sort of the grating and the texture characteristics of the object. The computer simulation shows that the precision of active depth from defecus depends on the modulation, frequency and direction of the surface texture of the object. The simulation also shows that, for surfaces with different 2D textures, the precision of the system with cross - sinusoidal grating projection is better than that under sinusoidal grating projection. Under the same experimant conditions, the depth standard deviation, for weak texture surface, is 0. 18mm with cross - sinusoidal grating projection and that is 0. 25mm with sinusoidal grating projection; while for strong texture surface, the depth standard deviation is 0. 35mm or 0. 54mm respectively.