设计由两个红外相机和一个紧凑散斑结构光投射器构成的三维人脸采集系统,可根据采集精度和运算效率的折衷配置采集散斑图像。散斑模板固定在垂直于投射器光轴的齿轮上,使用齿轮机构驱动散斑模板作旋转运动,使用波长为735 nm的LED照亮散斑,在测量空间中形成时间和空间上互不相关的散斑编码结构光图案,采用时空相关立体匹配算法实现人脸三维重建。通过理论分析和实验验证散斑模板的旋转角度对测量精度的影响,进而确定最佳的旋转角度。采用德国ATOS高精度工业3D扫描仪获取人脸面具三维数据并将其作为真值,同时测试真实人脸的三维采集效果。实验结果表明,当投射散斑数量为5时,三维重建的平均误差为0.063 mm,误差标准差为0.111 mm。

A three-dimensional face acquisition system consisting of two infrared cameras and a compact speckle structure light projector is designed. The speckle projection system can be configured to project speckles according to the acquisition accuracy and efficiency. The speckle template is fixed on a gear that is perpendicular to the optical axis of the projector, and a gear mechanism is used to drive the speckle template for rotation. The speckle is illuminated by an LED with a wavelength of 735 nm to form a temporally and spatially uncorrelated speckle-encoded structured light pattern in the measurement space, and a spatial-temporal correlation stereo matching algorithm is used to achieve three-dimensional face reconstruction. Through theoretical analysis and experiments, the influence of the rotation angle of the speckle template on the measurement accuracy is verified, and the best rotation angle is determined. The German ATOS high-precision industrial three-dimensional scanner is used to obtain the three-dimensional data of the face mask and use it as the true value, while testing the three-dimensional acquisition effect of the real face. The experimental results show that when the number of projected speckles is 5, the average error of three-dimensional reconstruction is 0.063 mm, and the standard deviation of error is 0.111 mm.