提出了一种基于外差式多频相移技术的单目结构光扫描系统.将投影过程看作摄像的逆过程,建立投影仪栅片图像和CCD像机图像的对应关系,提出了基于外差式多频相移的投影仪栅片图像生成方法.由拍摄和生成得到的标定图像,基于近景摄影测量原理分步计算出摄像机内参数、投影仪内参数和他们的相对外参数,实现了扫描仪的系统标定.标定实验表明该方法具有较高的标定精度,重投影误差在0.08 pixel以下;扫描实验表明文中单目结构光扫描仪测量标准球的误差小于0.07 mm,能满足一般型面的测量要求.
Proposes a structure-light scanning system based on heterodyne multiple-frequency phase-shift techniques.Considering the projecting process as an inverse process of photography,the corresponding relationship between ‘ gate image’ of projector and CCD image is established,a method of generating the ‘gate image’ of projector is proposed by means of heterodyne multiple-frequency phase-shift techniques.From the CCD image and the generated ‘ gate image’,the interior parameters and the exterior orientation parameters of the camera and projector could be calculated based on close range photogrammetric principle,which means system calibration is implemented.The calibration experiment shows high precision of the calibration method,its re-projection error is lower than 0.08 pixel.The scan experiment shows that the constructed single-camera structure-light scanner can reach accuracy of 0.07 mm when scannig a standard 3D-shape,it can meet general requirements of shape measurement.