成像过程中的CCD噪声将给图像测量结果带来误差,因此能否有效地抑制这些噪声是提高测量精度的关键。分析了CCD暗电流噪声和随机噪声的特性,并针对各自特性提出了相应的噪声标定技术以及抑制方法。结合精密图像测量任务,分别研究了暗电流噪声和随机噪声对一维边缘定位、结构光相移法相位提取的影响。通过仿真和实验,比较了噪声抑制前后的测量结果,结果表明,噪声抑制后边缘定位精度有很大的提高,证实了该CCD噪声标定技术和抑制方法的有效性和必要性。

The CCD noise from imaging process brings error to the results of optical measurement, so that noise suppression is a key to improve measurement accuracy. The characteristic of dark current noise and random noise is analyzed, and noise calibration and suppression techniques to each component are proposed respectively. The influence of CCD noise on optical measurement tasks, such as edge location and phase extraction of structural-light phase-shift method, is investigated. Simulation and experimental results show that the edge location accuracy is greatly improved by means of CCD noise calibration and suppression. Therefore, the validity and necessity of the proposed method is well confirmed.