Processing time-correlated single photon counting data to acquire range images

The processing and analysis are described of range data in a time-of-flight imaging system based on time-correlated single photon counting. The system is capable of acquiring range data accurate to 10 µm at a stand-off distance in the order of 1 m, although this can be varied substantially. It is shown how fitting of the pulsed histogram data by a combination of a symmetric key and polynomial functions can improve the accuracy and robustness of the depth data, in comparison with methods based on upsampling and centroid estimation. The imaging capability of the system is also demonstrated.