Real-time denoising of ToF measurements by spatio-temporal non-local mean filtering

This work addresses the problem of denoising of range data obtained by ToF continuous signal modulation camera working in low-power mode. The proposed approach is based on non-local mean filtering applied over extensive spatio-temporal block search in complex-valued signal domain. The extensive search allows for using shorter integration times of the range sensors and leads to an effective overcomplete structure suitable for denoising. The filter structure is optimized for real-time operation and achieves O(1) performance for arbitrary patch size by utilizing summed area tables and look-up table data fetching. The experimental results show practically the same performance while compared with state-of-the-art approaches, for greatly improved speed.