3.4.1.2 Median Filter

The temporal median filter samples by feeding data into a FIFO, sorting the buffer values, and taking the median value as the output. This effectively removes the extreme values, or noise, if the noise is characterized by intermittent spikes of extreme values. In ToF cameras, the “flying-pixels” effect can be reduced by this filter. The default dead band threshold is 0.05 (5%); that means if the new filtered value differs from the current value by less than 5%, the pixel does not change. This has a stabilizing effect on the output image.

Figure 18. Temporal Median Filter Algorithm (Left) and Properties (Right)