Frequency selection in continuous wave indirect Time of Flight cameras

Continuous wave indirect Time-of-Flight cameras obtain depth images by emitting a modulated continuous light wave and measuring the delay of the received signal. The wave is modulated sequentially using multiple frequencies. In this paper, a new algorithm for the identification of the optimum set of frequencies is presented. The optimization problem is modeled with multiple objective criteria: minimising the number of unwrapping errors and maximising the distance estimation precision under given constraints such as the maximum modulated frequency or the minimum unambiguous range of working distances. The dependence of the proposed optimization on each constraint and the performance of the method are analyzed using Montecarlo simulations.