Resolving transient time profile in ToF imaging via log-sum sparse regularization

Multi-frequency time-of-flight (ToF) cameras have been used to recover the transient time profiles of optical responses such that multipath interference can be separated. The resolution of the recovered time profiles is limited by the highest modulation frequency. Here, we demonstrate a method based on log-sum sparsity regularization to recover transient time profiles of specular reflections. We show that it improves the ability of separating pulses better than the state-of-the-art regularization methods. As an application, we demonstrate the encoding and decoding of hidden images using mirror reflections.