Study Of Depth Sensing Based On De Bruijn And Phase Coding

With the development of technologies,traditional 2D imaging techniques can not satisfy the need any more.How to acquire dense and accurate depth map at high speed is a key research topic.Among the various depth sensing approaches,the Structured Light methods are widely used.In this paper,we carry out research into the existing depth acquisition technologies and propose two novel phase-coding based methods.In the beginning,we review the background knowledge and introduce the algorithms of structured light methods.According to the existing structure light coding method,we proposed a hybrid coding strategy based on the phase shifting and De Bruijn coding method.The basic idea is to embed the De Bruijn code into the three-step phase shifting patterns.The periods of the fringe patterns can be recovered by the De Bruijn code.Therefore,the phase ambiguities can be solved and the reliable depth can be calculated.Using the theoretical minimum of only three patterns,the proposed method greatly facilitates the application of phase shifting in time-critical conditions.In terms of the performance,the proposed method can improve the calculation speed and the robustness of the traditional phase shifting method.In order to realize real-time and dense depth acquisition for dynamic scenes,we proposed another one-shot phase-coding structured light method.This method adopts intensity information for phase encoding and the color information for the De Bruijn encoding.The De Bruijn encoding is used to eliminate the phase ambiguity.A procedure is proposed to overcome the measurement sensitivity caused by the De Bruijn coding.The practical experiment results show that this method is robust to objects with sharp edges or discontinuous depth.And the proposed method is easier for hardware implementations.At the end of this paper,we summarize all the work and raise prospects for the further research.