Robust and efficient multi-frequency temporal phase unwrapping: optimal fringe frequency and pattern sequence selection

Profilometry without phase unwrapping using multi-frequency and four-step phase-shift sinusoidal fringe projection.

A three-dimensional (3D) profilometry method without phase unwrapping is proposed. The key factors of the proposed profilometry are the use of composite projection of multi-frequency and four-step phase-shift sinusoidal fringes and its geometric analysis, which enable the proposed method to extract the depth information of even largely separated discontinuous objects as well as lumped continuou...

Closed-form, robust and accurate multi-frequency phase unwrapping: frequency design and algorithm

A closed-form algorithm, named “concerto”, is proposed for phase-based distance estimation in multi-frequency phase unwrapping (MFPU) system. The concerto method consists of three coherent estimation stages,i.e., initial modified BW estimation, residual error estimation and LS estimation , each of which has a closed-form expression and cooperates closely with each other like a concerto. Due to ...

Efficient Multi-frequency Phase Unwrapping Using Kernel Density Estimation

In this paper we introduce an efficient method to unwrap multi-frequency phase estimates for time-of-flight ranging. The algorithm generates multiple depth hypotheses and uses a spatial kernel density estimate (KDE) to rank them. The confidence produced by the KDE is also an effective means to detect outliers. We also introduce a new closed-form expression for phase noise prediction, that bette...

2-D phase unwrapping and instantaneous frequency estimation

Computationally efficient and robust frequency-domain GSC

In this paper, we propose a novel adaptive beamforming algorithm with low signal distortion capability and high computational efficiency. The proposed algorithm incorporates the crosstalk-resistant adaptive noise canceller (CTRANC) in place of the usual adaptive interference canceller (AIC). Doing so, a better signal leakage estimate is provided at the adaptive interference canceller input but ...