Related Experiment Video
Updated: Jul 12, 2026

The Frequency Domain Thermoreflectance Technique for Thermal Property Measurements
Published on: December 5, 2025
Robust Three-Frequency Number-Theoretical Temporal Phase Unwrapping for Phase-Differencing Profilometry
Abstract:
Achieving three-dimensional (3D) imaging with high flexibility and high robustness has long been a challenge for fringe projection profilometry (FPP). In order to address this challenge, a three-frequency number-theoretical temporal phase unwrapping (TFNT-TPU) method for phase-differencing profilometry (PDP) is proposed. By utilizing the isophase closure feature of the wrapped phase difference just caused by the measured object itself and the loose constraint relationship among the gratings with three different frequencies, 3D imaging with high flexibility can be achieved. Furthermore, to further enhance the error resistance and robustness of the proposed TFNT-TPU, an optimized design scheme for the parameters is established to suppress random errors. Additionally, a self-correction strategy is also proposed to suppress computing errors caused by arctangent operation. A series of theoretical analyses and experiments demonstrate that the 3D imaging with high flexibility and high robustness can be achieved by the proposed method.
Related Concept Videos
Time and frequency -Domain Interpretation of Phase-lead Control
The design of phase-lead control involves the strategic placement of poles and zeros to balance steady-state error and system...
Time and frequency -Domain Interpretation of Phase-lag Control
Phase-lag controllers do not place a pole at zero, but instead influence the steady-state error by amplifying any finite,...
IR Frequency Region: Fingerprint Region
The...
IR Spectrum Peak Splitting: Symmetric vs Asymmetric Vibrations
Linear Approximation in Frequency Domain
In contrast, nonlinear systems do not inherently possess these properties. However, for small deviations around an operating point, a nonlinear system can often be approximated as linear.
IR Frequency Region: X–H Stretching

