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What is it about?

Usually, phase-shifting algorithms assume that the phase shift is a linear function of time and space. Unfortunately, this requirement is not always satisfied in practice.

Why is it important?

This paper proposes a phase-shifting algorithm used when the phase shift is unknown and nonlinear in both time and space. Particularly, this algorithm is suitable in practice when nonlinear or miscalibrated phase shifters are used. Due to the useful properties of this algorithm such as the robustness, computational efficiency, and user-free execution, this proposal could be used in automatic applications.

Perspectives

This approach overcomes two hard constraints regarding conventional phase-shifting methods.

• First, the proposed approach works with a minimum of two or more fringe patterns instead of three required by conventional methods.
• Second, the phase shifts can be unknown functions of space and time, in contrast with conventional methods where the phase shifts must be known constants.

The unique properties of the proposed method provide an advanced framework for specialized phase-shifting applications.