`DigitalHolography.GeneralizedPSDH`

— Method`GeneralizedPSDH(I)`

return object wave extracted by the generalized phase-shifting method. See (Creath, 1988), (Schreiber and Bruning, 2006). Store N interferograms in a three-dimensional array as `I[:,:,1]`

, `I[:,:,2]`

, ..., `I[:,:,N]`

. Phase difference $\delta_{n}$ corresponding to the n-th interferogram is assumed to be $\delta_{n} = \dfrac{2\pi}{N}n$.

`DigitalHolography.PSDH2`

— Method`PSDH2(I₁, I₂, Iᵣ, δ)`

return object wave extracted by the two-step phase-shifting method (see Ref. 1).

**Arguments**

`I₁`

,`I₂`

: Interferograms corresponding to phases $\phi$ and $\phi - \delta$, respectively.`Iᵣ`

: intensity of reference wave.`δ`

: phase difference $\delta$.

`DigitalHolography.PSDH3`

— Method`PSDH3(I₁, I₂, I₃, δ)`

return object wave extracted by the three-step phase-shifting method (see Ref. 1, 2). Phases of `I₁`

, `I₂`

, and `I₃`

correspond to $\phi - \delta$, $\phi$, and $\phi + \delta$, respectively.

`DigitalHolography.PSDH4`

— Method`PSDH4(I₁, I₂, I₃, I₄)`

return object wave extracted by the four-step phase-shifting method. See (Creath, 1988), (Schreiber and Bruning, 2006). Phase difference `δ`

corresponding to `I₁`

, `I₂`

, `I₃`

, and `I₄`

are assumed to be $\delta = 0, \dfrac{\pi}{2}, \pi$, and $\dfrac{3\pi}{2}$, respectively.

`DigitalHolography.ParallelPSDH`

— Method`ParallelPSDH(I)`

return object wave extracted by the parallel four-step phase-shifting method (see Ref. 1, 2). Using 2x2 pixels with phase differences of $\dfrac{\pi}{2}$ each as units, the object wave is extracted through the four-step phase-shifting method.

- Y. Awatsuji, M. Sasada, and T. Kubota, "Parallel quasi-phase-shifting digital holography," Appl. Phys. Lett.,
85, 1069-1071 (2004).- Yasuhiro Awatsuji, "Parallel Phase-Shifting Digital Holography," in Bahram Javidi, Enrique Tajahuerce, Pedro Andrés (eds.),
Multi-Dimensional Imaging, John Wiley & Sons, Ltd, pp. 1-23