aiapsi: Iterative algorithms for PSI with unknown phase shifts

In mlpeck/zernike: Zernike Polynomials

Iterative algorithms for PSI with unknown phase shifts

Description

Three iterative algorithms for PSI with unknown phase shifts.

Usage

aiapsi(im.mat, phases, ptol = 0.001, maxiter=20, trace=1)
aiapsiC(im.mat, phases_init, ptol, maxiter, trace)
hkpsi(im.mat, phases, maxiter = 20, ptol = 0.001,
  trace = 1, plotprogress = TRUE)
tiltpsi(im.mat, phases, coords, ptol = 0.01, maxiter = 20, trace = 1)
tiltpsiC(im.mat, phases, coords, ptol, maxiter, trace)

Arguments

im.mat	a matrix of interferogram values
phases	Starting guess for phase shifts
ptol	Convergence criterion for phase shifts
maxiter	Maximum number of iterations
trace	Boolean: Print some summary data at each iteration.
plotprogress	Plot some summary data for each iteration?

Also, for tiltpsi and tiltpsiC

coords

Low order Zernike polynomial matrix

Details

The “variable tilt“ algorithm now allows an indefinite number of low order Zernike terms to be variable between phase steps. coords can be created with zpm setting maxorder to a small value, say 4, discarding the first (dc) column and retaining as many as desired. There must be at least two columns for tilts. The third will be defocus, the next two astigmatism, the next two primary coma, ...

aiapsi and tiltpsi are wrappers for the calls to the C++ code in aiapsiC and tiltpsiC with sensible defaults for ptol, maxiter, and trace.

Value

A list containing the following elements:

phi	The wrapped phase estimate. This is a vector as long as the number of rows in im.mat.
mod	Modulation estimate.
phases	Phase shift estimates.
iter	Number of iterations.
sse	Sum squared error at each iteration.

Also, for tiltpsi

zcs	Matrix of Zernike coefficients, with one row for each column in coords and number of columns = number of columns of im.mat.

Author(s)

M.L. Peck [e-mail]

References

Zhaoyang Wang and Bongtae Han, “Advanced iterative algorithm for phase extraction of randomly phase-shifted interferograms,” Opt. Lett. 29, 1671-1673 (2004).

Han, G-S and Kim, S-W,, “Numerical correction of reference phases in phase-shifting interferometry by iterative least squares fitting,” Applied Optics 33, 7321-7325 (1994),

Lin, B-J et al., “An iterative tilt-immune phase-shifting algorithm,” OSA conference Optical Fabrication and Testing 2010.

See Also

psifit

mlpeck/zernike documentation built on April 19, 2024, 3:16 p.m.