pupil.pars: Pupil parameters

In mlpeck/zernike: Zernike Polynomials

Pupil parameters

Description

Interactively determine the center, radius, and obstruction fraction of a circular or annular interferogram image.

Usage

pupil.pars(im = NULL, obstructed = FALSE)

Arguments

im	A matrix containing an interferogram image
obstructed	Logical: is there a central obstruction?

Details

In pupil.pars, if the image has already been plotted im can be NULL, which is the default.

Value

A list with the following components:

xc	X coordinate of the center of the pupil
yc	Y coordinate of the center of the pupil
rx	Horizontal radius of the pupil
ry	Vertical radius of the pupil
obstruct	Obstruction fraction

Note

pupil.pars uses the basic graphics library routine locator to interactively mark the edge of the pupil, and optionally the edge of the obstruction. After right clicking to terminate locator() a least squares fit is performed to the marked points to determine the center and radius of the pupil.

Note that all routines that make use of Zernikes implicitly assume a circular pupil, or an annular one with small obstruction. We allow rx != ry for imaging sensors with non-square aspect ratios.

Author(s)

M.L. Peck [e-mail]

See Also

Many routines require the pupil parameters in the form returned by pupil.pars. For example psifit, fftfit, pupil, etc.

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