>Psychtoolbox>PsychOptics

LSFToPSF Convert a line spread function to a point spread function.
psf = LSFTOPSF(lsf,varargin)

This works by taking the lsf into the one-dimensional frequency domain
(i.e. get the 1D MTF) and then creating a circularly symmetric version
of this. The 2D frequency representation is then converted back to the
spatial domain to produce the psf. This produces a spatially-symmetric
PSF consistent with the measured line spread function.

This method is described by Marchand, 1964, JOSA, 54, 7, pp. 915-919
and is one of several methods provided. In 1964, taking the Fourier
transform was computationally intense.

There is a second paper by Marchand (1965, JOSA, 55, 4, 352-354) which
treats the more general case where you have line spread functions for
many orientations and want to recover an psf that is not necessarily
spatially-symmetric.

The lsf must be spatially symmetric. This makes sense given that we
are going to recover a spatially symmetric psf.

You want to make sure that the spatial suport is large enough to
capture the full lsf.

The returned psf is normalized to have unit volume.

See also PSFTOLSF, PSYCHOPTICSTEST