Detector based on the sqrt Airy disk function to localize iSCAT PSFs

[PabloAu]

As an alternative to the DoG detector, it would be very useful to include a new detection method to localize the center of PSFs originated by interferometric imaging methods like iSCAT or COBRI, where the center of PSFs changes from bright to dark depending on the Z-position, and instead of looking similar to a 2D Gaussian, it looks like a first order of a Bessel function of the first kind (with bright and dark rings). (see this publication for reference https://pubs.acs.org/doi/full/10.1021/acsphotonics.7b00238)

The function would be:
PSF(r)=A·(J1(B·r))/(B·r),
Where r is the distance to the center of the PSF, J1(·) is the Bessel function of the first kind of order one, and A and B are variables that describe the amplitude and the width of the PSF, respectively.