Measure the center of an image via center-of-mass
The centroid method used is the floating-box center of mass algorithm by Jeff Valenti et al., which has been adopted for JWST target acquisition measurements on orbit. See JWST technical reports JWST-STScI-001117 and JWST-STScI-001134 for details.
HDUlist_or_filename, ext : string, int
boxsize : int
relativeto : string
units : string
CoM : array_like