this implements a very simple distortion correction following The Double Sphere Camera Model Vladyslav Usenko, Nikolaus Demmel and Daniel Cremers.
inputthe input imageoutputthe output image after applying lens distortion
centermove the center of the projectionscalescale the image larger or smallersquish0the radius of one of the spheressquish1the other radius used for the mappingca redsome fake chromatic aberration correction, just scales the red image planeca bluesome fake chromatic aberration correction, just scales the blue image plane