1. A method of imaging an object comprising the steps of: applying imaging energy from a source to the object; detecting imaging energy that has passed through the object by use of a detector; scanning the object with the imaging energy such that the detector collects measured image data that constitutes a Cauchy data set for John's equation; extrapolating from the Cauchy data set to solve John's equation and determine missing cone beam data; and supplying an image of the object based on the measured image data and the determined missing cone beam data.