1. A method for producing an image of a subject positioned in a field of view (FOV) of an imaging system, the steps comprising: a) acquiring with the imaging system a view of the subject positioned in the FOV; b) producing a composite image of the subject which provides a priori knowledge of the subject to be imaged; c) performing highly constrained processing of the view acquired in step a), using the a priori knowledge of the subject embodied in the composite image; and d) repeating step c) a plurality of iterations to produce a final image of the subject in which the image that results during one iteration is employed as the composite image in the next iteration.