1. A method for three dimensional (3D) computerized topographic (CT) imaging of a region-of-interest (ROI) in an object, comprising: acquiring a plurality of sets of pixels of 2D image data by irradiating the object with energy from a cone beam source that is directed toward a pixelated 2D detector, at a corresponding plurality of scan path source positions located about the object; filtering each of the acquired 2D image data sets so as to develop from the pixel image data of each set a corresponding one of a plurality of filtered 2D images; and 3D backprojecting each of the filtered 2D images into a common 3D space, thereby reconstructing in said 3D space a 3D image of the ROI in the object, wherein said filtering step comprises: dividing the pixels of each set of the acquired 2D image data sets into first and second groups; and separately filtering the first and second groups of pixels so as to independently develop for each group a corresponding image contribution for a given one of the filtered 2D images.