1. A diagnostic imaging system, comprising: a means for re-binning projection data into a parallel ray format; a means for filtering the parallel ray format data with each of a plurality of different filter channels; a means for convolving the data filtered with each of the filter channels; a means for weighted averaging readings which contribute to each voxel ν at an angle θε[0, π); a means for determining actual noise reduction factors to be produced by the weighted averaging; and a means for weighting the convolved data for each of the filter channels based on the channels' noise reduction factors, and the determnined actual noise reduction factors.