1. A method ( FIG. 5A ) for creating a pixel image {circumflex over (f)} from projections (q 1. .. q p ) comprising the steps of: (a) producing ( 100 ) intermediate-images (I 1 , P) from selected projections (q 1. .. q p ); (b) performing digital image coordinate transformations ( 102 ) on selected intermediate-images (I 1 , P), the parameters of coordinate transformations being chosen to account for view-angles of the projections from which the intermediate images have been produced, and for the Fourier characteristics of the intermediate-images; (c) aggregating subsets of the transformed intermediate-images ( 104 ) produced in step (b) to produce aggregate intermediate-images (I 2 , P/2); and (d) repeating steps (b), and (c) in a recursive manner until all of the projections and intermediate images have been processed and aggregated to form the pixel image {circumflex over (f)}; wherein the coordinate transformation parameters are chosen so that the aggregates of the intermediate-images ( 104 ) may be represented with desirable accuracy by sparse samples.