REPROJECTION AND BACKPROJECTION METHODS AND CORRESPONDING IMPLEMENTATION ALGORITHMS

摘要

Methods for projecting and backprojecting rays with respect to pixels/detector bins to attenuate/eliminate high-frequency artifacts, are disclosed. The first two methods are adaptations of pixel-driven and ray-driven linear interpolation techniques respectively. In these techniques, the window or shadow of each pixel/bin is dynamically adjusted and projected onto the detector bin/pixel to eliminate gaps between the shadows. This allows the effect of each pixel on a given detector bin (or vice versa) to be appropriately weighted. A third is a distance-driven technique wherein the transitions of the pixels and the detector bins are respectively projected onto a common axis. This allows a determination of the contribution of each of the pixels/bins for each of the bins/pixels with lower computation time and improved artifact free images.