1. A method for diagnostic image reconstruction from projection data comprising: (a) generating projection data; (b) convolving the projection data; (c) scaling the convolved projection data into unsigned fixed precision words of a predetermined number of bits; (d) splitting the words into a predetermined number of color channels corresponding to color channels of a multi-color rendering engine; (e) simultaneously and independently backprojecting the split words along each of the color channels to obtain backprojected views for each color channel; (f) accumulating the backprojected views for each color channel to produce separate color images corresponding to each color channel; and, (g) recombining the separate color images to produce an output image.