Fig. 15

Time and memory consumption for different algorithms vs. the size of the system matrix for the two models. The top (bottom) row shows the memory (time) consumption. The first, second, and third columns represent the forward projection, backward projection, and OSEM algorithm with six subsets and 12 subiterations. Each plot consists of four different sizes of the system matrix which correspond to different maximum ring differences of 0, 5, 10, and 15