value of these indicated by dashed lines. (c) Number of pixel assigned per class over number of ARM iterations. The number of DART iterations is 0, and instead we apply $100$ ARM iterations with $2$ initial iterations. The results are based on intermediate segmentations after each 10 ARM iterations, but these segmentations are not used in further iterations. Background pixels are excluded from the results (d) Pixel error over number of ARM iterations for both approaches.[]{data-label="fig:4"}](figure15.eps "fig:"){width="\textwidth"}

[0.48]{} ![Convergence behavior for material classes with $C=10$ channels. (a) Phantom that has been used with $m=4$ materials (b) Graph showing the behavior for each material class in a DART routine for this phantom. The number of iterations for the initial reconstruction is set to $2$, the number of DART iterations is $10$, the number of ARM iterations is set to $10$, the number of angles is $8$, fixing probability is set to $\beta=0.99$. The chosen ARM is SIRT. Shown are the number of pixels assigned per class during segmentation after each DART step, with the true value of these indicated by dashed lines. (c) Number of pixel assigned per class over number of ARM iterations. The number of DART iterations is 0, 