Avoid the 'Inverse Crime' - typo, new graph

Uses 2 different number of pixel for the calculation of the system
matrix, in order to avoid the 'Inverse Crime' based and the advice of M.
Ahlborg, T. Knopp and W. Erbe. See "Introduction into MPI"
% Knopp & Buzug 2011 p140 §5.4.4.
update with new graphs