Modification of the Snesim Algorithm

Snesim is an algorithm for simulating complex structures. It is a pixel based method that sequentially simulates the nodes in a random order, while considering multipoint statistics. The conditional probabilities are extracted directly from a training image. If a configuration of the set of conditioned nodes is not found in the training image, the set is decreased node by node until the configuration of the final set is found. <br>We have modified the Snesim algorithm by enabling it to also delete nodes, i.e. instead of just removing nodes from the set of conditioning nodes we let the set remain intact but delete the values of the relevant nodes. When all nodes are visited, the deleted nodes are revisited in a second iteration, and this is repeated until all nodes are sampled.<br> For a training image consisting of channels, the modified algorithm has shown improved results. The original Snesim algorithm had problems with loose end channels, and with the modified algorithm the number of loose ends has decreased significantly. The number of iterations required for the simulations of the modified algorithm is insignificant, and only an increase of 23% of the total number of nodes had to be re-sampled. <br>