Figure 7

(a) Standard messages passing principle of the belief-propagation technique (b) iteration i + 1 of the proposed Hierarchcal Belief Propagation (HBP) based on the k-nearest neighbors having high confidence measure (c) iteration i + 1 of the HBP. The black square points denote pixels having a confidence measure higher than a fixed confidence threshold. The confidence of a given pixel can be upadted at the (ith iteration and then it can be used in the (i + 1)th iteration.