GEQM: A quality metric for gray-level edge maps based on structural matching

An accurate quality metric, called GEQM, for gray-level edge maps based on the structural matching of edge pixels is proposed in this work. We design the positional matching cost, which reflects the distance between two edge pixels, and the structural matching cost, which measures the structural shapes of edges as well as the differences of edge strength levels. Based on the cost functions, we perform the graph-cut optimization to obtain the optimal pixel-based matching between source and target edge maps bidirectionally. Finally, we compute the GEQM score by summing up the optimal matching costs of all edge pixels. Experimental results show that the proposed GEQM performs the edge map quality assessment more accurately and more reliably than conventional metrics. Especially, GEQM is suitable for assessing the qualities of synthesized intermediate views in multi-view image processing.