Structural graph-matching approach to image understanding
Gary P. Ford, Jun Zhang · Proceedings of SPIE, the International Society for Optical Engineering/Proceedings of SPIE · 1992
Image understanding is a broad field of image processing where the goal is to classify the elements of a scene. In this paper we describe an approach to image understanding based on the matching of structure graphs. The structure graph of the input image is composed of `nodes' (primitives extracted from the image, e.g., regions, line segments) and `edges' (relationships between primitives in the image). The goal of our algorithm is to find the best match between this graph and a prototype graph, representing the knowledge about the expected scene. We formulate the graph matching problem as a consistent labeling problem, where the nodes of the prototype graph are considered labels. We then search for a labeling of the input structure graph that is optimal in the sense that the nodes and edges of the input graph are consistent with the labels and relationships represented in the prototype graph. A `quality of fit' measurement is derived for the matching, and a genetic algorithm is used to find the optimal solution. The advantages of this method of inexact (or fuzzy) matching include its graceful degradation (robustness) in the presence of noise and image deformation, its parallelism, and its adaptability to a variety of domains. We complete this work with the discussion of experimental results.