An Error-Correction Graph Grammar to Recognize Texture Symbols

This paper presents an algorithm for recognizing symbols with textured elements in a graphical document. A region adjacency graph represents the graphical document, with the nodes being polygons and the edges the neighborhood relations between them. The textured symbols are modeled by a graph, where nodes are polygons (represented by strings) or textured areas (represented by a graph grammar with error-correction rules). The recognition process is done by a graph matching process that uses a string edit distance to recognize the static parts of the symbol and a parsing process that segments the subgraph in the original graph, following the rules of the graph grammar.