Entity Clustering Using 3D Mesh Simplification

Entity clustering is a vital feature needed by any automatic content conversion system. Such a system constructs a digital document from a hard copy of a newspaper, book, etc. At application level, the system will process an image (typically black and white) and identify the various content layout elements, such as paragraphs, tables, images, columns, etc. Here is where the entity clustering mechanism comes into play. Its role is to group atomic entities (characters, points, lines) into layout elements. To achieve this, the system can take on different approaches. They mostly rely on the geometrical properties of the enclosed items, like their relative position, size, boundaries or alignment. This paper describes an approach based on 3D mesh reduction algorithms. Key-Words: automatic content conversion, document digitization, layout identification, entity clustering, mesh reduction, heightmaps, terrain, level of detail