A fast algorithm for bottom-up document layout analysis

This paper describes a new bottom-up method for document layout analysis. The algorithm was implemented in the CLIDE (Chemical Literature Data Extraction) system, but the method described here is suitable for a broader range of documents. It is based on Kruskal's algorithm and uses a special distance-metric between the components to construct the physical page structure. The method has all the major advantages of bottom-up systems: independence from different text spacing and independence from different block alignments. The algorithms computational complexity is reduced to linear by using heuristics and path-compression.