Automatic table locating technique for documents

摘要

Table-like structures in documents are located by analysis of sub-regions (crops) on the document. The analysis involves determining the location of lines having lengths above a certain threshold and assigning these lines to groups. A set of adjacent lines is assigned to a common group if the separation between adjacent pairs of lines within the set is less than a threshold value. The crop selected as the location of the table-like structure is that having a group with the greatest number of lines. When the technique is applied to locating title blocks in technical drawings, it is preferred to analyze crops corresponding to the corners or ends of the document. The analysis is also applicable to an image of the document produced at a reduced resolution.