Apparatus, method, and computer program for analyzing document layout

A document layout analyzing apparatus for analyzing layout of text on a document image to extract text blocks for character recognition purposes, the apparatus comprising:

• an extraction condition memory to store a plurality of extraction conditions for use in extracting text blocks from a given document image;
• a text block extractor to extract a first set of non-overlapping text blocks from the given document image in accordance with one of the extraction conditions stored in said extraction condition memory, as well as extracting a second set of non-overlapping text blocks from the same document image in a different way from the first set, in accordance with another of the extraction conditions;
• and
• a text block consolidator to produce a consolidated set of text blocks by performing character recognition on each text block extracted by said text block extractor, evaluating validity of each text block based on a result of the character recognition, creating a consolidation source set by finding a text block of the first set which overlaps with a text block of the second set, adding both of those text blocks to the consolidation source set, and repeating operations of finding a text block of the first and second sets which overlaps with any of the text blocks belonging to the consolidated set and adding the found text block to the consolidation source set, and selecting a most valid combination of non-overlapping text blocks from among the text blocks belonging to the consolidation source set, based on the validity of each text block that has been evaluated.

A document layout analyzing method for analyzing layout of text on a document image to extract text blocks for character recognition purposes, comprising:

• storing a plurality of extraction conditions;
• extracting a first set of non-overlapping text blocks from the document image in accordance with one of the stored extraction conditions;
• extracting a second set of non-overlapping text blocks from the same document image in a different way from the first set, in accordance with another of the extraction conditions;
• performing character recognition on each extracted text block of the first and second sets;
• evaluating validity of each text block of the first and second sets, based on a result of the character recognition;
• creating a consolidation source set by finding a text block of the first set which overlaps with a text block of the second set, adding both of those text blocks to the consolidation source set, and repeating operations of finding a text block of the first and second sets which overlaps with any of the text blocks belonging to the consolidated set and adding the found text block to the consolidation source set;
• and
• producing a consolidated set of text blocks by selecting a most valid combination of non-overlapping text blocks from among the text blocks belonging to the consolidation source set, based on the validity of each text block that has been evaluated.