Character recognition method
First Claim
1. A method for recognizing a character string comprising one or more alphanumeric characters read from a document, said character string being defined by a first end and a second end, each of the alphanumeric characters comprising a plurality of structural elements disposed with a predetermined geometrical relationship so as to form the alphanumeric character, said method comprising the processes of:
- (a) providing a dictionary having each alphanumeric character stored as a graph, the graph comprising nodes and links connecting the nodes;
(1) each of the nodes corresponding to one of the structural elements and carrying an attribute representative thereof; and
(2) each of the links representing the geometrical relationship which exists between the nodes which are connected by the link;
(b) reading a character string from a document;
(c) extracting one or more structural elements and a geometrical relationship existing therebetween from the character string read from the document, starting from a starting location of character recognition at the first end of the character string and proceeding consecutively to the second end of the character string;
(d) verifying that the structural elements and the geometrical relationship extracted in the process of extraction exist in the dictionary, wherein said step of verifying includes searching the dictionary;
(1) starting from a simple alphanumeric character having a small number of structural elements; and
(2) proceeding to complex alphanumeric characters having a large number of structural elements;
(e) predicting the structural elements and the geometrical relationship existing in the character string at a location immediately adjacent to the former location in the character string, based on the result of the process of verification, by assuming a candidate character; and
(f) recognizing the character string by moving the location step by step consecutively along the character string towards the second end, while repeatedly performing the processes of extraction, verification, and prediction in each of the steps.
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Accused Products
Abstract
A method for recognizing a character string made of alphanumeric characters comprises processes of providing a dictionary storing each alphanumeric character in a form of a graph including nodes and links, each of the nodes corresponding to the structural elements of the character and carrying an attribute representing thereof, each of the links representing the geometrical relationship which exists between the nodes connected by the link, extracting the structural elements together with the geometrical relationship existing therebetween from the character string read from the document starting from a starting location at one end of the character string, verifying that a corresponding structural element and geometrical relationship exist in the dictionary, predicting the structural elements and the geometrical relationship existing in the character string at a location immediately adjacent to the former location in the character string, based on the result of verification, and recognizing the character string by moving the location step by step consecutively along the character string towards the second end.
41 Citations
5 Claims
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1. A method for recognizing a character string comprising one or more alphanumeric characters read from a document, said character string being defined by a first end and a second end, each of the alphanumeric characters comprising a plurality of structural elements disposed with a predetermined geometrical relationship so as to form the alphanumeric character, said method comprising the processes of:
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(a) providing a dictionary having each alphanumeric character stored as a graph, the graph comprising nodes and links connecting the nodes; (1) each of the nodes corresponding to one of the structural elements and carrying an attribute representative thereof; and (2) each of the links representing the geometrical relationship which exists between the nodes which are connected by the link; (b) reading a character string from a document; (c) extracting one or more structural elements and a geometrical relationship existing therebetween from the character string read from the document, starting from a starting location of character recognition at the first end of the character string and proceeding consecutively to the second end of the character string; (d) verifying that the structural elements and the geometrical relationship extracted in the process of extraction exist in the dictionary, wherein said step of verifying includes searching the dictionary; (1) starting from a simple alphanumeric character having a small number of structural elements; and (2) proceeding to complex alphanumeric characters having a large number of structural elements; (e) predicting the structural elements and the geometrical relationship existing in the character string at a location immediately adjacent to the former location in the character string, based on the result of the process of verification, by assuming a candidate character; and (f) recognizing the character string by moving the location step by step consecutively along the character string towards the second end, while repeatedly performing the processes of extraction, verification, and prediction in each of the steps. - View Dependent Claims (2, 3, 4, 5)
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Specification