Character recognition method and apparatus, including generation of a degree of belief

An apparatus for recognizing characters, comprising:

• a) input means for inputting image data which represents characters;
• b) recognizing means for generating a plurality of qualitatively distinct recognition outputs for each of said characters based upon a plurality of distinct processes which rely upon independent characteristics for recognizing said characters, said qualitatively distinct recognition outputs defining certainty factors and including ranks and probabilities;
• c) converting means for converting certain of said certainty factors to converted certainty factors;
• and
• d) determining means for determining a degree of reliability for each of said characters based upon said converted certainty factors.

A method for recognizing characters, comprising the steps of:

• (a) inputting image data for characters;
• (b) carrying out a recognition process for recognizing each of the characters based on the image data input in said step (a), said recognition process including at least two of the following distinct processes each of which is applied to each character:
• (1) a segmentation process which extracts image data for each character from said input image data,
• (2) a pattern matching process in which a characteristic feature derived from a character to be recognized is compared with a stored reference feature so as to compute a degree of similarity,
• (3) a path selecting process with which an optimum combination of images for the respective characters in the input image are selected,
• (4) a rule process which applies predetermined rules regarding relationships of respective characters in the input image data and characteristics of respective characters in the input image data, and
• (5) a language process with which a morphological analysis is carried out with respect to the respective characters in the input image data, each of said distinct processes generating a qualitatively distinct result regarding each character, each said qualitatively distinct result defining confidence factors, and wherein a recognition result with respect to each character is determined based on the qualitatively distinct results generated in said distinct processes;
• (c) generating converted certainty factors based on said qualitatively distinct results obtained by said distinct processes, each of said converted certainty factors describing certainty with respect to the result obtained in each of said distinct processes carried out in said step (b);
• and
• (d) performing operations of the converted certainty factors corresponding to said plurality of distinct processes so as to generate combined certainty data, the converted certainty factors being those generated in said step (c), the combined certainty data describing certainty with respect to the recognition result determined in said step (b).

An apparatus for recognizing characters, the apparatus comprising:

• (a) input means for inputting image data for characters;
• (b) recognizing means for recognizing each of the characters based on the image data input by said input means, said recognizing means including at least two of the following distinct processing means each of which operates on each character:
• (1) a segmentation process unit which extracts image data for each character from said input image data,
• (2) a pattern matching process unit in which a characteristic feature derived from a character to be recognized is compared with a stored reference feature so as to compute a degree of similarity,
• (3) a path selecting process unit with which an optimum combination of images for the respective characters in the input image data are selected,
• (4) a rule process unit which applies predetermined rules regarding relationships of respective characters in the input image data and characteristics of respective characters in the input image data, and
• (5) a language process unit with which a morphological analysis is carried out with respect to the respective characters in the input image data,
• each of said distinct processing means generating a qualitatively distinct result regarding each character, each said qualitatively distinct result defining confidence factors, and wherein a recognition result with respect to each character is determined based on the qualitatively distinct results generated in said distinct processes;
• (c) certainty data item generating means for generating converted certainty factors based on said qualitatively distinct results obtained by said plurality of distinct processing means, each of said converted certainty factors describing certainty with respect to the result obtained by each of said distinct processing means;
• and
• (d) operation means for performing operations on the converted certainty factors corresponding to said distinct processing means so as to generate combined certainty data, the converted certainty factors being those which were generated by said certainty data item generating means, the combined certainty data describing certainty with respect to the recognition result determined by said recognizing means.