The uncertainty of character cutout or character recognition is modeled as a directed graph called a character string hypothesis, and this is analyzed by notation knowledge based on quasi-regular expression to determine a character string. 文字切出や文字認識の不確定さを文字列仮説と呼ばれる有向グラフとしてモデル化し、これを準正規表現に基づく表記知識によて解析を行い、文字列を確定する。 - 特許庁