Image Understanding System for Printed Chemical Structures
印刷された化学構造式の認識理解システム

Naoki Itoh, Takashi Nakayama
1995 Proceedings of Annual Conference Japan Society of Information and Knowledge  
This paper describes an image understanding system which reads printed chemical structures via an image scanner , recognizes them a£ chemical structures and gives 宅 he result in the f( ) rm of connection tables . The system accepts chemical stmcture diagrams 韮 ncluding characters and stereochemical symbols depicted in ordinary textbooks and articles . The recognition and unde 【stand 量 ng process of image data comprises the following three major steps : at first , the basic recognition of bui!
more » ... ng blocks of inpllt data a5 figure primitives, then the graph gene 匸ation from the result of the previous process, and the interpretation and understanding of the graph as a chemical g :aph ( a chemical structure ) . In other words , the whole process consists of hierarChically distributed 魚 nctions , where the bottom layer is the first one , and the top the last . The process normally pmgresses from the bottom to the top . HQwever , the system works cooperatively between the layers when so 皿 e layer suspends judgements or detects the possibility of misjudgements . For instance , an assumed character area could be ambiguouS when the cha 職 cter is overlapped with other figure elements ; crossing iines may be interpreted as a cross of two single lines , or four lines connected to a single node . These undetermined situations can be resolved with cooperative processing of two or more layer functions using domain know 玉 edge concerning chemical structures . Experiments have proved that the system is powerful enough to give suMcient precision in terms of center − line extraction of comp 置 ex chemical structures which a co 皿 皿 ercial product cannot recognize precisely .
doi:10.2964/jsikproc.3.0_61 fatcat:jhvxigisdnajbkqqifyxjxwsxu