Online hand-written chemical symbol identification method based on Hidden Markov model

Abstract

An online hand-written chemical symbol identification method based on the Hidden Markov model solves the problem of the online identification of chemical symbol written by any one writer on any one device. The method constructs a processing framework of identification of the online written chemical symbol, and employs a hierachical processing and step-by-step optimization strategy. The method based on a support vector machine selects grid features and peripheral contour features to distinguish organic ring symbols and non-ring symbols, and the classification error rate is controlled under 0.2%. The method based on the Hidden Markov model to identify concrete symbols, and the accuracy is more than 90%. In order to improve the precision design, a set of preprocessing flow is designed, and the post-processing measures such as candidate result reliability, chemical symbol adjacent matrixes and the atom element conservation detection are employed. The method has the universal meaning, systematicness and completeness through the experimental proof of the data source such as the input of a Tablet PC, a digital panel and a mouse simulation pen, and can be used for the online hand-written chemical symbol identification field.

Description

[0001] 【Technical field】 [0002] The invention belongs to the field of pattern recognition and human-computer interaction, and in particular relates to an online handwritten chemical symbol recognition method based on a hidden Markov model. [0003] 【Background technique】 [0004] A chemical formula (chemical equation) is a formula that expresses the law of a chemical reaction, and is the most important form of expression of chemistry and chemical activities. A chemical formula, like a mathematical formula, is a very widely used expression in the field of natural science. With the development of information society, more and more chemistry-related work is transferred to electronic equipment. However, how to quickly and efficiently enter chemical knowledge, especially chemical formulas, into the computer is still a difficult problem. At present, chemical formulas are mainly entered by professional software. The common disadvantages of this type of software include complex int...

AI Technical Summary

Problems solved by technology

The difficulties in conducting related research include: (1) the set of chemical symbols is relatively large, and there are many similar structures in it; (2) the size and position of the symbols imply certain chemical meanings, which need to be analyzed and transmitted after the symbols are recognized. Concealed information; (3) The handwritten sample is seriously deformed and the stroke quality is uneven

Therefore, accurate recognition of handwritten chemical symbols is a challenging task

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