Recognition method for hand drawn electronic symbols based on structural relationship between primitives
CHEN Xiao jie1, FANG Gui sheng2
(1.School of Mechanical Engineering, Zhejiang University, Hangzhou 310027, China;2.School of Mechanical 
and Automotive Engineering, Zhejiang University of Water Resources and Electric Power, Hangzhou 310018, China)

Abstract: Aimirg at the problem of difficult to recognize and understand the hand drawn symbols, because of irregular and fuzzy, the features of hand drawn electrical symbols, stroke segmentation of the symbols, the identification of the primitive type, structural relations between primitives, the types of the similarity between symbols and other aspects were studied, and a new recognition method for hand drawn electrical symbols based on structural relationship between primitives was proposed. First of all, hand drawn electrical symbols were segmented into several primitives based on their characteristics. Then attributed relational graph was used to describe the attribution of the primitives and the structural relationship between primitives in hand drawn electrical symbols. And a method for calculating the similarity of hand drawn electrical symbols matching based on attributed relational graph was proposed. Finally, through calculating the similarity between the unknown symbol and the symbol in template library, the unknown hand drawn electrical symbol was recognized successfully. The results indicate that the proposed method can be used to construct an effective, trainable, multiline character recognizer, which is not affected by the direction, the size and the drawing order of the symbol.

Key words: hand drawn electrical symbols recognition; primitive; stroke segmentation; attributed relational graph