Numeral Recognition Based On The Rotation Invariance

In the technique of Optical Character Recognition, when recognising the character with complicated space of a whole page, it is required that the character with big revolving angle should be recognised directly without rectification. Aim at this problem, a sort of recognising method of the printing number with revolving invariance is discussed in this paper.Firstly, the pretreatment of character to be recognized is researched, stressed discussing the subdivisional process of character, and a kind of fast shape preserving morphological thinning algorithm is used. In the following, how to construct the structure model on the basis of characteristic point) sub-stroke and their interrelation is discussed, and a kind of method that describe sub-stroke through the feature of the sequence of curvature is brought forward. Finally, the paper adopts the recognising model of printing number that base on repository, and describes the constructing method of repository.Those experiments that are made in the specimens of different revolving angles of multi-fonts' printing numbers shows that the recognising model has good effect in recognising printing number with big revolving angle. As for script number which restrict calligraph, the model also does well.