Abstract:

Hmong characters in Xiangxi is used in the Hmong area of Xiangxi.But there is  still a research gap for its machine identification.The pretreatment of Hmong character images is a prerequisite for the identification and it will directly influence the effect of image characteristic extraction and identification.The pretreatment proposed involves graying of character images through weighted average method,binarization through Ostu algorithm,and image smoothing and uniformization based on the combination of Homomorphic and the improved median filtering.This pretreatment constitutes the basis for the image identification of Hmong characters in Xiangxi.

Key words: Hmong characters in Xiangxi；pretreatment, graying, binarization, image smoothing, uniformization