信息填涂卡文档图像预处理算法的研究

Pre-processing algorithm for document image of information card

阐述了信息填涂卡文档图像标记识别系统中的预处理算法 .对信息填涂卡文档图像预处理中的图像二值化、图像偏斜纠正以及图像平滑等关键步骤进行了描述 .在图像二值化过程中采用全局阈值法 ,在图像偏斜纠正过程中给出了一种基于Wingner Ville分布和水平投影直方图的偏斜纠正算法 ,在图像平滑过程中采用特定的同步孔平滑算法 .

This paper discussed a series of pre-processing theory and an algorithm for analyzing document image of information card based on optical mark recognition. Image binarizing, skew angle correction of image and image smoothing in pre-processing were described. Global threshold method was applied to image binarizing. An algorithm based on Wingner-Ville Distribution and Horizontal histogram was presented in skew angle correction of image. The proposed algorithm of special synchronous region smoothing was applied to image smoothing. The result showed that these methods could meet the need of pre-processing document image.