工业字符识别中实用的预处理技术

Practical Pretreatment Technology in Industry Character Recognition

为了提高工业字符的识别率,提出了一种快速而实用的预处理技术。结合掩模边界、仿射变换和线性插值对用户选择区域内的字符进行旋转校正;利用投影方法对字符进行分行,为克服点阵字体误分行的情况,提出了波形膨胀的方法;针对黏连字符的情况,根据预定义字符宽度,确定黏连字符个数,并求取预分割范围,再利用投影方法求取最佳分割位置。实际测试表明,经过该方法处理后的字符,能达到99%以上的识别率。目前该方法已经应用到嵌入式机器视觉工业现场。

The paper proposes a practical preprocessing technology to improve the recognition rate of the industry characters.The revolving adjustment is made to the data of ROI,combining the mask boundary,the affine transformation and the linear interpolation.The paper also carrys on the branch using the projection method to the character and propose the wave expansion method to overcome the situation of the branch bitmap fonts error.According to the pre-definition character width,the number of the adhesion characters is determuned.Besides,the pre-division scope and the best division position using projection method are found out.The actual test is made to prove that： the recognition rate of the characters can achieve 99% after this method processing.This method has been applied in the embedded machine vision industrial field.