基于小波和Otsu法的二维条码图像二值化

针对光照不均或背景十分复杂的情况下，全局阈值法无法正确对二维条码图像进行二值化而局部阈值法又会出现块效应的问题，提出一种基于小波分解和大津法的条码图像二值化方法。利用小波分解获得物体表面光照的近似分布进而消除光照不均的影响，并用大津法对获得的图像二值化。该方法既可以消除光照不均的影响，又可以通过选择合适的小波函数使得物体表面光照的近似分布尽量平滑，避免了局部阈值法出现的块效应。

2D Barcode Image Binarization Based on Wavelet and Otsu Method

In the situation of unbalancing illumination or too complex background, global threshold can not binarize the 2D barcode image correctly, and local threshold can cause the block effect. In order to resolve this problem, a binarization method based on wavelet analysis and the Otsu method is proposed. This method estimates the approximate illumination distribution using wavelet analysis, and eliminates the effect of unbalancing illumination with the acquired illumination distribution. After that, the method binarizes the processed image using the Otsu method. This method not only eliminates the effect of unbalancing illumination, but also avoids the block effect encountered in local threshold method, by selecting appropriate wavelet function to make the approximate illumination distribution smooth.