基于局部特征和二维PDF修正的图像增强算法

Algorithm of Image Enhancement Based on Local Characteristics & Two-Dimensional PDF Modification

文章提出一种改进的图像增强算法,结合图像直方图和邻域窗口中局部特性,将一维PDF(概率密度函数)转化为二维,根据生成的二维PDF得到修正因子,对原始直方图的各灰度级频数进行修正,再按照修正结果对原图像进行均衡化处理,避免了过增强现象的出现,通过实验和已有算法进行了比较,证明该算法对各种图像均可取得较好的处理效果.

An improved algorithm of gray image enhancement is proposed in the paper. This algorithm turns PDF to a two-dimensional PDF based on image histogram and local characteristics. Based on the two-dimensional PDF, a modified factor can be obtained, which is used to revise and improve the fi＇equencies of all gray levers and equalize the image so as to free from over-enhancement. The experimental results have proved that the new method has a better performance on image enhancement than other methods.