Computer Engineering and Applications ›› 2015, Vol. 51 ›› Issue (1): 167-171.

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Adaptive dynamic clipped histogram equalization title

CHEN Yongliang, WANG Huabin, TAO Liang   

  1. School of Computer, Anhui University, Hefei 230601, China
  • Online:2015-01-01 Published:2015-01-06


陈永亮,王华彬,陶  亮   

  1. 安徽大学 计算机科学与技术学院,合肥 230601

Abstract: Conventional HE may introduce some visual degradation effect while enhancing image. In order to overcome such drawback, many methods for brightness preserving and contrast enhancement have been proposed, but the methods can’t ensure the aim. This paper proposes a new method, known as Adaptive Dynamic Clipped Histogram Equalization(ADCHE). Firstly, the method smoothes the histogram and partitions the histogram. Next each partition will be assigned to a new dynamic range. And then clipping process is implemented to each sub-histogram. Finally, the conventional HE is implemented to each sub-histogram and normalize the out image to the input mean brightness. The results of the experiments show that the proposed method enhances the contrast while preserving mean brightness.

Key words: Histogram Equalization(HE), histogram segmentation, contrast enhancement, brightness preserving

摘要: 传统的直方图均衡化算法在增强图像的同时可能会引入一些视觉退化效应,如一些图像的部分区域出现过度增强。为了克服这个缺点,已有一些灰度均值保持算法,但是这些算法并不能很好地保持图像处理前后灰度均值的稳定性。提出了一种自适应动态峰值剪切直方图均衡化算法:使用滤波器对原图像的直方图进行滤波操作,并且根据图像的信息来确定分割区间及区间数目;对分割的区间进行重新映射;对区间的直方图进行剪切操作,然后分别地进行均衡化处理,并对处理后的图像进行灰度归一化操作。实验结果表明,该算法可以很好地在保持原图像均值的前提下实现图像增强。

关键词: 直方图均衡化, 直方图划分, 对比度增强, 亮度保持