Visual Contrast Enhancement Algorithm Based on Histogram Equalization

Sensors

Chih-Chung Ting²  Bing-Fei Wu³  Meng-Liang Chung³  Chung-Cheng Chiu¹  Ya-Ching Wu¹ 

[1] Department of Electrical and Electronic Engineering, Chung Cheng Institute of Technology, National Defense University, Taoyuan 33551, Taiwan; E-Mails:;School of Defense Science, Chung Cheng Institute of Technology, National Defense University, Taoyuan 33551, Taiwan; E-Mail:;Institute of Electrical and Control Engineering, National Chiao Tung University, Hsinchu 30010, Taiwan; E-Mails:

关键词: contrast enhancement;    dynamic range;    histogram equalization (HE);    just-noticeable difference (JND);   

DOI  :  10.3390/s150716981

来源: mdpi

【 摘 要 】

Image enhancement techniques primarily improve the contrast of an image to lend it a better appearance. One of the popular enhancement methods is histogram equalization (HE) because of its simplicity and effectiveness. However, it is rarely applied to consumer electronics products because it can cause excessive contrast enhancement and feature loss problems. These problems make the images processed by HE look unnatural and introduce unwanted artifacts in them. In this study, a visual contrast enhancement algorithm (VCEA) based on HE is proposed. VCEA considers the requirements of the human visual perception in order to address the drawbacks of HE. It effectively solves the excessive contrast enhancement problem by adjusting the spaces between two adjacent gray values of the HE histogram. In addition, VCEA reduces the effects of the feature loss problem by using the obtained spaces. Furthermore, VCEA enhances the detailed textures of an image to generate an enhanced image with better visual quality. Experimental results show that images obtained by applying VCEA have higher contrast and are more suited to human visual perception than those processed by HE and other HE-based methods.

【 授权许可】

CC BY   
© 2015 by the authors; licensee MDPI, Basel, Switzerland.