工程科学学报，第39卷，第12期：1888-1897,2017年12月 Chinese Journal of Engineering,Vol.39,No.12:1888-1897,December 2017 D0l:10.13374/j.issn2095-9389.2017.12.016:http://journals..ustb.edu.cn 一种提高图像对比度和视觉质量的新型区域背光算法 张涛”，巫红英区，李蒙》，雷志春13》 1)天津大学电气自动化与信息工程学院，天津3000722)深圳华为技术有限公司，深圳5181293)鲁尔西应用科学大学传感与测量研究 所，北莱菌威斯特法伦州45479 ☒通信作者，E-mail:wuhongying@(u.cdu.cm 摘要为尽可能高地提高液晶显示器(LCD)的动态范围以实现高动态范围显示，提出了一种基于动态阈值背光亮度提取 和液晶像素补偿两步法的区域背光算法，以提高液晶显示器背光模组和液晶面板的动态范围，从而使调光后图像的对比度和 视觉质量都得到增强.仿真结果表明，用该算法区域调光后图像的对比度平均提高了113.60%.此外，用自主研发的直下式 白光LED分区背光液晶显示样机通过显示具体图像对所提出算法进行性能测试，显示结果表明区域调光后图像的层次和色 彩得到了增强且提高了对比度，证明了所提出算法能有效提高液晶显示器的对比度并改善显示画质. 关键词高动态范围：区域背光：背光亮度：像素补偿：对比度 分类号TN27:TN873 A novel local dimming algorithm to improve image contrast and visual quality ZHANG Tao,WU Hong-ying,LI Meng,LEI Zhi-chun' 1)School of Electrical Automation and Information Engineering,Tianjin University,Tianjin 300072,China 2)Shenzhen Huawei Technology Co.,Ltd.,Shenzhen 518129,China 3)Institute of Sensing and Measurement,University of Applied Sciences Ruhr West,North Rhine-Westphalia 45479,Germany Corresponding author,E-mail:wuhongying@tju.edu.cn ABSTRACT With the emergence of high dynamic range (HDR)images and videos,improving the liquid crystal display (LCD) technology has become an urgent requirement.The development of HDR display systems is becoming the focus of research in the dis- play technology.To improve the dynamic range of LCDs to the best possible extent,a local dimming algorithm based on dynamic- threshold backlight luminance extraction and two-step liquid crystal pixel compensation was proposed to improve the dynamic range of a backlight model and an LCD panel,thereby enhancing the contrast and visual quality of the dimmed image.The experimental results demonstrate that the proposed algorithm can improve the image contrast ratio by approximately 113.60%on average.Additionally,on the direct white light-emitting diode backlight LCD,specific images were used to verify the accuracy of the proposed algorithm.The display effects indicate that the layering and color of dimmed images are enhanced and the image contrast ratio is improved.Based on these results,it can be concluded that the proposed algorithm can effectively improve both the contrast of LCDs and the display quality. KEY WORDS high dynamic range:local dimming:backlight luminance;pixel compensation;contrast ratio 动态范围广义上是指某一变化事物可以改变的跨 就越强.自然界大约有8个数量级的亮度范围，从星 度范围.对于静态图像或视频帧，动态范围为最暗色 空下的夜景（亮度约为103cd)至太阳本身亮度（约为 调到最亮色调的范围，光线的明暗变化在这个范围内 105cd).人眼由于其自动调节机制，可以捕捉到5个 实现。范围越大，变化层次越多，对细节的描述能力也 数量级的亮度范围，但现行的低动态范围(low dynamic 收稿日期：2017-03-06 基金项目：天津市科技计划资助项目(16 YFZCGX00760):图像视频HDR显示研究资助项目(2016120024000202)工程科学学报，第 39 卷，第 12 期: 1888--1897，2017 年 12 月 Chinese Journal of Engineering，Vol． 39，No． 12: 1888--1897，December 2017 DOI: 10． 13374 /j． issn2095--9389． 2017． 12． 016; http: / /journals． ustb． edu． cn 一种提高图像对比度和视觉质量的新型区域背光算法 张 涛1) ，巫红英1) ，李 蒙2) ，雷志春1，3) 1) 天津大学电气自动化与信息工程学院，天津 300072 2) 深圳华为技术有限公司，深圳 518129 3) 鲁尔西应用科学大学传感与测量研究 所，北莱菌威斯特法伦州 45479 通信作者，E-mail: wuhongying@ tju． edu． cn 摘 要 为尽可能高地提高液晶显示器( LCD) 的动态范围以实现高动态范围显示，提出了一种基于动态阈值背光亮度提取 和液晶像素补偿两步法的区域背光算法，以提高液晶显示器背光模组和液晶面板的动态范围，从而使调光后图像的对比度和 视觉质量都得到增强． 仿真结果表明，用该算法区域调光后图像的对比度平均提高了 113. 60% ． 此外，用自主研发的直下式 白光 LED 分区背光液晶显示样机通过显示具体图像对所提出算法进行性能测试，显示结果表明区域调光后图像的层次和色 彩得到了增强且提高了对比度，证明了所提出算法能有效提高液晶显示器的对比度并改善显示画质． 关键词 高动态范围; 区域背光; 背光亮度; 像素补偿; 对比度 分类号 TN27; TN873 A novel local dimming algorithm to improve image contrast and visual quality ZHANG Tao1) ，WU Hong-ying1)  ，LI Meng2) ，LEI Zhi-chun1，3) 1) School of Electrical Automation and Information Engineering，Tianjin University，Tianjin 300072，China 2) Shenzhen Huawei Technology Co． ，Ltd． ，Shenzhen 518129，China 3) Institute of Sensing and Measurement，University of Applied Sciences Ｒuhr West，North Ｒhine-Westphalia 45479，Germany Corresponding author，E-mail: wuhongying@ tju． edu． cn ABSTＲACT With the emergence of high dynamic range ( HDＲ) images and videos，improving the liquid crystal display ( LCD) technology has become an urgent requirement． The development of HDＲ display systems is becoming the focus of research in the dis￾play technology． To improve the dynamic range of LCDs to the best possible extent，a local dimming algorithm based on dynamic￾threshold backlight luminance extraction and two-step liquid crystal pixel compensation was proposed to improve the dynamic range of a backlight model and an LCD panel，thereby enhancing the contrast and visual quality of the dimmed image． The experimental results demonstrate that the proposed algorithm can improve the image contrast ratio by approximately 113. 60% on average． Additionally，on the direct white light-emitting diode backlight LCD，specific images were used to verify the accuracy of the proposed algorithm． The display effects indicate that the layering and color of dimmed images are enhanced and the image contrast ratio is improved． Based on these results，it can be concluded that the proposed algorithm can effectively improve both the contrast of LCDs and the display quality． KEY WOＲDS high dynamic range; local dimming; backlight luminance; pixel compensation; contrast ratio 收稿日期: 2017--03--06 基金项目: 天津市科技计划资助项目( 16YFZCGX00760) ; 图像视频 HDＲ 显示研究资助项目( 2016120024000202) 动态范围广义上是指某一变化事物可以改变的跨 度范围． 对于静态图像或视频帧，动态范围为最暗色 调到最亮色调的范围，光线的明暗变化在这个范围内 实现． 范围越大，变化层次越多，对细节的描述能力也 就越强． 自然界大约有 8 个数量级的亮度范围，从星 空下的夜景( 亮度约为 10 － 3 cd) 至太阳本身亮度( 约为 105 cd) ． 人眼由于其自动调节机制，可以捕捉到 5 个 数量级的亮度范围，但现行的低动态范围( low dynamic