计算机工程与应用 ›› 2011, Vol. 47 ›› Issue (9): 196-199.

• 图形、图像、模式识别 • 上一篇    下一篇

非均匀光照图像的子块部分重叠对数变换

焦立男1,孙朝云1,沙爱民2   

  1. 1.长安大学 信息工程学院 电子信息工程系,西安 710064
    2.长安大学 公路学院,西安 710064
  • 收稿日期:1900-01-01 修回日期:1900-01-01 出版日期:2011-03-21 发布日期:2011-03-21

Partially overlapped sub-block logarithmic transformation of images under non-uniform illumination

JIAO Linan1,SUN Zhaoyun1,SHA Aimin2   

  1. 1.Department of Electronic & Information Engineering,College of Information Engineering,Chang’an University,Xi’an 710064,China
    2.College of Highway,Chang’an University,Xi’an 710064,China
  • Received:1900-01-01 Revised:1900-01-01 Online:2011-03-21 Published:2011-03-21

摘要: 在非均匀光照下获得的图像往往具有高动态范围。大多数现有的全局对比度增强算法对此种图像效果并不好。一种简化的对数变换公式被提出来解决这一问题,更进一步子块部分重叠方法也被采纳进来实现局部的对比度增强。为了达到优化的目的,两种对比度测度用来寻找优化的变换参数。这些方法合并成一种新的算法POSLT(子块部分重叠的对数变换)。POSLT尽管计算复杂性比较高,但是展示出了良好的性能和可控性。实验结果也显示出了该算法在对比度增强中的局部适应性,有力支持了POSLT。

关键词: 对比度增强, 高动态范围图像, 对数变换, 对比度测度, 子块

Abstract: Most existing global contrast enhancement algorithms can not deal with high dynamic range images which are often under non-uniform illumination.Thus a simplified logarithmic transformation equation has been proposed to meet this demand.Furthermore a partially overlapped sub-block method is also adopted to perform local contrast enhancement.For purpose of optimization,two contrast measures are used for finding optimal transformation parameters.They merge into a new algorithm,called POSLT(Partially Overlapped Sub-block Logarithmic Transformation).POSLT exhibits good performance and controllability even if it has high computational complexity.Experimental results show its local adaptation for contrast enhancement and give firmly support to POSLT.

Key words: contrast enhancement, high dynamic range image, logarithmic transformation, contrast measure, sub-block