结合视觉感知特性的梯度域图像增强方法  

Perception-Based Gradient Domain Enhancement of Images

作　　者：许欣[1] 陈强[1] 孙怀江[1] 夏德深[1] 

机构地区：[1]南京理工大学计算机科学与技术学院,南京210094

出　　处：《计算机辅助设计与图形学学报》2009年第1期130-135,共6页Journal of Computer-Aided Design & Computer Graphics

基　　金：国家自然科学基金(60773172);江苏省博士后基金(AB41158)

摘　　要：常见的图像对比度增强方法在压缩图像整体动态范围的同时可有效地增强图像较暗处的细节,但图像中原较亮部分的细节往往得不到增强,甚至被削弱.针对人类视觉感知的特性提出了相对梯度的概念,首先在梯度域对图像原较亮处的梯度进行更大的拉伸,然后在最小二乘意义下重建出增强后的结果图像.通过将RGB图像变换到HSV彩色空间,将增强方法推广到彩色图像的处理中.实验结果表明,采用文中方法可有效地压缩图像的整体动态范围,同时原图像中较暗和较亮处的细节都得到了有效增强或保持.Common contrast enhancement methods compress the dynamic range of images while increasing contrast and enhancing fine details in the darker regions. In the mean time, details in the brighter regions are usually not enhanced, or even attenuated in some cases. The novelty of our method is to take the human visual perception sensitivity into consideration. We introduce the idea of relative gradients and propose a method that tends to magnify gradient more in brighter regions, and an enhanced image is reconstructed from the gradient field in least mean square sense. By transforming the RGB images to HSV space, the method is extended to the color image enhancement. Experimental results demonstrate that, by our method, details in both brighter and darker regions of the original images are enhanced or preserved.

关 键 词：对比度 图像增强 视觉感知 梯度域 

分 类 号：TP391.41[自动化与计算机技术—计算机应用技术]