一种抖动与孤立像素点分离相结合的灰度级增强方法

为了使由等离子体显示器(PDP)反γ校正和有限灰度级显示方法引起的灰度损失得到改善,在分析灰度损失原因及有序抖动和随机抖动特点的基础上,提出了一种抖动与孤立像素点分离相结合的灰度级增强方法。该方法首先采用有序抖动和孤立像素点分离对γ校正后的图像进行灰度增强;然后把图像数据映射到有限灰度级,计算有限灰度级与需要显示的灰度级之间的误差;最后采用随机抖动和孤立像素点分离对有限灰度级图像进行灰度增强。实验结果表明,反γ校正和有限灰度级图像的灰度均得到了显著增强,低灰度级和中高灰度级过渡平滑,没有周期性抖动噪声,孤立像素点的亮度显著降低,图像显示效果明显优于仅采用随机抖动或有序抖动的图像。

Dithers combined with minor pixel separation for gray-scale enhancement

In order to improve the gray-scale loss caused by anti-γ correction and limited gray-scale method,dithers combined with minor pixel separation(MPS) are proposed after analyzing the principle of gray-scale loss in plasma display panel(PDP) and characteristics of order and random dither.In the method,first,order dither combined with MPS is used to enhance image after anti-γ correction.Then image data is mapped to limited gray-scales and relative error is computed between limited gray-scales and gray-scale needed to be displayed.Finally,image processed by limited gray-scales is enhanced by random dither combined with MPS.The experiment results show that the images processed by anti-γ correction and limited gray-scale are all greatly enhanced.The gray-scale displayed in low and mid-high gray-scale region are all smooth.There is not periodic dither noise,and intensity of minor pixel is reduced significantly.The displayed image is better than it processed only by using random or order dither.