自适应反馈视觉感知差的误差扩散半色调算法

文章基于人眼对亮度的视觉感受特性。提出了一种自适应反馈视觉感知差的误差扩散算法（PEF Error Diffusion算法）。首先提出视觉感知差的概念，然后根据原图像区域的灰度特征，自适应地计算反馈系数，将视觉感知差反馈给原连续调图像，以补偿误差扩散所引起的不同区域的灰度损失。实验结果表明，由于视觉感知差的引入及反馈系数的自适应变化。PEF Error Diffusion算法能够明显增强图像的整体对比度．减弱点增益现象的不良影响，并准确再现更多的图像细节．因而表现出比传统算法更好的主观视觉效果。

Adaptive Error Diffusion with Perceived Error Feedback

This paper presents an adaptive error diffusion halftoning with perceived error feedback, named PEF Error Diffusion. It is based on human visual perception of brightness. First we define a perceived error between the continuous-tone image and a traditional halftone image as well as an adaptive feedback coefficient. Then the continuous-tone image is adjusted adaptively by the feedback of perceived error. Due to the perceived error and the adaptive coefficient involved, PEF Error Diffusion greatly enhances the overall contrast, efficiently weakens the dot-overgain and gives more details, especially in the darker area. The result shows that it does display better visual quality than traditional error diffusion.