电润湿电子纸显示灰度等级不足且由于油墨回流现象造成图像对比度下降而显示效果不佳。本文针对电润湿显示提出一种基于像素邻域灰度信息的误差扩散算法。首先, 通过直方图均衡处理提高图像对比度, 然后在经典误差扩散算法基础上, 根据图像当前像素邻域平均灰度, 像素与邻域平均灰度差异以及邻域灰度相似性对原固定阈值调节。实验结果表明, 直方图均衡处理加上改进后算法相较于传统误差扩散算法, 图像评价指标PSNR值、SSIM值和UIQI值分别提高了约0.3~0.5 dB, 0.03~0.04, 0.02~0.04。最终在电润湿电子纸上显示的图像质量有大部分提高, 细节层次更丰富, 且保留了图像边缘。

Electrowetting electronic paper shows insufficient gray scale and poor image contrast due to ink reflow phenomenon. In this paper, an error diffusion algorithm based on pixel neighborhood gray information was proposed for electrowetting electronic paper display. Firstly, the image contrast was improved by histogram equalization processing. Then, based on the classical error diffusion algorithm, the original fixed threshold was adjusted according to the current pixel's neighborhood average gray level, the difference and similarity between pixel and neighborhood pixel. The experimental results show that the histogram equalization process plus the improved algorithm compared with the traditional error diffusion algorithm, the PSNR, SSIM and UIQI values of image evaluation index are respectively improved by about 0.3-0.5 dB, 0.03-0.04 and 0.02-0.04. Eventually, the quality of the image displayed on the electrowetting electronic paper is mostly improved, the level of detail is richer, and the edges of the image are preserved.