1.College of Physics and Information Engineering，Fuzhou University，Fuzhou 350116，China； 2.Fujian Science & Technology Innovation Laboratory for Optoelectronic Information of China，Fuzhou 350116，China； 3.School of Advanced Manufacturing，Fuzhou University，Quanzhou 362200，China
Abstract： Due to the limitations of display technology, electrowetting displays have the problems of image distortion and loss of edge details. In order to improve the display quality, this paper proposes an improved unsharp masking(UM) image adaptive enhancement algorithm based on electrowetting electronic paper. Firstly, salient images are obtained by guided filtering based on local standard deviation. Then, the dull and blurred image is obtained through the saliency map and improved guided filtering, which effectively eliminates the halo phenomenon generated after smoothing the image. Finally, the difference between the original image and the blurred image is used to extract the details of the image,and the improved unsharp masking algorithm is used to adaptively merge the details with the original image. The experimental results show that compared with the traditional linear unsharp mask method, the image evaluation index H value and PSNR value of this method are increased by 0.2% and 28.4% on average, the AMBE value is reduced by 88.4% on average, and the SSIM value is closer to 1. Therefore, this algorithm makes the detail of the image displayed on the electrowetting display more clearly, avoids the excessive enhancement of the image, and achieves a better display effect.
Key words : electrowetting display；unsharp mask；salient image；guided filtering；adaptive