整合影像半色調亮度補償之電子紙影像處理工具

Abstract

電泳式顯示器已經成為消費型電子紙主要的解決方案，但是電泳式顯示器在驅動上也有一些先天的限制。首先電泳式顯示器的光電響應曲線呈現非線性的，其次是電泳式顯示器對於溫度相當敏感，此外可以呈現輸出的影像灰階數相當有限。影像不經過增加可用灰階數或影像預處理直接透過面板顯示，所得到影像品質不盡理想。

在本論文中，我們提出一個綜合性的影像工具，它可自動估算在不同環境溫度的光學反射函數，執行適應性半色調影像處理，以改善視覺品過面板顯示品質。校正電泳式顯示器非線性響應並且補償。我們所提出的方法已經通過實際電泳式顯示器系統驗證，得到相當不錯的成果。The electrophoretic display (EPD) has become the main solution to electronic papers, but there are several limitations when it is being driven. First of all, the optical response curve of the EPD is nonlinear and temperature sensitive. In addition, the number of gray levels that can be displayed is also quite limited. The image quality is unsatisfactory if the images shown on the panel are not preprocessed to increase the number of visual gray levels and compensate the characteristics of the EPD. In this paper, we present an integrated image tool to automatically estimate the reflectance function curves under different ambient temperatures, perform adaptive image halftoning to improve visual quality, and calibrate the image to compensate the nonlinear response of EPD. The proposed approach has been verified on practical EPD panels and promising results have been achieved.