Photometric calibration for image enhancement of electrophoretic displays

The electrophoretic display (EPD) has become the main solution to electronic paper, but it is temperature sensitive with only a few number of gray levels. In this paper, we present an integrated image tool to automatically estimate the reflectance function curves under different 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 a practical EPD panel and promising results are achieved.