Image quality improvement for electrophoretic displays by combining contrast enhancement and halftoning techniques

The electrophoretic display (EPD) has dominated the panel used in electronic readers. However, getting more than 16 observable gray levels on an EPD is still a big challenge. A true color image should be converted into a 16 gray level image for displaying it on an EPD. In this paper, we propose an image processing tool that combines contrast enhancement and the modified Nasik pattern halftoning to deal with the problems in the image conversion chain. The experimental results show that the processed image has preserved more image textures after the image data are quantized into 16 gray levels1.