Confined Error Diffusion Algorithms for Display Device

Until now, the structural pattern at the specific gray level or at the special condition of image data was mainly issued in dithering or error diffusion method. This problem was more critical in flat panel display because of the heavy intensity of unit luminance. One of the authors published a concept, "confining error-carry within the dither mask" as a patent, but we have not published about the technology in detail as a paper. Based on the concept, in this paper, at first, we propose an algorithm named "confined error diffusion (CED)" which has the well organized architecture between random error diffusion and ordered dither method to improve the image quality and gray level expression for the flat panel display. Then, we propose an advanced CED algorithm to improve the problem of the CED related to the gradation. This algorithm can be adapted to flat panel display.

1 Introduction

Recently, many digital display devices have been introduced in the display market like Plasma Display Panel (PDP), LCD, etc. The image quality is more and more issued in product marketing for TV, Monitor. There are many factors for the image quality, halftone method, gray linearity, contrast ratio, color, sharpness, etc. Many digital halftone algorithms have been proposed such as Refs.[1]–[5]. The mainstream of the recent halftone method is the ordered dither and the error diffusion algorithm. But these algorithms were focused on the digital printing not on the display devices. In this paper, we propose a well organized halftone algorithm for flat panel display. This algorithm can be implemented in real time process and provide the high quality image.