<title>Time varying halftoning</title>

Abstract

For displays with limited color capability, color halftoning is often used to induce the illusion of more color levels than the device can truly render. In such cases, the pattern created by the halftone technique can be visible due to the limited geometrical resolution of the display device. Unlike printing, the halftone pixels of the display devices are still visible and the patterns created on display devices can be easily detected. When animated images are played and the frame rates are played in a mode that uses a limited number of colors and halftoning techniques, the patterns are very visible because they are perceived as a reference system fix to the playing window, while the image content is moving. In this paper we propose a halftone technique that varies the halftone pattern in time such that the pattern visibility is reduced. This conducts to a higher quality of the displayed image, especially noticeable for dynamic images. The technique enables the use of display devices (or displaying modes) with limited color capability for higher quality images.