Contrast Enhancement of Dithered Images Using Complex Wavelets and Novel Amplification Factors

Abstract

Dithering creates an illusion of continuous tone output for a binary device. Error diffusion-based dithering or halftoning is an efficient technique that is primarily getting used in printing. In this paper error diffusion halftoning has been used to achieve image dithering based on complex wavelets. Similar to the wavelet-based dithering, Floyd-Steinberg error diffusion has been incorporated, but in addition a new set of sub band amplification factors is coined in the proposed method to further enhance the contrast in a dithered image. Experimental results show that the proposed method is superior to state-of-the-art methods in terms of subjective and objective assessments.