Study and Development of Error Diffusion Techniques for Digital Halftoning

Abstract

In this paper different Digital halftoning techniques is implemented and studied. Digital half toning technique plays essential role in printing applications where printing devices are having bi level capabilities that is they can fire a dot or not. Since image is having more shades we require half toning to convert a gray scale image it a binary one. To do so, first AM(Amplitude Modulation) half toning and then FM (Frequency Modulation) halftoning techniques is performed such as constant thresholding, classical halftoning, error diffusion, block error diffusion and edge enhancement error diffusion and dithering with blue and green noise. For commenting on quality of halftones figures of merit has been calculated and compared.


Figures of merit are peak signal to noise ratio, weighted signal to noise ratio, linear distortion measure and universal quality index. Also radially averaged power spectrum and anisotropy two spectral characteristics of dithered has been calculated which is used for commenting on stochastic processes