Abstract: The traditional error diffusion algorithm may cause unexpected artifacts to produce and it can't present the details very well.In order to solve these problems,an error diffusion algorithm with variable coefficients is proposed on the basis of texture structure and tone awareness.In the algorithm,first,according to local visual errors of an image,the threshold is modified by performing the noise modulation in smooth regions and by utilizing the texture information in textured regions.Then,by taking into consideration the spectral characteristic of blue noise and the spatial characteristic of the image,the adaptive error diffusion coefficients at each gray level are obtained by using the ant colony algorithm.Experimental results show that the proposed algorithm can output halftone images to reduce the unexpected artifacts and can ensure the details of texture structure,and that it has a better performance in terms of PSNR and MSSIM.

Key words: error diffusion, image texture, noise modulation, ant colony optimization