关键词: 半色调, 误差扩散, 边缘检测, 可变系数

Abstract:

The error diffusion algorithm is widely used in many binary output devices, however, the worm artifacts and edge blur often appear in the halftone image generated by the traditional error diffusion algorithm. In order to overcome the above drawbacks of the algorithm, this paper proposes a new variablecoefficient error diffusion method based on image edge detection. The proposed method is based on the wellknown Ostromoukhov algorithm which can overcome the worm artifacts by the optimized filter coefficients. In addition, the image edge is detected by the Sobel operator and the error diffusion filter coefficients are adjusted according to the edge direction for keeping the image edge. The experimental results show that the halftone images generated by the proposed method have an ideal blue noise spectrum, as well as the clear edge structures.

Key words: halftone;error diffusion;edge detection;variable coefficient