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Proceedings Paper

Memory efficient hierarchical error diffusion
Author(s): Zhen He; Zhigang Fan
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Paper Abstract

Hierarchical Error Diffusion (HED) developed in [14] yields high-quality color halftone by explicitly designing three critical factors: dot overlapping, positioning, and coloring. However, HED requires more error memory buffer than the conventional error diffusion algorithms since the pixel error is diffused in dot-color domain, instead of colorant domain. This can potentially be an issue for certain low-cost hardware implementation. This paper develops a memory-efficient HED algorithm (MEHED). To achieve this goal, the pixel error in dot-color domain is converted backward and diffused to future pixels in input colorant domain, say, CMYK for print applications. Since the error-augmented pixel value is no longer bounded within the range [0, 1.0], the dot overlapping control algorithm developed in [14] needs to be generalized to coherently handle the pixel density of outside the normal range. The key is to carefully split the modified pixel density into three parts: negative, regular, and surplus densities. The determination of regular and surplus densities needs to be dependent on the density of K channel, in order to maintain local color and avoid halftone texture artifact. The resulting dot-color densities are serves as the input to hierarchical thresholding and coloring steps to generate final halftone output. Experimental results demonstrate that MEHED achieves similar image quality compared to HED.

Paper Details

Date Published: 19 January 2010
PDF: 10 pages
Proc. SPIE 7528, Color Imaging XV: Displaying, Processing, Hardcopy, and Applications, 75280X (19 January 2010); doi: 10.1117/12.836032
Show Author Affiliations
Zhen He, Xerox Corp. (United States)
Zhigang Fan, Xerox Corp. (United States)


Published in SPIE Proceedings Vol. 7528:
Color Imaging XV: Displaying, Processing, Hardcopy, and Applications
Reiner Eschbach; Gabriel G. Marcu; Shoji Tominaga; Alessandro Rizzi, Editor(s)

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