Priority-Based Stippling and Its Stylization Applications



This paper presents a new and efficient automatic method for structure-preserving stippling. The core idea is to concentrate on structure preservation by using a priority-based scheme that treats extremal pixels first and preferentially assigns positive error to lighter pixels and negative error to darker pixels, emphasizing contrast. The use of a nonlinear spatial function to shrink or exaggerate errors implicitly provides global adjustment of density. Our adjustment respects contrast and hence allows us to preserve structure even with few stipples. Beyond the advantage of good structure preservation, our algorithm provides many variations to extend our stippling to other artistic styles. In addition, we demonstrate that variations on our priority-based scheme by a multiple-stage process can provide flexibility to promote different kinds of interesting features. We explore a variety of stylized effects, including heightening, scratchboard, and line drawing, all within the unifying framework of stippling.

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