Polyomino-Based Digital Halftoning

TL;DR

This paper introduces a novel polyomino-based threshold structure for digital halftoning that enhances visual quality and spectral properties, outperforming existing threshold matrix methods.

Contribution

It proposes a new non-periodic, hierarchical polyomino-based approach for generating threshold structures used in halftoning algorithms, with demonstrated superior performance.

Findings

Achieves blue-noise spectral properties in halftoning.

Produces high-quality halftone images.

Outperforms state-of-the-art threshold matrix methods.

Abstract

In this work, we present a new method for generating a threshold structure. This kind of structure can be advantageously used in various halftoning algorithms such as clustered-dot or dispersed-dot dithering, error diffusion with threshold modulation, etc. The proposed method is based on rectifiable polyominoes -- a non-periodic hierarchical structure, which tiles the Euclidean plane with no gaps. Each polyomino contains a fixed number of discrete threshold values. Thanks to its inherent non-periodic nature combined with off-line optimization of threshold values, our polyomino-based threshold structure shows blue-noise spectral properties. The halftone images produced with this threshold structure have high visual quality. Although the proposed method is general, and can be applied on any polyomino tiling, we consider one particular case: tiling with G-hexominoes. We compare our polyomino-based threshold structure with the best known state-of-the-art methods for generation threshold matrices, and conclude considerable improvement achieved with our method.