Multilevel halftone screen design: Keeping texture or keeping smoothness?

Multilevel halftoning algorithms are becoming increasingly important as the capabilities of image output devices improve. The traditional approach to multilevel halftoning is hampered by the appearance of contouring in the vicinity of native tones of the output device. To overcome this limitation, we propose a novel framework based on maintaining a consistent periodic, clustered-dot halftone texture across the tone scale. We develop metrics for granularity and structure dissimilarity, and show how these can be used to guide the manner in which the halftone texture evolves from native tone to native tone, across the tone scale. Experimental results confirm the benefits of our new approach.