Three-Dimensional Adaptive Digital Halftoning

Abstract

The automatic color equalization (ACE) algorithm, part of the Retinex-derived family of spatial color algorithms (SCAs), is an image enhancement algorithm that mimics the adjustment behavior of the human visual system (HVS). It is commonly used on a unique channel for black & white images or independently on the three channels for color images. In this work, we introduce a novel application of ACE on hyperspectral images, referred to as HyperspectrACE. Here the goal is not to introduce the most performing hyperspectral image enhancer in the field, but to discuss the performance of a qualitative model of human color sensation when applied on more than the standard RGB channels. For this reason, we present the test of the proposed approach compared with classic ACE and other classic methods, to assess the differences in image dynamic stretching and global and local filtering contrast adjustment.

Multi-layer Halftoning for Poly-jet 3D Printing

“…We use the 3D Iterative Method Controlling the Dot Placement (IMCDP) halftoning algorithm [7] to halftone patches and determine the dot placement using white and black inks to obtain the desired gray levels. Simulations have shown that the 3D IMCDP halftoning algorithm generates high-quality reproduction for all gray tones [7]- [9], however, the method has not been employed in a real 3D printing pipeline and this work is the first effort that applies 3D IMCDP to 3D printing experiments.…”