一种基于POCS的用于恢复半色调颜色量化图像的恢复算法。

A POCS-based restoration algorithm for restoring halftoned color-quantized images.

作者信息

Fung Yik-Hing, Chan Yuk-Hee

机构信息

Centre for Multimedia Signal Processing, Department of Electronic and Information Engineering, The Hong Kong Polytechnic University, Kowloon, China.

出版信息

IEEE Trans Image Process. 2006 Jul;15(7):1985-92. doi: 10.1109/tip.2006.873432.

DOI:10.1109/tip.2006.873432

PMID:16830918

Abstract

This paper studies the restoration of images which are color-quantized with error diffusion. Though there are many reported algorithms proposed for restoring noisy blurred color images and inverse halftoning, restoration of color-quantized images is rarely addressed in the literature especially when the images are color-quantized with halftoning. Direct application of existing restoration techniques are generally inadequate to deal with this problem. In this paper, a restoration algorithm based on projection onto convex sets is proposed. This algorithm makes use of the available color palette and the mechanism of a halftoning process to derive useful a priori information for restoration. Simulation results showed that it could improve the quality of a halftoned color-quantized image remarkably in terms of both SNR and CIELAB color difference metric.

摘要

本文研究了经误差扩散进行颜色量化的图像的恢复问题。尽管已有许多针对恢复噪声模糊彩色图像和逆半色调处理提出的算法，但文献中很少涉及经颜色量化的图像的恢复，特别是当图像是通过半色调进行颜色量化时。直接应用现有的恢复技术通常不足以解决这个问题。本文提出了一种基于凸集投影的恢复算法。该算法利用可用的调色板和半色调处理机制来推导用于恢复的有用先验信息。仿真结果表明，在信噪比和CIELAB色差度量方面，它都能显著提高经半色调处理的颜色量化图像的质量。