Tuyển tập báo cáo các nghiên cứu khoa học quốc tế ngành hóa học dành cho các bạn yêu hóa học tham khảo đề tài: Research Article A New Inverse Halftoning Method Using Reversible Data Hiding for Halftone Images | Hindawi Publishing Corporation EURASIP Journal on Advances in Signal Processing Volume 2010 Article ID 430235 13 pages doi 2010 430235 Research Article A New Inverse Halftoning Method Using Reversible Data Hiding for Halftone Images Jia-Hong Lee 1 Mei-Yi Wu 2 and Hong-Jie Wu1 1 Department of Information Management National Kaohsiung First University of Science and Technology Kaohsiung 811 Taiwan 2 Department of Information Management Chang Jung Christian University Tainan 711 Taiwan Correspondence should be addressed to Mei-Yi Wu barbara@ Received 26 December 2009 Revised 28 July 2010 Accepted 5 October 2010 Academic Editor Alex Kot Copyright 2010 Jia-Hong Lee et al. This is an open access article distributed under the Creative Commons Attribution License which permits unrestricted use distribution and reproduction in any medium provided the original work is properly cited. A new inverse halftoning algorithm based on reversible data hiding techniques for halftone images is proposed in this paper. The proposed scheme has the advantages of two commonly used methods the lookup table LUT and Gaussian filtering methods. We embed a part of important LUT templates into a halftone image and restore the lossless image after these templates have been extracted. Then a hybrid method is performed to reconstruct a grayscale image from the halftone image. In the image reconstruction process the halftone image is scanned pixel by pixel. If the scanned pattern surrounding a pixel appeared in the LUT templates a gray value is directly predicted using the LUT value otherwise it is predicted using Gaussian filtering. Experimental results show that the reconstructed grayscale images using the proposed scheme own better quality than both the LUT and Gaussian filtering methods. 1. Introduction Inverse halftoning is a process which transforms halftone images into grayscale images. Halftone images are binary images that provide a rendition of grayscale images and .
