Robust and Blind Watermarking for DIBR Using a Depth Variation Map

This paper proposes a digital watermarking scheme to protect the ownership of the freeview 2D or 3D image such that the viewer watches the image(s) by rendering a arbitrary viewpoint image(s) with the received texture image and its depth image. In this case a viewpoint change attack essentially occurs, even if it is not malicious. In addition some malicious attacks should be considered, which is to remove the embedded watermark information. In this paper, we generate a depth variation map (DVM) to find the locations less sensitive to the viewpoint change. For each LH subband after 3-level 2DDWT for the texture image, the watermarking locations are found by referring the DVM. The method to embed a watermark bit to a pixel uses a linear quantizer whose quantization step is determined according to the energy of the subband. To extract the watermark information, all the possible candidates are first extracted from the attacked image by considering the correlation to the original watermark information. For each bit position, the final extracted bit is determined by a statistical treatment with all the candidates corresponding that position. The proposed method is experimented with various test images for the various attacks and compared to the previous methods to show that the proposed one has excellent performance. Keyword : digital image watermarking, freeview 2D/3D image, viewpoint change, depth variation map (DVM) a) 광운대학교 전자재료공학과(Department of Electronic Materials Engineering, Kwangwoon University) b) 광운대학교 교양학부(School of Liberal Arts, Kwangwoon University) ‡Corresponding Author : 김동욱(Dong-Wook Kim) E-mail: dwkim@kw.ac.kr Tel: +82-2-940-5167 ORCID: http://orcid.org/0000-0002-4668-743X ※이 논문의 연구결과 중 일부는 “2016년 한국방송.미디어공학회 하계학술대회”에서 발표한 바 있음. ※이 연구는 2014년도 정부(교육부)의 재원으로 한국연구재단의 지원을 받아 수행된 기초연구사업임(NRF-2013R1A1A2057798). ・Manuscript received June 23, 2016; Revised November 16, 2016; Accepted November 16, 2016. Copyright C 2016 Korean Institute of Broadcast and Media Engineers. All rights reserved. “This is an Open-Access article distributed under the terms of the Creative Commons BY-NC-ND (http://creativecommons.org/licenses/by-nc-nd/3.0) which permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original work is properly cited and not altered.” 특집논문 (Special Paper) 방송공학회논문지 제21권 제6호, 2016년 11월 (JBE Vol. 21, No. 6, November 2016) http://dx.doi.org/10.5909/JBE.2016.21.6.845 ISSN 2287-9137 (Online) ISSN 1226-7953 (Print) 846 방송공학회논문지 제21권 제6호, 2016년 11월 (JBE Vol. 21, No. 6, November 2016)