Browsing by Author "Chien, Chih-Cheng"

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A wavelet-based semi-fragile watermarking with recovery mechanism
(2008)
Tsai, Min-Jen
;
Chien, Chih-Cheng
;
資訊管理與財務金融系註：原資管所+財金所
;
Department of Information Management and Finance
This paper studied the wavelet transformation based watermarking tamper detection and recovery scheme. By the property of discrete wavelet transform, we design the semi-fragile watermark from low-frequency band and embedding the watermark into the high-frequency band by the help of Human Visual System (HVS). The watermarked image still preserves high image quality after the embedding of the semi-fragile watermark and the image authentication system is able to locate precisely any malicious alteration made to the image. Our novel design can restore the altered or destroyed regions from the attacked images and allow the users to know what the original content was in the manipulated areas. We also analyze the robustness for mild modification like JPEG compression and channel additive white Gaussian noise (AWGN) and fragility to malicious attack. In summary, this scheme can resist the mild modifications of digital image and be able to detect the malicious modifications precisely.
Authentication and recovery for wavelet-based semifragile watermarking
(2008-06-01)
Tsai, Min-Jen
;
Chien, Chih-Cheng
;
資訊管理與財務金融系註：原資管所+財金所
;
Department of Information Management and Finance
We propose a novel image authentication and recovery scheme based on discrete wavelet transform (DWT). By using the property of a DWT multiresolution structure, we generate a semifragile watermark from low-frequency bands and embed the recovery information into the high-frequency bands based on the human visual system (HVS) approach. The image authentication system is able to locate precisely any malicious alteration made to the image and restore the altered or destroyed regions based on the recovery mechanism. Therefore, the requirements of ownership protection and tampering detection of digital right management (DRM) are met, and the legal usage of digital content is available. In addition, robustness to mild modifications like JPEG compression and channel additive white Gaussian noise (AWGN) is also achieved with high recovery image quality. (C) 2008 Society of Photo-Optical Instrumentation Engineers.