Optimal pixel-level self-repairing authentication method for grayscale images under a minimax criterion of distortion reduction

Abstract

A new blind pixel-level self-repairing grayscale image authentication method, which is optimal under a minimax criterion of image-distortion reduction, is proposed. By dividing the grayscale range into bins, a three-bit bin code which provides the double functions of tampering localization and data repairing is generated as the authentication signal for each pixel in the cover image. The optimality in choosing three bits of a pixel as the authentication signal under a minimax criterion of minimizing the total maximum distortion resulting from authentication signal embedding and tampered pixel repairing is proved. Experimental results show the effectiveness of the proposed method. (C) 2012 Society of Photo-Optical Instrumentation Engineers (SPIE). [DOI: 10.1117/1.OE.51.5.057006]