Multiresolution fragile watermarking using complex chirp signals for content authentication

Abstract

This paper proposes a wavelet-domain multiresolution fragile watermarking scheme using an improved quantization-index-modulation (QIM) embedding technique. A secure embedding zone is exploited in our proposed scheme to reduce the false detection rate of Kundur's scheme. The frequency modulated (FM) complex chirp signal is employed as watermark. Both the real and the imaginary parts of the chirp signal are embedded simultaneously in a hierarchical manner. Unlike the conventional schemes, the proposed scheme does not require the original watermark for content integrity verification and quality assessment for the distorted watermarked content. The blind authentication process allows embedding of arbitrary FM chirp watermarks.