An Improved Chirp Typed Blind Watermarking Algorithm Based on Wavelet and Fractional Fourier Transform
Dianhong Wang, Dongming Li, Jun Yan, F. Chen · 2007
Spatial domain-based chirp signal watermark can be detected blindly through the fractional Fourier transform in the transform domain. The purpose of this paper is to outline the state of the research of wavelet transform domain-based watermark and to propose an improved algorithm towards it. With regard to the later we first analyze the optimum order of the Hermite matrix for the computation of direct discrete Fourier transform. Then we focus on chirp signals hiding in the low frequency band of the host image in wavelet domain. Results of the experiments revealed that our improved blind watermark detection algorithm is more robust comparing with conventional spatial algorithm. In addition, it detects the chirp watermark rapidly.