Blind Watermarking Algorithm Based on Wavelet-Transform & Fractal Self-Similarity

Abstract

An algorithm for embedding a meaningful 2-bit watermark image in carrier image is proposed by using Zigzag image scrambling based on discrete wavelet transform (DWT) and fractal self-similarity, along the Hilbert fractal curve scan sequence in the intermediate frequency subimage of wavelet decomposition of a carrier image, according to the mask template of Sierpinski carpet. Extracting the embedded watermark does not need the original carrier image and the original watermark image, which is a blind watermark algorithm. By using fractal self-similarity and Sierpinski carpet mask, watermark information can be embedded into the non-central parts of the carrier image repeatedly N times .The algorithm has shown the higher watermark imperceptibility and robustness under cutting and falsifying attacks of image, which is proved to be true by experimental results. The algorithm can be applied in DRM to protect digital image copyright.