A robust watermarking technique based on biorthogonal wavelet transform

This paper presents a robust & invisible digital image watermarking technique using biorthogonal wavelet transform. The proposed method is founded more suitable for copyright protection and robustness than orthogonal wavelet transform based watermarking techniques. In proposing method the blue channel of the cover image is selected for embedding watermark because it is more resistant to changes compared to red and green channels. The blue channel is decomposed into n levels using biorthogonal wavelet transform because biorthogonal wavelet transform is an invertible transform and has the property of exact reconstruction and smoothness. The horizontal and vertical subbands are selected for embedding watermark. This method is shown to be robust against many signal processing operations as well as geometrical attacks.