A Robust Multilevel Watermarking Method for Digital Images using Multiresolution Wavelet Decomposition

Abstract

A multiresolution wavelet transformation based novel and robust multilevel watermarking method is introduced. The transformed watermark coefficients are embedded into those of the host image using the presented method. Watermark is extracted by inverse transformation at every level by feeding the residual marked image from previous level to the next. Finally, the watermark is estimated by taking mean value of the obtained watermarks. The introduced method is tested on six gray level images with added Gaussian, salt and pepper, Speckle, and joint photographic experts group (JPEG) noises, using signal to noise ratio and correlation coefficients as similarity measure.