A new wavelet based logo-watermarking scheme

摘要

A new wavelet based logo-watermarking scheme for copyright protection of digital image is presented. Instead of using a noise type Gaussian sequence, a visually meaningful gray scale logo is used as watermark. Watermark embedding process is carried out by transforming both the image and logo in wavelet domain. To embed the watermark robustly and imperceptibly, watermark bits are added to the significant coefficients of each subband selected by considering the human visual system (HVS) characteristics. A scheme is developed for reliable extraction of watermark from distorted images. From the experimental results it can be observed that proposed method is robust to wide variety of attacks. Comparison with the existing methods shows the superiority of the proposed method.