A robust watermarking scheme based on steerablepyramid and singular value decomposition

摘要

Most of the watermarking schemes that have been proposed untilnow are based on DCT, DFT, and DWT transformations. For this rea-son, this paper presents a new robust watermarking scheme based onSteerable Pyramid (SP) wavelet transform and singular value decom-position (SVD) for copyright protection and authenticity. SP transfor-mation is applied to the original image with a number of scales andorientations accurately calculated. Low-pass band is selected and di-vided into blocks. After applying SVD on each block, watermarkingprocess embeds the watermark by modifying coe cient of S componentof each block. For each block we get a secret key that will be used forthe extraction of the watermark. Peak signal to noise ratio (PSNR)is used to evaluate the watermarking schemes. Extracted watermarkquality is evaluated by Normalized cross correlation (NC). Experimen-tal results show the e ectiveness of this method with good visual qualityand resistance against several attacks.