A Novel Blind Watermark Extraction Algorithm Based on Nonsubsampled Contourlet Transform
Lei Feng, Xiao Fei Shi, Hong Yu Chen, Yan Hua Li, Yue Long Zhang · Advanced materials research · 2014
Most existing watermark extraction algorithms were dependent on prior knowledge. This paper proposed a blind extraction method without relying on prior knowledge. According to constructing new observation based on nonsubsampled contourlet transform, which utilizes low frequency and directional components of watermarked image, more independent components are generated. We involve these components into watermarked image and resort this solution to multichannel blind source separation. Estimated watermark is recovered by ICA algorithm. Experiment results indicate that the proposed method can achieve better results in contrast with two existing algorithms.