A new digital image watermarking based on Finite Ridgelet Transform and extraction using ICA

This paper presents a new digital image watermarking based on Ridgelet Transform (RT) and extraction using Independent Component Analysis (ICA). Ridgelet transform is a new directional multi-resolution transform and is more suitable for describing the signals with high dimensional singularities. Finite Ridgelet Transform (FRIT) is a discrete version of ridgelet transform, which is a numerical precision as the continuous ridgelet transform and has low computational complexity. Comparing with wavelets, ridgelets find more application on image watermarking, hence it represents smooth and edge parts of image with sparsity, whereas wavelets represent only point singularities. In addition, the representation of ridgelets contains more directional information. Hence, in this work, a digital image watermarking using ridgelets is attempted to obtain high robustness and good imperceptibility. The embedded watermark is extracted using ICA which is based on blind source separation technique. The main advantage of this extraction technique is that it extracts the watermark in spatial domain itself and does not require any transformation process and also it does not require the original image. Simulation results of ridgelet based watermarking are compared with wavelet based watermarking algorithm for digital images. Performance measures like Peak Signal to Noise Ratio (PSNR) and Similarity Measure are calculated to evaluate the performance of Ridgelet based watermarking against various attacks. Results reveal that performance of ridgelet is better when compared to wavelets in digital image watermarking applications.