Robust Color Image Watermarking Using Dual Embedding via Schur Decomposition

Abstract

This research introduces a Schur-based watermarking technique that employs a 4´4 matrix block and a two-phase embedding process to enhance robustness performance. The watermark bits are scrambled with a key to obtain scrambled watermark. The two watermark bits are embedded into the c-th vector of Schur decomposition. In addition to achieving a remarkable trade-off between imperceptibility and robustness, this study investigates the relationship between c-th vector of Schur decomposition to achieve balancing between invisibility and robust against several attacks. Evaluation results demonstrate outstanding performance in preserving the integrity and resilience of the watermark across various colour images. The method achieves high PSNR values, indicating excellent watermark extraction quality with minimal distortion to the images. Furthermore, comparisons with earlier approaches highlight its superior resistance to attacks on test images. The experimental results show the proposed scheme has an ability to maintain image quality and withstand attacks, the proposed method shows significant potential for copyright protection with average SSIM value of 0.9939 and an average NC of 0.9118 under various attacks.