Digital Image Watermarking

Digital image watermarking is a critical technique for protecting multimedia data from unauthorized copying, tampering, and distribution. This review explores a hybrid approach that combines Discrete Wavelet Transform (DWT), Singular Value Decomposition (SVD), and Particle Swarm Optimization (PSO) to enhance the performance of watermarking schemes. The method addresses key challenges such as false positives and diagonal line problems in SVD-based watermarking by embedding principal components of the watermark into the host image’s sub-bands using an optimized scaling factor derived from PSO. The proposed scheme ensures high robustness against attacks while maintaining imperceptibility and fidelity. Experimental evaluations demonstrate superior results in terms of Peak Signal-to-Noise Ratio (PSNR), Structural Similarity Index (SSIM), and Normalized Correlation (NC). This work highlights the relevance of optimization techniques in improving copyright protection for digital images.