9. Robust Hybrid Watermarking Algorithm Based on DCT-PMF-DWT-SVD

This chapter introduces a robust hybrid watermarking algorithm that combines Discrete Cosine Transform (DCT), Pixel Movement Function (PMF), Discrete Wavelet Transform (DWT), and Singular Value Decomposition (SVD) to enhance digital image security. The algorithm's effectiveness is demonstrated through various attacks, including Salt and Pepper noise, Gaussian noise, median filtering, average filtering, Gaussian low-pass filtering, sharpening filter, rescaling, rotation, translation, gamma correction, histogram equalization, and JPEG compression. The evaluation metrics used are Peak Signal-to-Noise Ratio (PSNR) and Normalized Correlation (NC), which confirm the high visual quality of the watermarked images and the strong similarity between the inserted and extracted watermark. The algorithm's robustness is further validated through a comparison with a previously published method, showcasing better NC values under different types of attacks. The chapter concludes with a suggestion for implementing the algorithm on a DSP processor to assess its practical performance.