Blind watermarking for color images using EMMQ based on QDFT

In this study, we developed a novel scheme for the blind watermarking of color images. The proposed scheme incorporates extreme pixel adjustment (EPA), multi-bit partly sign-altered mean modulation (MPSAM), mixed modulation (MM), and particle swarm optimization (PSO) within a scheme based on crisscross inter-block quaternion discrete Fourier transform (QDFT). Accordingly, the proposed scheme employing EPA, MPSAM, MM, and QDFT is referred to as...