A New Robust Color Image Watermarking Method For Multimedia Technology Enhanced Learning Protection

In multimedia technology enhanced learning, digital watermarking is an important technique for protecting copyrighted multimedia materials. In this paper, we propose a robust color image watermarking scheme using quaternion geometric Legendre moment invariants (QGLMIs). Firstly, the original image is divided into color image blocks. Then, the Quaternion Discrete Cosine Transform (QDCT) is performed on the color image block. Finally, the digital watermark is embedded into original color image by adaptively modulating the real QDCT coefficients of color image block. For watermark detecting, the LS-SVM correction with low-order QGLMIs is utilized. Experimental results show that the proposed color image watermarking is not only invisible and robust against common image processing operations (especially for color attacks), but also robust against geometrical distortions.