A Robust Image Watermarking Algorithm in DCT Domain Based on Chaotic Projection

As the internet technology advances, various types of digital products have become more open and transparent in the process of online transmission. At the same time, there have also been some issues of tampering, piracy, and infringement. The digital watermarking is a important and necessary means of copyright protection. This article mainly focuses on the issue of image privacy and copyright protection, and proposes a robust image watermarking algorithm in DCT (discrete cosine transform) domain based on chaotic projection. Firstly, the host image is divided into blocks through the block processing. Besides, we perform the DCT transform on each sub-block image. Performing complementary transformation on them and the watermark image to be embedded by selecting a appropriate coefficients. Finally, we use Arnold scrambling transformation and chaos mapping technology to encrypts watermark image, realizing the embedding and hiding of digital watermark images. The simulation results show that the embedded watermark image has good concealment and transparency, and it has strong resistance to Gaussian interference, JPEG compression and clipping attacks.