A new algorithm for watermarking based On DCT and chaotic scrambling

This paper presents a robust image watermarking method in discrete cosine transform (DCT) domain based on chaotic sequences encryption. Exploiting some characteristics of human visual system (HVS) and DC(direct current) components having much larger perceptual capacity than any AC (alternating current)components, watermark is embedded into the DC components of the host image. First, we scramble the watermark image to avoid the block effect. Then we split the host image and the scrambled watermark image into 8times8block respectively, and the scrambled watermark is embedded into the DC components of the host image. The experimental results show that the embedded watermark is invisible and robust against noise and commonly used image processing methods such as Gaussian, JPEG compression, Median filtering etc.