Robust watermarking algorithm of color image based on DWT-DCT and chaotic system

This paper elaborates an algorithm of robust image watermarking schema which is focus on embedding RGB watermark into RGB color image. The algorithm is based on discrete wavelet transform (DWT), discrete cosine transform (DCT) and chaotic system. The schema applies a self-adapted watermark image, according to the color image R, G, B components of the lightest weight selection. Watermark image is encrypted by the logistic mappings. Due to the correlation between the low frequency coefficients, DWT transform will strengthen the values of coefficient, hence it is not benefit of increasing the imperceptibility of the watermarks. This paper uses the features of DCT to reduce the correlation between DWT coefficients. According to simulation results, the watermarking schema satisfies high robust anti-attacked from such as JPEG compression, Gaussian noise, filtering etc.