Watermarking Algorithm Based on Chaotic System and Discrete Cosine Transform Domains

This paper proposes a image-based watermarking algorithm,which embeds a binary image as the watermark.Adapting Toral Automorphism system,which belong to theory of Strong Chaotic System,firstly,the watermarking algorithm disorders the binary image used as the watermark.Then the algorithm carries out discrete cosine transform on the blocks of a gay scale image used as the carrier of watermark and then uses quantization matrix depicted in JPEG standards,which are used when a image needs a relatively high compression rate,to quantize the DCT coefficients.After the quantizing of the DCT coefficients,some statistical characteristics of the coefficients which are still not equal to zero will be used to implement the embedding of the watermark.Given the embedding course of watermark mentioned above,this watermarking algorithm is expected to have great robustness,specially to JPEG compressing,and watermark embedded through this watermarking algorithm be invisible.