A Blind Watermark Algorithm in Color Image Based on Mixed Transform Domain

Using chaotic sequence for encryption and location is proposed, an algorithm in color image, which embeds binary watermark in mixed transform domain and adapts to gray watermark dividing the color image into <em<RGB</em< values. Discrete wavelets transform is adopted in every value and discrete cosine transform in low-frequency discrete wavelet transform(DWT) areas. Chaotic sequence are used to locate the watermark information in discrete cosine transform(DCT) domain. The watermark information is embedded by the comparison of frequency coefficients. The experimental results showed that the algorithm has a good robustness against noise, image processing, malicious attacks, and image compression. It enhances the security capability.