A Blind Watermarking Algorithm Based on Color Space Conversion in DCT Domain

Considering the shortcomings of exiting watermarking algorithm, an adaptive robust blind watermarking algorithm in DCT Domain is proposed. It divides color image luminance component into 8×8 bocks for DCT transform in Color Space, then embeds binary watermark in its middle frequency coefficients in DCT domain, therefore, the embedding and extraction of the binary watermark in color image carrier can be achieved relatively well and blind extraction, to get the watermark without original image, is possible. The simulation results show that the algorithm guarantees a good color image quality and can achieve excellent robustness against attacks such as Gaussian, Salt, Mosaic and Speckle attacks, etc.