A Novel Public Digital Image Watermarking Algorithm

A novel public digital image watermarking algorithm for color images, by utilizing the technique of inter-block correlation of DCT coefficients, self-adjustment modification and random embedment, is proposed. It is embedded into color image watermark to DCT coefficients of color image luminance (Y) component. The entropy of image watermark information is greater than that of text or words watermark used in normal watermarking algorithms frequently. This algorithm can adaptively adjust the strength of embedded image watermark depending on the local feature of an original image to assure invisibility and maintain the quality of the original image. Further more, it could enhance the robusticity to non-geometric attack and loss compression, by embedding into DCT coefficients block random. Last but not the least, the embedded watermark can be extracted availably without the original image and the parameters used in embedding process, by utilizing the technics of inter-block correlation of DCT coefficients. Experimental results suggest that the proposed algorithm is one of the utilizing public watermark algorithm realizations.