Abstract
In order to make one image have an ability to simultaneously cope with copyright protection, secret communication and data management, a novel technique combining data hiding with digital watermarking is presented in this paper. Firstly, the proposed mechanism embeds the watermark image into the host one on the DCT frequency domain using the concept of mean quantization integrating the human visual system characteristics to achieve more robustness and invisibility. Then it embeds the important information into the covered image on the spatial domain using the modified LSB method to reduce the distortion of the covered image induced by the simple LSB substitution method. The proposed method has the following advantages : (1) For the digital watermarking, the proposed scheme using the concept of mean quantization improves the robustness of the watermark image but not affects the quality of the host image by means of JND. (2) For the data hiding, the modified LSB substitution method is capable of embedding the same payload the simple LSB method embeds but not inducing the same distortion the simple LSB method induces. (3)Because it does not require the original image in the extraction process, the security can be guaranteed. Furthermore, to enhance robustness, a random permutation of the embedded data is used to defeat the attacks of image processing, such as image cropping.