Abstract
In the recent years, the growth of applications on network and multimedia techniques has become very popular. Because of such growth of network multimedia systems, how to protect the ownership has created a need for techniques that can be used for copyright protection of digital media. The image copyright protection involves the authentication of image ownership and can be used to identify illegal copies of images. One approach for image copyright protection is to introduce an invisible signal as a digital watermark in the image.In this paper, we propose a wavelet-based invisible watermarking technique by a data structure based on the parent-child dependencies of subbands of images. This kind of parent-child dependencies of subbands of wavelet coefficients is applied to select significant blocks of wavelet coefficients to increase watermark robustness and reduce distortion. Another blind watermarking technique is proposed to embed the watermark and detect the embedded watermark in the wavelet domain without the information of the original image. Experimental results show that the invisible watermarking scheme is robust at the attack of the JPEG compression and various image procession techniques. The blind watermark extracting scheme can retrieve the embedded watermark successfully without the help of the original image after the JPEG and wavelet-based compression schemes even under very high compression ratio.