The growth of new image technologies has created a need for techniques that can be used for copyright protection of digital images. One approach for copyright protection is to introduce an invisible signal known as a digital watermark in the image. In this paper a watermarking algorithm operating in the wavelet domain is presented. The watermarks are two-dimension self-orthogonal finite-length sequences which are embedded in the middle frequency wavelet coefficients. Watermark detection is

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... plished without the original image by computing the correlation between the watermarked coefficients and the watermarking code. Experiment results demonstrate that the proposed watermarking scheme is perceptual invisible and robust against attacks such as JPEG compression,additive noise and filtering.