In this article, we presented a new blind image watermarking method based on the exploitation of non-zero high frequency coefficients in blocks transformed by Wavelet. The intra image (I) of the international standard of image compression are chosen to insert the watermark, and then their luminance is very small (multiplied by α) and transformed by DCT (Discrete Cosins Transform). We inserted LH of the mark into the non-zero high frequency coefficients of the blocks in the image. During the detection process, the correlation between the watermarking and the non-zero high-frequency transformed coefficients is calculated to judge whether the image has been watermarked. The experimental results indicate that the amplitude of the correlation peaks corresponds to the watermarked image. The proposed watermarking method has strong robustness to some known attacks such as image filtering, image compression, collusion attack, over-marking attack.

Wavelet, Discrete Cosins Transform DCT, Watermarking method, Correlation.