A Zero-watermarking Algorithm of Color Image Based on SVD and DWT

In order to enhance the robustness of watermark technology, a zero-watermark is proposed based on color image using block singular value decomposition (SVD) under the discrete wavelet transformation (DWT) .It conducts DWT with the original image, divides its low frequency band into blocks, and conducts SVD with every block.Zero-watermark is generated by the decomposition of the former largest singular values of mof the block matrix.Experiments show that the proposed algorithm has strong robustness against various attacks.