Multimedia watermarking with complex Hadamard transform in the inverse pyramid decomposition

A new method for digital watermarking of multimedia signals (audio signals and images) is offered, based on decomposition with inverse difference pyramid (IDP), whose coefficients are obtained with complex Hadamard transform (CHT). Advantages of the method, compared with those based on DFT or DWT transform, are that there is no quantization of the values of the transform coefficients; it has lower computational complexity and permits insertion of different watermark in every consecutive pyramid level. The method ensures practical invisibility (insensibility) of the inserted watermark, and high resistance against tampering, compression, affine transforms, filtration, dithering and other kinds of processing. Together with this, the method permits sure detection of the inserted watermark and low probability for mistakes in the water mark extraction.