PHT矩分解。用于音频或者图像数据的极谐波变换，使音频数据在受攻击后仍能够较好的提取水印-PHT matrix decomposition.Audio frequency or image data of Fourier transform, the audio data in attack can still good after extracting the watermark

基于PHT和小波变换的数字水印技术。具有良好的鲁棒性。-Digital watermarking technology based on PHT and wavelet transform.Has a good robustness.