Research on heart sound digital water-marking based on heart sound wavelet

In the aspect of heart sound signal processing, the heart sound database copyright protection is very important. As a kind of special audio signal, there is no deep research on the heart sound watermark processing. This article first studies some basic characteristics of heart sound signal and the theory of digital watermarking technology, and then combined with the characteristics of heart sound signal, respectively using db5 wavelet and self-constructed heart sound wavelet embed three different watermarking (image, voice, and four corner code) into the heart sound signal. Based on the transparency, robustness and invisibility test experiment of the embedded watermark information and extracted watermark information, each type of watermarking are compared and analyzed quantitatively and qualitatively. The experimental results show that the four corner code watermarking of heart sound based on wavelet is more suitable for heart sound signal, the effective implementation of heart sound digital watermarking embedding and extraction. The embedded watermark information is not only better imperceptibility, but also larger energy, with strong practical value.