A new gray-scale watermark method based on irregular LDPC codes with Unequal Error Protection (UEP)
Yunxia Lin, Yi Wan · Proceedings of SPIE, the International Society for Optical Engineering/Proceedings of SPIE · 2016
In this paper, we propose a discrete wavelet transform (DWT)-singular value decomposition (SVD) gray-scale image watermark method based on the irregular Low-density Parity-check (LDPC) codes with unequal error protection (UEP). As one of the best effective ways of protecting copyright of multimedia data, digital watermark technology is widely researched by experts and learners. The difficulty of researching gray-level watermark lies in large embedding capacity. As there exists most important parts, less important portions and non-important materials in the gray-level watermark image, it is not reasonable to treat equally different parts of gray-level watermark image. According to this idea, we put forward the method by using irregular LDPC codes with UEP to protect different importance-level parts. The high degree bits protect important parts, the low-degree bits protect non-important portions. The experimental results indicate that the proposed scheme can apparently achieve high imperceptibility of embedded image and high robustness defined by the peak signal to noise ratio (PSNR) against image processing attacks.