图像水印系统和通信系统的模式具有相似性。为了提高数字水印的鲁棒性和降低传输过程的差错，在研究低密度奇偶校验码（low density parity check，LDPC）在数字水印中的应用的基础上，提出了一种基于LDPC码的图像数字水印技术。该技术利用了LDPC码的纠错性能和图像的人眼视觉特性，实现了静止图像中数字水印的嵌入和提取；实验结果表明，该技术不仅降低了水印在传输过程中的差错率，而且可以达到提高埋藏水印的鲁棒性和隐匿性的目的。

The goal of this paper was to investigate the application of the LDPC codes in Digital image watermarking. Based on the analysis of the equivalent channel in the digital watermarking system, a watermarking technique for digital image on the basis of LDPC code is proposed. The algorithm embeds and retrieves the watermark signature into and out of the static image by employing the LDPC code technology and the human visual characteristics. The results demonstrate that the proposed technique has greatly decreased the error code rate of the retrieved watermark and improved the robustness and invisibility.