将网格编码技术与固定鲁棒性嵌入相结合提出了一种新的网格编码水印算法。该算法将带边信息的编码和带边信息的嵌入技术相结合，首先运用脏纸网格对水印信息进行编码，然后计算使水印系统归一化相关检测系数降到给定阈值时所能抵抗的噪声幅度，并将其作为鲁棒性参数，在恒定的鲁棒性参数下利用规格化正交嵌入水印，用维特比算法进行水印检测。实验结果表明，该算法有效地提高了基于网格编码的数字水印系统抵抗高斯噪声和幅度缩放的能力。

In this paper, a new trellis coded watermarking algorithm of trellis codes combine with constant robustness embedding is proposed. In the algorithm, both informed coding and informed embedding are used. The watermark is encoded by a dirty paper trellis encoder. Then the strength of the noise to be added to reduce the normalized correlation coefficient to a given threshold is computed, which is taken as a constant robustness parameter. The watermark signal is embedded into the cover work by Gram Schmidt orthogonal algorithm under the condition of the constant robustness parameter, and Viterbi algorithm is used to detect and extract the watermarked signal. Experimental results indicate that the proposed algorithm can improve the robustness to white Gaussian noise and amplitude scaling.