说明：  一种基于DCT变换的数字水印算法的实现过程,水印为伪随机序列，包括嵌入和提取两个过程。其中textmark.m为攻击实验代码。
(DCT-based Digital Watermarking Algorithm Transform realize the process, the watermark for the pseudo-random sequence, including both the process of embedding and extraction. Textmark.m experiment in which the attack code.)