wtmk

代码说明：

说明：  通过生成秘钥得到一串具有一定长度的扩频码，将原始消息序列以扩频码的长度过采样产生过采样消息序列，并将扩频码以原始消息序列的长度多次重复成伪随机序列，再令过采样消息序列与伪随机序列异或就可以生成扩频消息序列。在频率域下，将扩频消息序列以一定的嵌入强度自适应地嵌入原始图像，得到的图像具有较强的鲁棒性，比起直接嵌入，扩频水印在受到攻击后恢复出的水印信息误码率要低得多。并且扩频码长度越长，容错率就越高，鲁棒性就越好。(A sequence of spread spectrum codes with a certain length is obtained by generating a secret key. The oversampling message sequence is generated by oversampling the original message sequence with the length of the spread spectrum code, and the spread spectrum code is repeated into a pseudo-random sequence with the length of the original message sequence for many times, and then the spread spectrum message sequence can be generated by making the difference between the oversampling message sequence and the pseudo-random sequence. In the frequency domain, the spread spectrum message sequence is adaptively embedded into the original image with a certain embedding strength, and the resulting image has strong robustness. Compared with direct embedding, the error rate of the watermark information recovered from the attack of spread spectrum watermark is much lower. And the longer the spreading code length, the higher the fault tolerance rate and the better the robustness.)

文件列表：

wtmk\sourceimg.jpg, 6741380 , 2019-06-16
wtmk\sourceimg1.jpg, 25911 , 2016-05-22
wtmk\sourceimg1960x1225.jpg, 949788 , 2019-06-16
wtmk\sourceimg2.jpg, 1216618 , 2020-04-12
wtmk\watermark.jpg, 24684 , 2019-06-16
wtmk\wtmk.m, 3657 , 2019-06-16
wtmk, 0 , 2020-04-12