随着计算机网络技术与多媒体技术的快速发展,数字产品的版权保护已经成为信息技术领域中最重要的问题之一,提出了一种新颖的基于离散小波变换的数字水印方案,该方案利用改进的Patchwork算法,将水印嵌入到LL子带中,水印信号在解码过程中无需使用原始图像就可快速地重嵌入,该算法利用BCH码来降低误码率.应用所提出的算法,把一个32个字符的水印嵌入到图像中,实验结果表明水印是不可察觉的,经过JPEG有损压缩、低通与中值滤波等图像处理操作后仍是鲁棒的.

With the rapid spread of computer networks and the further progress of multimedia technologies, copyright protection of digital media has been one of the most important issues in information technology field. A novel digital watermarking scheme using discrete wavelet transform is presented. The scheme embeds watermark in LL subband by modified Patchwork algorithm. The watermark signal can be extracted in decoding process without original image and can be rapidly remarked. The error probabilities of decode is reduced by exploiting BCH code. With the proposed algorithm, a meaningful watermark composed of 32 characters is embeded into image. Experimental results show that the watermark is perceptually invisible and the proposed scheme is robust to some image processing operations such as lossy JPEG defective compression, low pass filtering, median filtering.