In unsecured network environments, ownership protection of digital contents, such as images, is becoming a growing concern. Different watermarking methods have been proposed to address the copyright protection of digital materials. Watermarking methods are challenged with conflicting parameters of imperceptibility and robustness. While embedding a watermark with a high strength factor increases robustness, it also decreases imperceptibility of the watermark. Thus embedding in visually less sensitive regions, i.e., complex image blocks could satisfy both requirements. This paper presents a new wavelet-based watermarking technique using an adaptive strength factor to tradeoff between watermark transparency and robustness. We measure variations of each image block to adaptively set a strength-factor for embedding the watermark in that block. On the other hand, the decoder uses the selected coefficients to safely extract the watermark through a voting algorithm. The proposed method shows better results in terms of PSNR and BER in comparison to recent methods for attacks, such as Median Filter, Gaussian Filter, and JPEG compression.

中文翻译：

---

使用动态强度因子的鲁棒基于小波的水印

在不安全的网络环境中，对数字内容（例如图像）的所有权保护越来越受到关注。已经提出了不同的水印方法来解决数字材料的版权保护问题。水印方法面临着不可察觉性和鲁棒性的冲突参数的挑战。虽然嵌入具有高强度因子的水印增加了鲁棒性，但它也降低了水印的不可察觉性。因此嵌入在视觉上不太敏感的区域，即复杂的图像块可以满足这两个要求。本文提出了一种新的基于小波的水印技术，使用自适应强度因子在水印透明度和鲁棒性之间进行权衡。我们测量每个图像块的变化，以自适应地设置一个强度因子，用于在该块中嵌入水印。另一方面，解码器使用选定的系数通过投票算法安全地提取水印。与最近的攻击方法（例如中值滤波器、高斯滤波器和 JPEG 压缩）相比，所提出的方法在 PSNR 和 BER 方面显示出更好的结果。