This article discusses a joint encryption-then-compression-based watermarking scheme for copyright protection and content verification in variety of applications. In this scheme, redundant discrete wavelet transform is first performed to decompose the nonsubsampled contourlet transform host image, and then, the singular value decomposition is applied on transformed coefficients of the host image. Furthermore, same procedure is applied for both watermarks (image and PAN No.). The PAN number is encoded by the quick response (QR) code before hiding into the host image. Finally, 2D hyperchaotic encryption is used to encrypt the watermarked image to make our method more secure against attacks. After this, the encrypted image is then compressed via Huffman compression to reduce the size of the image at an acceptable quality of the reconstructed image. Furthermore, performance outcomes confirm better robustness and security of the method while preserving the image quality.

中文翻译：

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基于加密后压缩的电子政务版权保护方案

本文讨论了一种基于联合加密然后压缩的水印方案，用于各种应用中的版权保护和内容验证。该方案首先进行冗余离散小波变换对非下采样Contourlet变换宿主图像进行分解，然后对宿主图像的变换系数进行奇异值分解。此外，对两个水印（图像和 PAN 编号）应用相同的程序。PAN 号码在隐藏到主机图像之前由快速响应 (QR) 代码编码。最后，使用 2D 超混沌加密对带水印的图像进行加密，使我们的方法更安全地抵御攻击。在此之后，加密的图像然后通过霍夫曼压缩进行压缩，以在重建图像可接受的质量下减小图像的大小。