This study systematically investigated the use of singular value decomposition (SVD) for the blind watermarking of color images. The proposed algorithm overcomes most of the problems typically encountered when using existing SVD-based schemes, while concurrently enhancing performance in terms of imperceptibility and robustness. After applying SVD to non-overlapping 4 × 4 image blocks, level shifting is used to control the embedding strength in accordance with the intensity of pixels in each block. The proposed watermark embedding process helps to preserve orthonormality in the unitary matrix and compensate for the resulting distortion. Iterative regulation ensures the accurate retrieval of the embedded watermark, while mixed modulation helps to improve robustness without compromising image quality. Experiment results demonstrate that the proposed watermarking algorithm is highly resistant to a variety of image processing attacks and error-free in the absence of attack. The proposed method outperforms existing SVD-based schemes in terms of imperceptibility and robustness at a payload capacity of 1/16 bit per pixel.

这项研究系统地研究了奇异值分解（SVD）在彩色图像的盲水印中的应用。所提出的算法克服了使用现有的基于SVD的方案时通常遇到的大多数问题，同时在不易察觉性和鲁棒性方面同时提高了性能。在将SVD应用于不重叠的4×4图像块后，根据每个块中像素的强度，使用电平移动来控制嵌入强度。提出的水印嵌入过程有助于在the矩阵中保持正交性并补偿由此产生的失真。迭代调节可确保对嵌入水印的准确检索，而混合调制有助于提高鲁棒性，而不会影响图像质量。实验结果表明，所提出的水印算法对各种图像处理攻击具有很高的抵抗力，并且在没有攻击的情况下没有错误。在每像素1/16位的有效负载容量方面，拟议的方法在不易察觉性和鲁棒性方面优于现有的基于SVD的方案。