Watermarking of digital images is a well-known technique that is widely used for securing image contents. A successful watermarking method must be accurate, reversible, resilient, and robust against various attacks. In this paper, we propose a reversible and robust color image watermarking method. A new set of multi-channel fractional-order polar harmonic transforms and their geometric invariants have been derived. These highly accurate and geometrically invariant features are used in the watermarking process. The binary watermark’s bits were scrambled using a 1D chaotic sine map to increase the security level. A set of experiments were performed to evaluate the proposed watermarking method, and its performance was compared with recent color image watermarking methods having similar colors. The obtained results showed high visual imperceptibility and superior robustness against geometric and signal processing attacks.

数字图像的水印是众所周知的技术，广泛用于保护图像内容。成功的水印方法必须准确、可逆、有弹性并且能够抵抗各种攻击。在本文中，我们提出了一种可逆且鲁棒的彩色图像水印方法。已经导出了一组新的多通道分数阶极谐波变换及其几何不变量。这些高度精确且几何不变的特征用于加水印过程。使用一维混沌正弦图对二进制水印的位进行加扰以提高安全级别。进行了一组实验来评估所提出的水印方法，并将其性能与具有相似颜色的最新彩色图像水印方法进行比较。