A watermarking scheme for dual-color images based on URV decomposition and image correction

In view of the fact that many watermarking schemes cannot well adapt to the occasion of image copyright protection with a large amount of information, and the copyright protection of color image is facing severe challenges, a dual-color image watermarking scheme based on URV decomposition (URVD) and image correction is designed in this paper. The two-dimensional Logistic-adjusted-Sine map is first used to generate two chaotic sequences for pixel-level scrambling and bit-level diffusion of the watermark image, and URVD is applied to watermarking scheme. After fully considering the relationship between image channels, the watermark is embedded into the maximum URVD coefficient by using quantization index modulation based on variable quantization steps. The greatest contribution of this paper is to propose a new image correction algorithm as a pretreatment of watermark extraction, which mainly includes fast detection of feature points, image correction, and sawtooth processing, and it solves some problems existing in image correction algorithms based on geometric characteristics. Experimental results show that the proposed scheme has good invisibility, strong robustness, and high security. Compared with existing schemes, the proposed scheme has better performance under the same actual embedding rate, especially stronger and more effective robustness against some common geometric attacks.