# A Hybrid Domain Color Image Watermarking Scheme Based on Hyperchaotic Mapping
###### Abstract  
In the field of image watermarking technology, it is very important to balance imperceptibility, robustness and embedding capacity. In order to solve this key problem, this paper proposes a new color image adaptive watermarking scheme based on discrete wavelet transform (DWT), discrete cosine transform (DCT) and singular value decomposition (SVD). In order to improve the security of the watermark, we use Lorenz hyperchaotic mapping to encrypt the watermark image. We adaptively determine the embedding factor by calculating the Bhattacharyya distance between the cover image and the watermark image, and combine the Alpha blending technique to embed the watermark image into the Y component of the YCbCr color space to enhance the imperceptibility of the algorithm. The experimental results show that the average PSNR of our scheme is 45.9382 dB, and the SSIM is 0.9986. Through a large number of experimental results and comparative analysis, it shows that the scheme has good imperceptibility and robustness, indicating that we have achieved a good balance between imperceptibility, robustness and embedding capacity. image watermarking; Lorenz hyperchaotic map; Bhattacharyya distance; discrete wavelet transform; discrete cosine transform [1] [2] [3] [4] [5] [6] [7] [8] [9] [10] [11] [12] [13] [14] [15] [16] [17] [18] [19] [20] [21] [22] [23] [24] [25] [26] [27] [28] [29] [30] [31] [32  
poor. Frequency domain watermarking is mainly realized by some commonly used image transformations. The pixels of the image are transformed into frequency coefficients by transformation, and then the watermark information is embedded in the frequency coefficients. The frequency domain algorithm greatly improves the robustness of the watermark, but the computational complexity is usually higher and the operation time is longer. Fourier transform (DFT), discrete wavelet transform (DWT), discrete cosine transform (DCT), singular value decomposition (SVD) and so on are commonly used frequency domain watermarking schemes. Robustness, imperceptibility, embedding capacity and security are the four core indicators to evaluate the performance of image watermarking algorithms. There is often a trade-off relationship between these indicators, that is, in practical applications, it is difficult to optimize these indicators at the same time. Alpha hybrid technology [6] can be used to solve this problem. By finely adjusting the embedding strength, a relatively balanced state can be found between these four evaluation indicators, so as to ensure certain robustness and security while minimizing the imperceptibility of the watermark. By adaptively calculating the embedding strength, the robustness of the watermark image can be significantly enhanced. In contrast, a fixed embedding strength may cause the watermark to be more easily damaged. Therefore, adaptive computing provides a more effective way to improve the performance of watermarking [7]. In the face of geometric attacks, the watermarking method based on wavelet transform shows a certain degree of vulnerability [8], but the extraction of image geometric features by matrix decomposition can overcome this limitation. The combination of wavelet transform and matrix decomposition is often used for watermark embedding, which aims to prevent image tampering and resist geometric attacks. In addition, due to the concentration of DCT coefficients in the low-frequency part of the image, the image can still maintain good stability when experiencing compression, clipping, rotation and other operations [9]. In addition, color space also plays an important role in image watermarking technology. In particular, the YCbCr color space separates the brightness information (Y component) from the chromaticity information (Cb and Cr components). Among them, the Y component expresses the brightness of the image, while the Cb and Cr components carry the color information of the image.