Robust Blind Watermarking Method for High Capacity RGB Image in Wavelet Domain

Image watermarking is a tool to maintain the authentication and copyright protection of digital documents.RGB image is one of the media that is extensively distributed and transferred by the cloud.This type of digital data can be protected by hiding watermark protection logos.Furthermore, this type of images presents a media that can be used to hide more than one watermark.In this paper, a novel RGB image watermarking method based on DWT is used to embed three watermark logos, instead of one watermark logo.In each color channel, a watermark logo is embedded to increase the authentication criteria and capacity payload.To improve the robustness and invisibility, the wavelet transform is exploited to hide the watermark data in low-frequency bands rather than the pixel values.The proposed method is evaluated using three metrics, PSNR, NCC, and HD.The robustness of the proposed method is tested under various attack types, such as the noise, filter, and sharpening attacks.The experimental results show that the proposed RGB watermarking method has a good trade-off between robustness and invisibility and resistance to several attacks in the watermarked image.The method has been evaluated against various attacks (e.g., noise, filtering, compression, sharpening), demonstrating strong robustness while maintaining high image quality and achieving PSNR values between 37.8 and 51.2 dB.The proposed scheme outperforms several existing DWT-based RGB watermarking methods, showing a better trade-off between robustness, imperceptibility, and watermark capacity.