Color image copyright ownership protection based on a multi-spectral selective pixel-wise watermarking technique

In this paper, an adaptive image watermarking technique is considered to be implemented for color image copyright protection. The proposed scheme is a modified pixel- wise (PW) masking technique where selective PW watermark locations (SPW) are defined to be candidates for watermark bit insertion. Here, the insertion is implemented to each spectral component of the RGB image, and, thus denoted as Multi- Spectral SPW (MS-SPW). Simulations have shown that using MS-SPW method, the image quality (PSNR) has been improved by an average value of 3-6 dB, when compared to results obtained based on the PW method without loosing the invisibility and robustness against attacks. In addition, the proposed MS-SPW method allows adapting the watermark size based on the selected locations. Simulations have also shown that MS-SPW method is robust to different types of attacks including JPEG compression.