Cultural Heritage Copyright Protection: A blind and robust watermarking technique for heritage images

The Cultural Heritage (CH) media, which include photographs, audio, and videos, are the valuable asset of a region, state, or even a nation. This not only provides them with information about their ancestors, but also portrays their way of life, artistic approach, and a variety of other historical and archaeological principles. The protection of the heritage media is one of the main concerns in today’s world where cyber-crime is on the rise and unauthorized users can easily access the precious heritage media. For copyright protection of the CH images, this paper presents a robust blind watermarking algorithm for color images based on Integer Wavelet Transform (IWT). The watermark is embedded in the Cb component of the YCbCr color space. The IWT divides the Cb component into four sub-bands, among those four sub-bands, the LL sub-band being highly robust is selected for embedding the watermark by employing inter pixel-differencing procedure. Arnold transform has also been used to increase the security of the watermark. From the experimental results, it is evident that the proposed scheme is highly robust to various types of singular as well as hybrid attacks. The proposed scheme offers the mean Peak-Signal-to-Noise-Ratio (PSNR) of 46.12dB for 100 cultural images. Also, Normalized Correlation (NC) values are close to 1 which not only shows better robustness of the scheme but also guarantees its imperceptibility.