Image watermarking based on DWT coefficients modification for social networking services

This paper considers a situation where the copyright of distributed images/photos in social networks is violated. Since the images/photos published on social networks are usually modified and/or compressed to the match the template provided by the service providers, we thus propose a digital image watermarking based on DWT coefficients modification to be used for such images/photos. Basically, in the embedding process, the blue component of original host image is decomposed by the Discrete Wavelet Transform (DWT) to obtain the coefficients in LL subband, and some of them are used to carry watermark signal. In the extraction process, original coefficients prediction in the LL sub-band based on mean filter is employed to extract the embedded watermark. The experimental results show that the performance of our proposed method in term of average NC is superior to the previous ones.