Digital image watermarking on illumination component

This paper proposes a digital image watermarking method in homomorphic domain. In the proposed method, a homomorphic filter is applied to the host color image to extract a low variational illumination component. This component is used to embed a binary watermark image with the same size as host image. The watermark extraction is achieved by using an original illumination component prediction technique based on linear combination of watermarked component values around the embedded one. The predicted component is subtracted from the watermarked component to obtain the extracted watermark. The performance of the proposed method in terms of average NC is evaluated and compared with the previous work. Its robustness against image processing based attacks at various strengths is also compared.