An Adaptive Scaling Factor for Multiple Watermarking Scheme

This paper presents an adaptive scaling factor for multiple watermarking scheme. Watermarks are inserted into the red and green channels with lowest variance of the cover image. DCT is applied on each selected block for transforming image pixels to DCT coefficients. This experiment examines DCT coefficients in the middle frequency to obtain adaptive scaling factor for embedding a watermark. The proposed algorithm used the impact of selected DCT coefficients to imperceptibility and robustness for generating adaptive scaling factor. Arnold transform is used to provide additional security and secrecy of the embedded watermark image. The experimental results reported that our scheme achieves higher invisibility performance for multiple watermarks compared to existing schemes.