Novel digital image watermarking using Sobel Filter

Using filters in digital image watermarking makes improvement in the criterion of the watermarking. Watermarking in the edges of the images by using the filters such as Sobel filter operates much more improvements in the imperceptibility of the watermarking rather than not using the edge detection embedding. In this paper, the fact that Human Visual System (HVS) is less sensitive to distortion around edges and textured areas of the image compared to distortion in smooth area is exploited. This paper is presented the novel non-blind watermarking by using the Sobel filter in the Discrete Cosine Transform (DCT) domain. Because of existence of noise near edges of images in the Discrete Wavelet Transform (DWT) the results show that embedding in the DCT domain has better imperceptibility rather than DWT domain.