Watermarking Algorithm Using Sobel Edge Detection

Digital Watermarking is a process of embedding information into a digital signal. The efficiency of the watermarking process depends on the protection of visually significant information. For that we embed the watermark transparently at the edges of digital image where deformation is less identifiable. To identify the edges we used Sobel edge detection algorithm since it is inexpensive in terms of computations and on the other hand, the gradient approximation which it produces is relatively crude, in particular for high frequency variations in the image.