Dual Image-Based Watermarking Scheme Using Interpolation

Digital watermarking is commonly used to hide information for confidentiality and copyright protection and to provide data authentication of medical images. This paper represents an algorithm that uses double images, interpolation, and the SHA-512 method to protect digital documents from illegal access. This increases the ability of the watermarked image to hide and limits the alteration of the cover image. The algorithm depends on some significant steps: the image expansion, i.e., a procedure for converting to an image of high-resolution from a image of low-resolution, hiding secret data within the cover image, selection of one image from a dual image by applying a secret key, and selection of watermarked image using the secret key and finally extract the original cover image. This proposed technique is more authentic. The results of this paper define the quality of image of the used techniques outperform the earlier works.