A new multi watermarking algorithm based on DWT and hash functions for color satellite images

This paper deals with a blind multi watermarking algorithm which embeds robust ownership watermark and fragile authentication information into satellite images to protect the copyright ownership and integrity of the images. The robust watermark is embedded first in the discrete wavelet transform (DWT) and the second hash authentication code is embedded in the spatial domain. The new technique offers high peak signal to noise ratio (PSNR) and similarity structure index measure (SSIM) values. The technique was successfully tested on a variety of satellite images. The fragile watermark is sensitive to any slight tampering and can locate the area of the editing. The robust watermark survived many intentional and non intentional attacks.