A Discrete Cosine Transform (DCT) based Watermarking Scheme for Confidence Guarantee Image Transmission

Since all the multimedia products are released via internet so it‟s very important need today to protect the data from malicious attacks. This directs us to look at digital watermarking which intends to protect the copyright information of the users. This paper presents a Discrete Cosine Transform (DCT) based Signature scheme which provides higher resistance to image processing attacks such as speakle noise, rotation, Gaussian, etc. The invasive distribution of digital images and the growing concern on their integrity and originality in need of authenticating corrupted images by transmission. To meet this need, this paper proposes a new technique that is make digital signatures in image robust to image degradations. The DCT is used to improve the security against forgery attacks due to its precise localization properties and excellent multiscale. Several experiments are carried out to test the proposed scheme in terms of Peak Signal to Noise Ratio (PSNR) and Normalized Cross-Correlation (NC).The obtained results confirm that the proposed scheme can achieve good efficiency against transmission errors. It also is very robust to counterfeiting attacks.