Rotation invariant image authentication using Haralick features

The image authentication plays a vital role in modern multimedia technology. The existing technique for preserving authentication abided the content only by preserving transformations like scaling, additive noise, gamma correction, brightness adjustments, water marking etc., but it fails to authenticate larger angles rotations. Very few systems had authenticated rotations to a smaller angle which was less than 5o. In existing system, the failure occurred in authenticating large angle rotation is due to the finite divisions of equal sized square block for calculating the local features. In this paper concept of dividing circular blocks with equal area is analyzed for better competency. The Haralick features are mostly calculated for square block. In the proposed system 14 features of Haralick has been grouped to hash code for each circular blocks in sender side. In receiver side, the same procedure is followed to generate hash code and the comparison is carried out to verify the authentication. In addition to scaling, brightness, contrast adjustment, gamma correction etc., the proposed system tolerates rotation even to greater angles up to 360o with better efficiency.