Rotation Scale Invariant Semi Blind Biometric Watermarking Technique for Colour Image

This paper presents a rotation scale invariant digital color image watermarking technique using Scale Invariant Feature Transform (SIFT) which is invariant to geometric transformation. The image descriptors extracted using SIFT transform of original image and watermarked image are used for estimating the scaling factor and angle of rotation of attacked image. Using estimated factors attacked image is then restored to its original size for synchronization purpose. As a result of synchronization, watermark detection is done correctly. In proposed approach the offline signature, which is a biometric characteristics of owner is embedded in second level detailed coefficients of discrete wavelet transform of cover image. The simulation results show that the algorithm is robust against signal processing and geometric attack. Index Terms — Biometric watermarking, Bi-Orthogonal wavelet , geometric attacks, SIFT