నైరూప్య

Watermarking Technique for Self Authentication and Recovery

Augustus P P, David Solomon George

In this paper, an algorithm for invisible watermarking of digital images has been proposed. This scheme provides self authentication and recovery of watermarked image. The tampered regions in an image, if any, are detected and the recovery of those altered regions are facilitated by the proposed scheme. Image authentication is performed in 4×4 sub-block level. Self recovery is accomplished through descriptors, which enable in reconstructing the altered regions with acceptable quality. The descriptor details corresponding to each region are spatially separated from region of impact. Discrete Wavelet Transform (DWT) and Inverse Discrete Wavelet Transform (IDWT) are employed for the transformations within the image for block based retrieval. The proposed algorithm is experimentally verified and the results are presented.