Robust image data hiding designed for semi-fragile image authentication

DATA hiding is a promising technique for the purposes of Authentication, Fingerprinting, Security, Data mining, and copyright protection. Among the existing data hiding techniques hidden data cannot be extracted out correctly after compression and other attacks have been applied to the image. This paper uses a watermarking algorithm which embeds robust ownership watermark and ROI based semi-fragile watermarking technique for image tamper detection and recovery. Image is divided into two distinct regions, ROI and ROB. The authentication information is constructed based on ROI content and re-embedded in ROI region. Recovery information is obtained from ROB and embedded back in the same region.. If ROI region is tampered, the tampered areas can be recovered from the information embedded in ROB.