Effective self-embedding watermarking scheme for image tampered detection and localization with recovery capability

• DCT based effective self-recoverable fragile watermarking scheme is presented.
• This scheme has extreme localization and restoration capability.
• The blocking artifacts negligible because of using the small blocks of size 2 × 2.
• Two levels hierarchical tampered detection mechanisms are used for tampered block detection.

This paper presents a Discrete Cosine Transformation (DCT) based effective self-recoverable fragile watermarking scheme. For each 2×22×2 non-overlapping block, two authentication bits, and ten recovery bits are generated from the five most significant bits (MSBs) of pixels. Authentication bits are embedded in the three least significant bits (LSBs) of the block itself while recovery bits are embedded in the three LSBs of the corresponding mapped block. The proposed watermarking scheme is also effective because the authentication of each block is based on two levels hierarchical tampered detection mechanisms. So the detection of tampered block can be ensured with high probability. The experimental results demonstrate that the proposed scheme not only outperforms high-quality restoration effectively, but also removes the blocking artifacts and improves the accuracy of tamper localization due to the use of very small size blocks, smoothing function and two levels tampering detection mechanisms.