A novel Frei‐Chen based fragile watermarking method for authentication of an image.

In recent years, the protection of the intellectual property rights of digital media has become a considerable issue. Especially using digital image editing tools has made it very easy and fast to manipulate images. Therefore, manipulation detection of digital images has become a necessity. This article presents a novel Frei‐Chen based self‐embedding fragile watermarking technique implemented to 3×3 blocks for image manipulate detection. The block key and the Frei‐Chen based block feature are calculated from the non‐overlapping image blocks of size 3×3. Exclusive‐OR operations are applied to the Frei‐Chen based block feature and the block key. After, a nine bit block authentication key is generated from the Frei‐Chen based block feature and the block key. Then the generated authentication key is embedded in the least significant bits of each block. Experimental results prove the effectiveness of the proposed method through the detection of the various attacks and obtain the excellent visual quality of watermarked images. Also, the results demonstrate that the proposed method detects all of the manipulated areas plainly. [ABSTRACT FROM AUTHOR]