Exploiting self-embedding fragile watermarking method for image tamper detection and recovery

The increasingly rapid use of digital images makes data security technology become an important issue to ensure the integrity and ownership of the received image. Watermarking technique is a technique that ensures data security including for checking the authenticity of an image. Current developments, not only can test the authenticity of an image, but also can determine the location of damage while fixing it. The method proposed in this paper is through using the block-based technique of self-embedding fragile watermarking, where the watermark is selected from feature images representing the entire image. Four authentication bits and eight recovery bits are generated in each 2x2 non-overlapping block. 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. Our method is efficient as it only uses simple parity check operations and comparison between average intensities as image tamper detection and use the five most significant bits (MSBs) of 2x2 pixels in average for recovery. The experimental results of the tests on cropped images show that the proposed methods allow image recovery with acceptable visual quality better than some of state-of-the-art schemes.