A novel block-based authentication technique for binary images by block pixel rearrangements

A novel block-based binary image authentication technique is proposed. The authentication signals of each 9times9 image block are placed in a selected 3times3 block within the 9times9 block. The authentication signal contains a certain relationship contributed by the standard deviation values of the other eight 3times3 blocks. Authentication signals are generated by rearranging the pixels in the selected 3times3 block. The rearrangement is designed according to a property of inverse halftoning to keep the visual change in the selected block imperceptible. By comparing the arrangement of the block pixels in a suspicious image with the extracted authentication signals, the fidelity and integrity of the image can be verified