Aiming at disadvantages of pixel-level temper detection algorithm and block-level temper detection algorithm

a temper detection algorithm based on intersection division is been proposed in this paper.Watermarking is produced according to image for blocks of 2×2pixels and embedded in various blocks two times.These blocks of the first division are intersected with these blocks of the second division.Watermarking is been encrypted by chaotic sequence.Twice temper detections are processed according to various block location.The last detection result is obtained using the twice detection results by stepwise refinement method.Image recovery is pixel-level.In order to enhance recovery image quality

temper area is twice recovered using embedded information in watermarking block after the watermarking block is judged to be reality.The proposed algorithm can reach pixel-level tamper localization precision.Experiment results show that the algorithm has good recovery performance and may resist noise and vector attack.