A tamper localization approach for reversible watermarking based on histogram bin shifting

In this paper, we have proposed a tamper localization approach for histogram bin shifting based reversible watermarking algorithm, where original image can be obtained from the watermarked image without any distortion. The tamper localization approach finds out the tampered region of the image, which is used for the selective rejection of the cover image. General application of reversible watermarking procedure says that the entire image gets rejected at receiver side due to the hash mismatch and authentication failure. By using our approach when the hash mismatch occurs the selected part of the image is rejected. This will reduce the retransmission overhead on the communication channel and limited bandwidth is required due to small subpart of retransmission of the image. We are taking the advantage of the minimum and maximum point of the histogram for embedding purpose. This will increase the embedding capacity. We have embedded the hash into smaller subpart of the image until embedding is possible. This will help us to find out the tampered region at the receiver end while extracting the hash. The case of hash mismatch in cover image which will lead to selective rejection of the cover image.