A New Fragile Watermarking based on Distributed Hamming Code

In this paper, a novel fragile watermarking scheme is proposed for both tamper detection and tampered image recovery based on Hamming code. To serve this purpose, the authentication code (check bits) is computed using Hamming code from data bits. In this work, data bits were selected from the five Most Significant Bits (5_MSB) of the pixel values and authentication code is embedded into the three Least Significant Bits (3LSBs) to preserve image quality. Hamming (7,4) has been extended, in this paper, to (8,5) and is used for embedding, error detection and correction. Each instance of coding is applied on eight pixels (one bit per pixel) located in sufficient far parts of the image. Hence, for tampers smaller than a threshold, the recovery can be done perfectly. According to the experimental results, the proposed method achieves better performance in terms of recovering the tampered areas, compared to state-of-the- art.