New semi-fragile watermarking for JPEG image authentication
一种新的JPEG图像认证半脆弱水印算法

This paper presented a watermarking scheme for JPEG image authentication.The watermark was generated based on the relative sign and magnitudes of Discrete Cosine Transform(DCT) coefficients which were invariant due to an important property of JPEG compression.Combined with an effective method to include all the coefficients either explicit or implicit,the proposed algorithm improved its security level against malicious attacks in transform domain,without embedding more watermarking information in the original image.At the same time,an identification of false tampered blocks in the proposed authentication algorithm improved the accuracy of locating tampered areas.Analysis and experimental results are provided to demonstrate that the watermarked image possesses good perceptual transparence,and that the proposed algorithm takes JPEG compression as an acceptable manipulation.Meanwhile,it is sensitive to other malicious attacks and can locate the tampered areas.