摘要：Traditional image authentication methods cannot preserve the authenticity after the processing of the JPEG lossy compression. This is because the JPEG lossy compression destroys the secret embedded in the image. However, the JPEG lossy compression has been so widely used that it simply exists everywhere. Thus, this kind of modification should be taken into consideration. To improve traditional image authentication methods, we shall propose a new method that can not only prevent images from being tampered with but also allow reasonable JPEG lossy compression. Our method works by extracting some significant discrete cosine transform (DCT) coefficients and setting a compression tolerant range. The extracted DCT coefficients will be able to survive when the image is not further modified or lossily compressed. The experimental results show that our method can tolerate JPEG lossy compression while keeping the image from illegal modifications.
