A reversible image authentication scheme based on fragile watermarking in discrete wavelet transform domain

Image authentication technique protects the integrity of images. Many image authentication schemes have been proposed in recent years. However, in these schemes, the image is permanently distorted and cannot be recovered to its original version after image authentication. In this paper, we propose a new, reversible watermarking scheme for image authentication scheme in the DWT domain to achieve high accuracy of tamper detection, and complete reversibility while maintaining high image quality of watermarked images. In the proposed scheme, authentication code is randomly generated and embedded into 2nd DWT low-frequency subbands of each image block. Our experimental results demonstrated that the proposed scheme has ability to resist against different attacks, i.e., different sizes of tampered regions, content tampered attack, and collage attack, with small distortion of the watermarked image. In addition, the proposed scheme achieves reversibility that is quite important to some special fields, i.e., medical images, military images, and fine artwork.