  In this paper, a new reversible image authentication technique with tamper
localization based on watermarking in integer wavelet transform is proposed. If
the image authenticity is verified, then the distortion due to embedding the
watermark can be completely removed from the watermarked image. If the image is
tampered, then the tampering positions can also be localized. Two layers of
watermarking are used. The first layer embedded in spatial domain verifies
authenticity and the second layer embedded in transform domain provides
reversibility. This technique utilizes selective LSB embedding and histogram
characteristics of the difference images of the wavelet coefficients and
modifies pixel values slightly to embed the watermark. Experimental results
demonstrate that the proposed scheme can detect any modifications of the
watermarked image.
