Data embedding scheme for reversible authentication

Abstract

Many watermarking techniques were proposed for medical images. However, virtually all watermarking schemes introduce some small amount of irreversible distortion, making them unsuitable for certain medical and military imaging applications. This has led to considerable recent interest in developing lossless watermarking schemes. We propose such a lossless scheme that fully recovers the original image using a secure key, incurs low computational overhead. An image is divided into a grid of blocks, and the watermark is embedded in the least significant bits of the pixels in that block. The data required for authentication is produced by an XOR operation between binary pseudo-noise sequences and a hash function computed from the image. We compare our scheme to other recently proposed lossless schemes and show that it produces less perceptible image distortion.