ABSTRACT
This chapter presents a novel fragile watermark-based reversible image authentication scheme. Fragile digital watermarking is used to accomplish data authentication, and a variety of fragile watermark-based image authentication schemes have been developed. Liu employed permutation transformation and chaotic image patterns to break the corresponding positional relation between pixels in the watermarked image and those in the watermark. Moreover, reversible watermark embedding allows the exact recovery of the original image after the authentication message has been extracted. The chapter introduces the watermarking scheme and also considers a performance analysis. It then provides an improved reversible data-hiding algorithm using multiple scanning techniques and histogram modification. The improved reversible data-hiding algorithm consists of two stages: encoding the payload within an image to produce the cover image and decoding the cover image to retrieve the payload and the original image. The proposed algorithm for optimizing the histogram shift and EL order is an application of the hill-climbing technique.
