Reversible watermark using difference expansion of quads

Abstract

A reversible watermarking algorithm with very high data hiding capacity has been developed for colored images. The algorithm allows the watermarking process to be reversed to restore the original image exactly. The algorithm hides triplets of bits in the difference expansion of quads of adjacent pixels. The necessary difference expansion transform and its inverse is derived for quads. Also, the necessary conditions to avoid under-and overflow are derived. The algorithm can also be applied recursively, to maximize the amount of data that can be hidden into an image. Simulation results show that the algorithm can hide a bit-rate as high as 3.3 bits/colored pixel while maintaining an image quality level of 33.5 dB.

Reversible data hiding exploiting spatial correlation between sub-sampled images

“…The main advantage was high embedding capacity, but disadvantages were undesirable distortion at low capacities and lack of capacity control due to embedding of a location map which contained the location information of all selected expandable difference values. Alattar developed the DE technique for color images using triplets [12] and quads [13] of adjacent pixels and generalized DE for any integer transform [14]. Kamstra and Heijmans [15] improved the DE technique by employing lowpass components to predict which location will be expandable, so their scheme was capable of embedding small capacities at low distortions.…”

Watermarking Capacity Control for Dynamic Payload Embedding

“…Tian [28] pioneered the DE scheme addressing the low capacity and/or noticeable visual artefact problems of earlier feature compression based reversible schemes [2,8,9]. Tian's scheme is later generalised by Alattar [1], and then improved using the sorting of pixel-pairs by Kamstra and Heijmans [12] for higher embedding capacity. Kim et al [13] improved Tian's scheme using the simplified location map to reduce the overhead data.…”

Performance Analysis on Different Images using Reversible Data Hiding Technique and its Application

“…A color image improves hiding capacity and hence gives better PSNR. Reversible data hiding (RDH) has many different techniques such as Difference Expansion method (DE) in [1] and [2], Histogram modification method in [3] and [4], Lossless compression methods in M. [5] and [6].…”