  Pixel Value Ordering (PVO) holds an impressive property for high fidelity
Reversible Data Hiding (RDH). In this paper, we introduce a dual-PVO (dPVO) for
Prediction Error Expansion(PEE), and thereby develop a new RDH scheme to offer
a better rate-distortion performance. Particularly, we propose to embed in two
phases: forward and backward. In the forward phase, PVO with classic PEE is
applied to every non-overlapping image block of size 1x3. In the backward
phase,minimum-set and maximum-set of pixels are determined from the pixels
predicted in the forward phase. The minimum set only contains the lowest
predicted pixels and the maximum set contains the largest predicted pixels of
each image block. Proposed dPVO withPEE is then applied to both sets, so that
the pixel values of the minimum set are increased and that of the maximum set
are decreased by a unit value. Thereby, the pixels predicted in the forward
embedding can partially be restored to their original values resulting in both
better-embedded image quality and a higher embedding rate. Experimental results
have recorded a promising rate-distortion performance of our scheme with a
significant improvement of embedded image quality at higher embedding rates
compared to the popular and state-of-the-art PVO-based RDHschemes.
