1. Improved PVO-based reversible data hiding Source: Digital Signal Processing, 2014 Authors: Fei Peng, Xiaolong Li,ng Reporter: Min-Hao Wu

2. Outline Related Work Proposed Scheme Experimental Results Conclusions

3. Related work High-fidelity reversible data hiding scheme based on pixel-value- ordering and prediction-error expansion Signal Processing Xiaolong Li, Jian Li, Bin Li, Bin Yang

4. Data embedding procedure Step1: Divide the host image into k non-overlapped blocks {X1,...,Xk} Step2: The overflow/underflow location map LM is defined in this step. (Location map construction) embed the data bits into the host image if LM(i)= 1, the overflow/underflow would occur and we do nothing if LM(i)= 0, and Xn-1 – X2 >= T, we do nothing if LM(i)= 0, and Xn-1 – X2 < T, will be shifted or expanded to carry data

5. D 0,0 = S 1,0 – S 1,1

7. Take 2 × 2 sized blocks as an example the histogram of PEmax for the Lena image that capacity about 15,000 bits by PVO-based predictor method the bin with PEmax = 1 is usually the histogram peak

9. Experimental results the performance on PSNR is better for a larger block size. larger sized blocks provide lower maximum EC.

10. Experimental results

20. Conclusion based on ordering the pixel values in image block, an effective predictor is proposed for PEE. the flat blocks are priory selected to embed data, which is helpful to improve the embedding performance. This method can achieve a higher PSNR under the same EC.