Improved PVO-based reversible data hiding

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 databits into the host image • if LM(i)= 1, the overflow/underflow would occur andwe 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. D0,0 = S1,0 – S1,1

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

11. 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.