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Reversible Image Hiding Scheme Using Predictive Coding and Histogram Shifting. Source: Signal Processing , Vol. 89, Issue 6, June 2009, Pages 1129-1143 Author : Piyu Tsai, Yu-Chen Hu , and Hsui -Lien Yeh Speaker: Hon-Hang Chang Date: 2010.09.14. Outline. Introduction Related Work
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Reversible Image Hiding Scheme Using Predictive Coding and Histogram Shifting Source: Signal Processing, Vol. 89, Issue 6, June 2009, Pages 1129-1143 Author: Piyu Tsai, Yu-Chen Hu, and Hsui-Lien Yeh Speaker: Hon-Hang Chang Date: 2010.09.14
Outline • Introduction • Related Work • Proposed Method • Experiment Results • Conclusions
Introduction • Reversible data hiding Secret data Secret data Extract Embed Stego-image Original image Original image
Related work • The histogram-based reversible data hiding • Peak value(Embeddable) b= 1, no change b=0, close to zero pixel at 1 b=101100 • In the range from zero value • to peak value Close to zero value at 1 • Out of the range from zero • value to peak value original image No change stego image Peak value: 6 Zero value: 4
Peak value: -3 Proposed method • Linear prediction Basic pixel Zero value: -1 Negative histogram (NH) Peak value: 1 Original image (block size 5 by 5) Zero value: 3 Non-negative histogram (NNH) Residual image
Proposed method(Cont.) • Linear prediction Peak value= 1 Peak value= -3 Zero vale= 3 -1 +1 Zero vale= -1 Non-negative histogram (NNH) Negative histogram (NH) Residual image Embed area
Proposed method(Cont.) • Embedding Rule: b=1, no change (-3 or 1) b=0, the peak pixel close to zero pixel at 1 (-2 or 2) Peak value= 1 Peak value= -3 Zero vale= 3 Zero vale= -1 b= …1 0 1 1 0 0 1 0 1 0 1… Residual image Stego-image Embed area
Proposed method(Cont.) • Extracting 1 or -3 b=1 no change Peak value= 1 Peak value= -3 2 or -2 b=0 return to the peak pixel (1 or -3) Zero vale= 3 Zero vale= -1 NH Stego-image Residual stego-image b= …1 0 1 1 0 0 1 0 1 0 1… NNH The pixel x in the range from zeros value and peak value : Close toward the peak value at 1 The pixel xout of the range from zeros value and peak value : no change Original image (block size 5 by 5)
Proposed method • Overlapping scheme • Peak value(No embed) Close to the zero pixel at 2 Peak value= 1, 0 • Overlap value(Embeddable) Zero vale= 3, 4 b= 1close to zero pixel at 1 b=0, close to zero pixel at 2 • Peak value(Embeddable) b= 1, no change b=0, close to zero pixel at 1 NNH b=1 1 0 0 1 0 1 0 0 0 Residual image Residual image
Experiment results Fig . 1 Testing image ‘‘MRI_400_400’’: (a) original image, (b) original histogram, (c) residual histogram and (d) stego-image.
Experiment results(Cont.) Fig. 2. Relationship between the stego-image quality and the hiding capacities Fig . 1 Testing image ‘‘MRI_400_400’’: (a) original image, (b) original histogram, (c) residual histogram and (d) stego-image.
Conclusions • The proposed method can achieve the goal of higher • hiding capacity. • The secret data are embedded in the residual images • instead of the image histogram.