Reversible Date Hiding Based on Histogram Modification of pixel Differences IEEE Transactions on circuits and systems for video technology, VOL. 19, NO. 6,JUNE 2009 Wei-Liang Tai, Chia-Ming Yeh, Chin-Chen Chang 報告者 : 許睿中 日期 :6.20
Outline Introductions Proposed Experimental results Conclusions
Introductions Ni et al. proposed ”Reversible data hiding” ◦ While multiple pairs of peak and minimum points can be used for embedding, the pure payload is still a little low. ◦ Multiple pairs of peak and minimum point must be transmitted to the recipient.
Proposed x i-1 : predictive pixel x i : original pixel x d peak 23 y Secret=101 y i =x i +b =2+1 =3
Proposed x i-1 : predictive pixel x i : original pixel x d peak Secret=101 y i =x i -1 =2-1 =1 213 y
Proposed peak
Proposed y 2 x d i =y i -x i-1 =3-2 =1 x i =y i -1 =3-1 =2 2 b=1
Proposed y peak 2 x d i =y i -x i-1 =4-2 =2 x i =y i -1 =4-1 =
Proposed-Binary Tree Structure Binary Tree Structure number of peak point=2 L
Proposed-Prevent Overflow or Underflow
Proposed-Embedding x d Secret=101 y i =x i -2 L =133-4 = L L+1 0 2L2L -2 L Embedding level L=2 y
Proposed-Embedding x d Secret=101 y i =x i +(d i +b) =139+(3+1) = L L+1 0 2L2L -2 L Embedding level L=2 y Secret=
Proposed-Embedding x d Secret=101 y i =x i +2 L =136+4 = L L+1 0 2L2L -2 L Embedding level L=2 y
Proposed-Embedding L L+1 0 2L2L -2 L 2 L+1 -2 L+1
Proposed-Extraction y x i =y i +2 L =128+4 = L L L+1 -2 L+1 Embedding level L=2 x 150 d i =y i -x i-1 = =
Proposed-Extraction y L L L+1 -2 L+1 Embedding level L=2 x 150 d i =y i -x i-1 = = b=
Experimental results
Conclusion In this letter, we have presented an efficient extension of the histogram modification technique by considering the differences between adjacent pixels rather than simple pixel value. One common drawback of virtually all histogram modification techniques is that they must provide a side communication channel for pairs of peak and minimum points. To solve this problem, we introduced a binary tree that predetermines the multiple peak points used to embed messages; thus, the only information the sender and recipient must share is the tree level L.