*Reversible visible watermarking and lossless recovery of original imagesSource: IEEE transactions on circuits and systems for video technology, vol. 16, no. 11, November 2006Authors: Yongjian Hu and Byeungwoo JeonSpeaker: Chia-Chun Wu ()Date: 2007/05/02

*OutlineIntroductionReversible visible watermarkingProposed methodEmbeddingLossless RecoveryExperimental resultsConclusionsOur proposed method

*Introduction (1/2)Generally, a visible watermark is translucently laid on the host image and designed to be irreversible so as to resist unintentional modifications or malicious attacks.

*Introduction (2/2)However, in some potential applications, a visible watermark is first used as a tag or ownership identifier and then needs to be removable.

Example:1. patients images2. remote sensing3. military imagery

*Reversible visible watermarkingEmbedding algorithmHost imageMarked-imageExtraction algorithmHost imageMarked-imagerecoverSKKUSKKUSKKUSKKUUser key (80 bits)User key (80 bits)

*The Proposed method Embedding (1/5)User key (80 bits) = Watermark size (8 bits+8 bits) + Origin position of R (16 bits+16 bits) + Dc size (16 bits) + key bit plane level (3 bits) H=Sc DcW =Binary watermarkS =Pixel sequence composed of one-bit pixels on IkFig. 1. Framework of visible watermark embedding and data hiding.

*The Proposed method Embedding (2/5)RI-RHost Image IWatermarkW

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011001010

*The Proposed method Embedding (3/5)RWRDDc = 010HidingCompression

149146148144142144144146148

011001010

100101011001001010010100100100001000111010010000100100001001001010010100

2114614816141441614620

000101011001001010010100000100000000111010010000000100001001001000010100

111111111

*The Proposed method Embedding (4/5)To find S which satisfy |Dc|=|S|-|Sc|Dc = 010, |Dc| = 3LSB of I-R0S=0,|S|=1, |Sc|=1 X0S=00, |S|=2, |Sc|=2 X0S=000, |S|=3, |Sc|=2 XS=000010101011Sc=001001011|S|=12, |Sc|=9 OPayload: H=Sc DcH=001001011 010

000010101011010010001010011111110110R100001110010010101011010010001011110

000010101011

001001011010

*The Proposed method Embedding (5/5)Rm(I-R)mWatermarked images Im

1481501471461461491461471491481491481501491481481491461501501511521531501481511471491491492114614814714914614514314016141441451401481441421431614620149143150146145148148147146145148149148149149150149148148149146148148147150151153147147146

*The Proposed method Lossless Recovery (1/2)To find Sc which satisfy |Dc|=|S|-|Sc||Dc| = 3LSB of (I-R)mSc=001001011S=000010101011|Sc|=9, |S|=12 ODc= 010

001001011010010010001010011111110110R100001110010010101011010010001011110

001001011

010

000010101011

*The Proposed method Lossless Recovery (2/2)RWDDc = 010ExtractionDecompressionR

149146148144142144144146148

011001010

100101011001001010010100100100001000111010010000100100001001001010010100

111111111

2114614816141441614620

000101011001001010010100000100000000111010010000000100001001001000010100

*Experimental results (1/2)Fig. 2. Visibly watermarked images with the MSB plane of R as RD (upper row) and the second MSB plane of R as RD (lower row), respectively.

*Experimental results (2/2)TABLE I: Performance evaluation. The unit of |D|; |Dc|; and |S| is Bytes. NRD and Nkb denote the bit plane level of RD and the key bit plane, respectively. The PSNR is calculated without R. (Unit: DB)

*ConclusionsDesign for binary watermarks

The first work that implements a reversible visible watermarking system.

*Our proposed method-embedding (1/2)Host Image IHistogrampeakzeroa=3b=6WatermarkWRI-RID

11111555552222011133397180444333

11111666662222011133397180555333

0110

1001

9223922552

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*Our proposed method-embedding (2/2)D= 1001Watermarked images ImIa=3b=6

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1111166666229223943322552555433

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User key (80 bits) = Watermark size (8 bits+8 bits) + Origin position of R (16 bits+16 bits) + Dc size (16 bits) + key bit plane level (3 bits) + Hybrid/fixed way of Selection (1 bits) + selection step (4 bits) + n (8 bits).

*