Joint Data Hiding & Source Coding with Partially Available Side Information

Joint Data Hiding & Source Coding with Partially Available Side Information Ç. Dikici, K. Idrissi, A.Baskurt LIRIS, UMR 5205 CNRS INSA de Lyon, France

Agenda • Data Hiding and Distributed Source Coding • System Architecture • Experiments • Conclusion Joint Data Hiding-DSC, SPIE 2006

Motivation • Coding of multiple sources which can not communicate at the encoder • Ultra-low encoding complexity • Reduce power consumption • Data hiding for each source signal Joint Data Hiding-DSC, SPIE 2006

Literature • Wyner-Ziv, Gel'fand-Pinsker • Ramchandran et al, « Duality between source coding and channel coding with SI », Asilomar99, ISIT00, 01 • Girod et al., « Duality between Channel Coding and Rate distortion with SI », Asilomar00 • Cover et al., « Duality Between Channel capacity and Rate distortion with two sided State Information », ITT02 Joint Data Hiding-DSC, SPIE 2006

i(x) i( ) X’( ) X’(i,S2) X S2 Theory(1/3) • Source Coding with SI (R01) Rate Joint Data Hiding-DSC, SPIE 2006

Theory(2/3) • Channel Coding with SI (Blind watermarking or C10) Capacity e W Y Encoder or quantizer Decoder M watermark M’(Y) Z (attack) S1 Joint Data Hiding-DSC, SPIE 2006

Theory(3/3) • Channel Coding with SI (General solution Cgeneral) Capacity W Y e Encoder or quantizer Decoder M watermark M’(Y,S2) Z (attack) S2 S1 Joint Data Hiding-DSC, SPIE 2006

Proposed schema Outter C Inner R01 Receiver Sender coset C CCSI Encoder SCSI Encoder e SCSI Decoder CCSI Decoder W W’ M’ M S1 S2 S1,S2 ~ p(S1,S2) S1,W ~ p(S1,W) Joint Data Hiding-DSC, SPIE 2006

M Data embedder S1 Virt. channel Experimental Setup W • DATA HIDING Embed 2 bits of M within R bits of S1 Using: coset1={000,111} coset2={001,110} coset3={010,101} coset4={100,011} M=3 Slsb=100 =>W=101 • Estimation Final estimate of W` and M` • DECODING Use S2 and P Decode with modified Belief propagation • ENCODING 3/5 LDPC code with H(3500,2000) parity check matrix send only parity bits P • INPUTS S1= 100x2000 bit blocks with Bernoulli(1/2) S2= S1+N where N~ Bernoulli(p) M= Random message W Rate r encoder S2 Decoder W’ M’ Joint Data Hiding-DSC, SPIE 2006

System performance Pe=0 for p<0.13 Channel capacity for rate= 3/5 is pe=0.08 Since errors are only in systematic bits 0.13*3/5 = 0.078 Joint Data Hiding-DSC, SPIE 2006

Conclusions • A DSC system with data hiding • Works well up to a certain correlation to noise ratio • On sensor networks, each client can embed its specific data to the stream • Will be extended to the multimedia data like image, and video Joint Data Hiding-DSC, SPIE 2006

Thank you for your attention Joint Data Hiding-DSC, SPIE 2006

System realization Compression params. Encoder Decoder Output statistics Virtual channel Joint Data Hiding-DSC, SPIE 2006

Joint Data Hiding & Source Coding with Partially Available Side Information