A Region and Data Hiding Based Error Concealment

A Region and Data Hiding Based Error Concealment Scheme for Images Jue Wang and Liang Ji, IEEE Transactions on Consumer Electronics, Volume: 47, Issue: 2, May 2001 , pp. 257 -262 Advisor : Dr. Chang, Chin-Chen Speaker: Chuang, Tsung-Jen Date : 2003/05/20 1

Outline Introduction n Proposed Method n Experiments n Conclusions n 2

Introduction n DCT v. s. DWT 168 20 0 DCT 16 25 1 34 0 0 DWT 3

Image Coding and Data Hiding Process Fragile Watermark SA-DWT Parity bits insertion ROI ROB RDE Coder SA-DWT RDE Coder 4

Embed Watermark 22 20 36 90 168 20 50 168 16 25 70 40 16 25 45 16 56 67 40 34 34 45 52 34 68 20 78 168168 20 33 168 20 20 26 168 8 20 0 8 6 25 1 16 6 25 1 1 34 0 8 34 4 0 0 2 9 20 10 168 6 20 0 0 w(i)=1 -> 6+ 1 0 1 0 Q(f) - 0 2 3 4 5 6 7 w(i)=0 -> No change Ckey(i) 5

Rate-distortion Optimization 1 0 1 1 0 Binary array after transform 1 0 0 1 0 1 1 1 0 0 1 0 Conventional coder 0 1 1 1 0 0 1 0 Embedded coder 1 0 0 1 0 1 1 1 0 0 1 0 Distortion 0 0 0 1 1 1 0 0 1 Bit rate RDE 6

Image Decoding and Error Concealing Process W ckey Q(f) Watermark extraction and authentication RDE decoder No error Embedded data extraction ROI Authentication RDE decoder ROB Error correction Error No error 7

Experiment Environment Image: Lena 512*512 (262144 bits) n Watermark: 10000 bits n Embedded data: 63800 bits(58000 truncated bits and 5800 parity bits) n ROI 36. 3 d. B ROB 31. 4 d. B 8

Error Detection Capability No change 90% quality JPEG 2000 compression 70% quality JPEG 2000 compression EAF value 0 0. 0328 0. 0578 Operation On ROI data 1% ATM cell loss 5% ATM cell loss 10% ATM cell loss EAF value 0. 177 0. 198 0. 253 Operation On ROI data 9

Error Concealment-Data Lose 10 % ROI 17. 1 d. B 5% ROB 20. 2 d. B ROI 32. 6 d. B ROB 28. 9 d. B 10

Error Concealment-Data Tamper PSNR: 23. 7 d. B 11

Conclusions A novel scheme is proposed in DWT domain n Data hiding technique is used to reconstruct the missing data of ROI of images n This scheme can be used for tamper -proof and tamper-correction n 12