a), b), c), b) Distributed Video Coding Based on Selective Block Encoding Using Feedback of Motion Information Jin-soo Kim a), Jae-Gon Kim b), Kwang-d

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1 a), b), c), b) Distributed Video Coding Based on Selective Block Encoding Using Feedback of Motion nformation Jinsoo Kim a), JaeGon Kim b), Kwangdeok Seo c), and Myeongjin Lee b) (DVC: Distributed Video Coding).,,.,,.. ABSTRACT Recently, DVC (Distributed Video Coding) techniques are drawing a lot of interests as one of the future research works to achieve low complexity encoding in various applications. But, due to the limited computational complexity, the performances of DVC algorithms are inferior to those of conventional international standard video coders, which use zigzag scan, run length code, entropy code and skipped macroblock. n this paper, in order to overcome the performance limit of the DVC system, the distortion for every block is estimated when side information is found at the decoder and then we propose a new selective block encoding scheme which provides the encoder side with the motion information for the highly distorted blocks and then allows the sender to encode the motion compensated frame difference signal. Through computer simulations, it is shown that the coding efficiency of the proposed scheme reaches almost that of the conventional interframe coding scheme. Keywords: DVC, Selective Encoding, WynerZiv a) School of nformation Communications and Computer Engineering, Hanbat National University b) School of Electronics, Telecommunication & Computer Engineering, Korea Aerospace University c) Computer & Telecommunications Engineering Division, Yonsei University : (jgkim@kau.ac.kr) T (NPA2010(C )) GRRC [GRRC 2010B02]. ( ),( ), ( )

2 . 5 ~ 10. VoD, (down link).,,, PC. (up link),. (DVC: Distributed Video Coding) [1][2].,,,.,.,, [3][4][5][6][7][8][9]. X. Artigas [3],. J. Ascenso [4] WZ (PDWZ: PixelDomain WynerZiv), S. Park [5],. G. Huai [6] WZ, WZ. [7]. [8].,,,., [5] [7]. [5],, [7].., PDWZ,. [7], PDWZ.. V,

3 , RD., V.. PDWZ 1. PDWZ PDWZ. 1 PDWZ. WZ, H.264. WZ, LDPC(Low Density Parity Check). WZ, (S: Side nformation).,, LDPC. WZ. 2. PDWZ 1 PDWZ. [7], [10]. 2 [7],. WZ,. 1. PDWZ Fig. 1. A simple PDWZ structure

4 0, MSB(Most Significant Bit).,,,. MSB,. LDPC. requestanddecode. 1,. 3. PDWZ,,. [5], WZ..,, (bilateral cost)., M, p. (side matching cost). 2. PDWZ [5] Fig. 2. A PDWZ structure with code conversion and gray code

5 , B, p. p. (1) (2)., [5] 50%,,. SAD(Sum of Absolute Difference), SAD b(v) SAD. SAD f(v) SAD b(v) v., SAD m(v). v* (4), [5] J. Ascenso [4].,., [9]. (v*). v * = arg min[ SAD ( v) + SAD ( v) + SAD f b m v f ( v) = å Î + + p M p) p v SAD b ( v) = å Î + p M p) p v) m ( v) = å Î + + p M p v / 2) p SAD ) ( v)] SAD v / 2), p M. SAD f(v) ˆ ( p) * * p v / 2) + p + v / 2) 2 + = Fig. 3. Blockcentered motion estimation 2. [5], LDPC. [5]

6 4. PDWZ Fig. 4. A PDWZ codec structure with the feedback of motion information,. 4 WZ. 5 PDWZ., i (4) (5), i (1)(3)... (T).,..,.,. 5. PDWZ Fig. 5. Flow chart for the control of the proposed PDWZ decoder

7 V. Discover [2], QCF 30Hz Foreman, Salesman, Coast, Hall Soccer., H.264,. 1. [7] [10]. [7] [10]. Foreman Salesman 101,. 6 Foreman 25, MSB (BP1) MSB3 (BP3)., (a) BP1 (b) BP2 (c) BP3 (d) BP4 6. Foreman Fig. 6. Comparison of virtual channel noises per bitplane for Foreman sequence

8 ., MSB MSB1. 7 Salesman 15,.. Salesman Foreman. 2. RD PDWZ RD 50%. RD. PP :, H.264 : H.264 (a) BP1 (b) BP2 (c) BP3 (d) BP4 7. Salesman Fig. 7. Comparison of virtual channel noises per bitplane for Salesman sequence

9 PSNR (db) 40 PP Proposed Discover ChannelDiv ConvPDWZ PSNR (db) PP Proposed Discover ChannelDiv ConvPDWZ bit rate (kbps) (a) Coast (30Hz) bit rate (kbps) (b) Hall (30Hz) PSNR (db) 40 PP Proposed Discover ChannelDiv ConvPDWZ Fig. 8. Simulation results for bitrate vs PSNR bit rate (kbps) (c) Soccer (30Hz) Discover : Discover [2] ConvPDWZ : [5], PDWZ ChannelDiv : [5], % PDWZ Proposed : 3.1, % PDWZ 8 Discover 3. Coast,. H.264 (PP). Hall

10 . Soccer H.264. Discover (, ), DPCM VLC. (8x8 ) QCF 50% bps 20kbps.. V..., H.264. PDWZ,..,,. [1] A. Aaron, D. Varodayan and B. Girod, "WynerZiv Residual Coding of Video," in Proc. PCS2006, Beijing, China, April [2] [3] X. Artigas and L. Torres, terative Generation of Motioncompensated side nformation for Distributed Video Coding, in Proceedings of EEE nternational Conference on mage Processing (CP '05), vol. 1, pp , Genova, taly, September [4] J. Ascenso, C. Brites, and F. Pererira, mproving Frame nterpolation with Spatial Motion Smoothing for Pixel Domain Distributed Video Coding, " in Proc. EURASP Conf. Speech and mage Processing, July 2005, pp [5] S.U. Park, J.W. Choi, C.S. Kim, S.U. Lee and J.W. Kang, "Efficient Distributed Video Coding Using Symmetric Motion Estimation and Channel Division", in PACRM09, Aug [6] G. Huai and C. W. Chen, "Distributed Video Coding With Zero Motion Skip and Efficient DCT Coefficient Encoding," CME'08, pp , April [7] J.s. Kim, J.G. Kim, and K.d. Seo, A PDWZ Encoder Using Code Conversion and Bit nterleaver, Jour. of the Broadcasting Engineering, Vol.15, No.1, pp.5262, Jan [8] KY Min, SN Park, JH Nam, DG Sim, SH Kim, Distributed Video Coding based on Adaptive Block Quantization Using Received Motion Vectors, in Jour. of KCS, Vol. 35, No. 2, , Feb

11 [9] J.s. Kim, J.G. Kim, Side nformation Generation Using Variable Block Bilateral Matching for WynerZiv Coding in Proc. PU, Jan [10] Anatrasirichai, D. Agrafiotis, M. Ouaret, F. Dufaux, and T. Ebrahimi, "Performance Evaluation of Two State of the Art DVC Codecs," Proc. CDSC 2009, Como, taly, Aug : : KAST : KAST ~ : ~ : ~ : :,, : : KAST : KAST ~ : (ETR) / ~ : ~ : : /,,, : KAST : KAST : KAST ~ : LG ~ : :,,, : KAST : KAST : KAST ~ : ( ) System LS ~ : ~ : :,,