Subrahmanya M V (Under the guidance of Dr . Rao and Dr.Jin-soo Kim)

1. Subrahmanya M V • (Under the guidance of Dr. Rao and Dr.Jin-soo Kim)

2. Contents • WZ encoder • WZ decoder • Motion Estimation • Half-pel motion estimation • Quarter-pel motion estimation • Motion Compensation • WZ Encoder and Decoder Implementation • Results • Future Tasks • References

3. WZ Encoder

4. WZ Encoder • Encoder is simple in complexity • H.264 Intra Key frames • Calculate WZ frame residual • Quantization • LDPCA Encoder • Rate Control • No motion estimation!

5. WZ Decoder [E. Peixoto, R. L. de Queiroz, and D. Mukherjee 2008]

6. WZ Decoder(Contd) • Complex Decoder • Decode H.264 Intra Key frames • Side Information Generation • Estimation of frame to be decoded • Previously decoded frames are used for estimation • Motion estimation is done here • LDPCA Decoder • Theoretically WZ codec can achieve the same efficiency as regular encoder-decoder pair

7. Motion Estimation • Forward ME between key frames • Backward ME between key frames • Derive MVs for WZ frame using Key frame MVS [E. Peixoto, R. L. de Queiroz, and D. Mukherjee 2008]

8. Half-pel motion estimation

9. Half-pel motion estimation(Contd) • 3 half-pixel positions. Interpolation is done using six tap filter[6] • H33 = [F13 + -5 * F23 + 20 * F33 + 20 * F43 + -5 * F53 + F63 + 15] >> 5 • G33 = [F31 + -5 * F32 + 20 * F33 + 20 * F34 + -5 * F35 + F36 + 15] >> 5 • D33 = [H31 + -5 * H32 + 20 * H33 + 20 * H34 + -5 * H35 + H36 + 15] >> 5

10. Quarter-pel motion estimation

11. Quarter-pel motion estimation(Contd) • 12 quarter pel positions • q1 = ( F33 + G33 + 1 ) >> 1 • q2 = ( G33 + F34 + 1 ) >> 1 • q3 = ( F33 + H33 + 1 ) >> 1 • q4 = ( H33 + G33 + 1 ) >> 1 • q5 = (G33 + D33 + 1 ) >> 1 • q6 = ( G33 + H34 + 1 ) >> 1 • q7 = ( H33 + D33 + 1 ) >> 1 • q8 = ( D33 + H34 + 1 ) >> 1 • q9 = ( H33 + F43 + 1 ) >> 1 • q10 = ( H33 + G43 + 1 ) >> 1 • q11 = ( D33 + G43 + 1 ) >> 1 • q12 = ( G43 + H34 + 1 ) >> 1

12. Motion Compensation • Interpolation of pixels based on motion vector • Filters and Interpolation scheme used for sub-pel MC is same as that of ME • Bidirectional motion compensation

13. WZ Encoder and Decoder Implementation • Integrated LDPCA encoder/decoder with JM encoder/decoder • Side information using simple averaging of key frames • Side information using ME • 16x16, 8x8 and 4x4 block size • Full-pel and half-pel • Bi-directional prediction

14. Results

15. Results(PSNR)

16. Future Tasks • Quarter-pel motion estimation and motion compensation • Increase the number of WZ frames between Key frames

17. References • E. Peixoto, R. L. de Queiroz, and D. Mukherjee, “Mobile video communications using a Wyner-Ziv transcoder,” Proc. SPIE 6822, VCIP, 68220R Jan 2008. • A. Aaron, E. Setton and B. Girod, "Towards practical Wyner-Ziv coding of video," Proceedings. 2003 International Conference on Image Processing, 2003. ICIP 2003., vol.3, pp. III-869-872 vol.2, 14-17 Sept. 2003 • K. R. Rao and J. J. Hwang, Techniques and standards for image, video, and audio coding, Prentice Hall PTR, 1996. • Jin-Soo Kim, "Brief overview of Wyner-Ziv CODEC" (Private Communication) • A. Aaron, D. Varodayan, and B. Girod, “Wyner-Ziv residual coding of video,” Proc. International Picture Coding Symposium, Beijing, P. R. China , April 2006. • T. Wiegand and G.J Sullivan, “The H.264/AVC video coding standard”, IEEE SP Magazine, vol. 24, pp. 148-153, March 2007. • G. J. Sullivan, P. Topiwala, and A. Luthra, "The H.264/AVC advanced video coding standard: Overview and introduction to the fidelity range extensions", SPIE Conf. on applications of digital image processing XXVII, vol. 5558, pp. 53-74, Aug. 2004. • S.K. Kwon, A. Tamhankar, and K.R. Rao “Overview of H.264/MPEG-4 Part 10” J. VCIR, Vol. 17, pp. 186-216, April 2006, Special Issue on “Emerging H.264/AVC Video Coding Standard,”.

18. References(Contd) • A. Wyner and J. Ziv, "The rate-distortion function for source coding with side information at the decoder,"  IEEE Trans., Information Theory, vol.22, pp. 1-10, Jan 1976. • D. Varodayan, A. Aaron and B. Girod, "Rate-adaptive distributed source coding using low-density parity-check codes,"  Conference Record of the Thirty-Ninth Asilomar Conference on Signals, Systems and Computers, 2005, vol., pp. 1203-1207, Oct 28 - Nov 1, 2005. • Z. Li and E.J. Delp, "Wyner-Ziv video side estimator: conventional motion search methods revisited," IEEE International Conference on Image Processing, 2005. ICIP 2005, vol.1, pp. I-825-8, 11-14 Sept. 2005. • L. Liu and E. J. Delp, "Wyner-Ziv video coding using LDPC codes," Proceedings of the 7th Nordic Signal Processing Symposium, 2006. NORSIG 2006. •  D. Kubasov, K. Lajnef and C. Guillemot, "A hybrid encoder/decoder rate control for Wyner-Ziv video coding with a feedback channel," IEEE 9th Workshop on Multimedia Signal Processing, 2007. MMSP 2007., vol., pp.251-254, 1-3 Oct. 2007 • C. Brites and F. Pereira, "Encoder rate control for transform domain Wyner-Ziv video coding," IEEE International Conference on Image Processing, 2007. ICIP 2007., vol.2, pp.II -5-II -8, Sept. 16 2007-Oct. 19 2007 • A. Roca, et al, "Rate control algorithm for pixel-domain Wyner-Ziv video coding ," Proc. SPIE 6822, 68221T (2008). • D. Mukherjee, “Optimal parameter choice for Wyner-Ziv coding of Laplacian sources with decoder side information,” HP Labs Technical Report HPL-2007-34, 2007. • Z. Wang, A.C. Bovik, et al, "Image quality assessment: From error visibility to structural similarity," IEEE Trans., Image Processing, vol.13, no. 4, April 2004