방송공학회논문지 (Journal of Broadcast Engineering)

  • 제10권3호
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  • Pages.270-285
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  • 2005
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  • 1226-7953(pISSN)
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  • 2287-9137(eISSN)
한국방송∙미디어공학회 (The Korean Institute of Broadcast and Media Engineers)
권호 표지

트랜스코더의 해상도 변환 모듈과 움직임 추정 모듈의 공동 최적화

Joint Optimization of the Motion Estimation Module and the Up/Down Scaler in Transcoders television

  • 한종기 (세종대학교 정보통신 공학과) ;
  • 곽상민 (세종대학교 정보통신 공학과) ;
  • 전동산 (ETRI 방송 미디어 연구 그룹) ;
  • 김재곤 (ETRI 방송 미디어 연구 그룹)
  • Han, Jong-Ki (Dept. of Information & Communications Engineering, Sejong University) ;
  • Kwak, Sang-Min (Dept. of Information & Communications Engineering, Sejong University) ;
  • Jun, Dong-San (Electronics and Telecommunications Research Institute Digital Broadcasting Research Division, Broadcasting Media Research Group) ;
  • Kim, Jae-Gon (Electronics and Telecommunications Research Institute Digital Broadcasting Research Division, Broadcasting Media Research Group)
  • 발행 : 2005.09.01
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⟨ 이전 논문 다음 논문 ⟩

초록

해상도 변환모듈과 움직임 예측모듈은 트랜스코더를 이루는 중요한 모듈이다. 본 논문에서는 트랜스코더 시스템의 이 두 가지 모듈을 공동 최적화하는 기법을 제안한다. 제안하는 기법은 먼저 주어진 움직임 벡터에 대해 해상도 변환모듈을 최적화한 후, 최적화된 해상도 변환모듈에 대해 최적의 움직임 벡터를 결정한다. 기존 해상도 변환 기법들은 한 영상에 대해 변환함수를 최적화하여 사용한다. 본 논문에서는 해상도 변환 최적화를 위하여 적응적 3차 회선 변환기를 제안한다 제안된 방법은 3차 회선 변환기의 인자값을 각 매크로블록 단위로 영상의 지역적 특성을 고려하여 적응적으로 조절한다. 움직임 예측모듈에서는 기존의 고속 트랜스코더 알고리듬에서 많이 연구된 움직임 벡터의 재사용 기법을 사용하였다. 입력 영상의 움직임 벡터를 재사용 함으로써 연산량을 줄일 수 있고 이를 기본 움직임 벡터로 사용해 작은 영역에서 재탐색해 움직임벡터를 결정할 경우 전역탐색기법과 거의 동일한 화질의 영상을 얻을 수 있다. 해상도 변환모듈과 움직임 예측모듈의 공동 최적화를 통해서 트랜스코딩된 영상의 화질 열화를 최소화할 수 있는 알고리듬을 제안한다. 실험 결과 본 논문에서 제안하는 공동 최적화 기법이 기존에 연구 되었던 다른 기법에 비해 화질의 열화가 적은 것을 알 수 있었고, 이를 통해 다른 기법과 비교해 해상도 변환으로 인한 정보의 손실이 가장 적음을 알 수 있다.

A joint design scheme is proposed to optimize the up/down scaler and the motion vector estimation module in the transcoder system. The proposed scheme first optimizes the resolution scaler for a fixed motion vector, and then a new motion vector is estimated for the fixed scaler. These two steps are iteratively repeated until they reach a local optimum solution. In the optimization of the scaler, we derive an adaptive version of a cubic convolution interpolator to enlarge or reduce digital images by arbitrary scaling factors. The adaptation is performed at each macroblock of an image. In order to estimate the optimal motion vector, a temporary motion vector is composed from the given motion vectors. Then the motion vector is refined over a narrow search range. It is well-known that this refinement scheme provides the comparable performance compared to the full search method. Simulation results show that a jointly optimized system based on the proposed algorithms outperforms the conventional systems. We can also see that the algorithms exhibit significant improvement in the minimization of information loss compared with other techniques.

키워드

참고문헌

  1. J. Xin, M.-T.Sun, B.-S. Choi, and K.-W. Chun, 'An HDTV-to-SDTV spatial transcoder,' IEEE Trans. on Circuits and Systems for Video Tech., vol. 12, pp. 998-1008, Nov. 2002 https://doi.org/10.1109/TCSVT.2002.805508
  2. M.-J. Chen, M.-C Chu, and C.-W. Pan, 'Efficient motion-estimation algorithm for reduced frame-rate video transcoder,' IEEE Trans. on Circuits and Systems for Video Tech., vol 12, pp. 269-275, April 2002 https://doi.org/10.1109/76.999204
  3. T. Shanabl도 and M. Ghanbari, 'Heterogeneous video transcoding to lower spatio-temporal resolution and different encoding formats,' IEEE Trans. on Multimedia, vol. 2, pp.101-110, June 2000 https://doi.org/10.1109/6046.845014
  4. Bo Shen, I.K. Sethi, and B. Vasudev, 'Adaptive motion vector resampling for compress video downscaling,' IEEE Trans. on Circ. And Syst. for Video Tech., vol. 9, pp.929-936, Sept. 1999 https://doi.org/10.1109/76.785730
  5. J. Youn, M.-T. Sun, and Chia-Wen Lin, 'Motion vector refinement for high performance transcoding,' IEEE Trans. on Multimedia, vol. 1, pp.30-40, Mar. 1999 https://doi.org/10.1109/6046.748169
  6. C.Yim and M.A. Isnardi, 'An efficient method for DCT-domain image resizing with mixed field/frame-mode macroblocks,' IEEE Trans. on Circuits and Systems for Video Tech., vol. 9, pp. 696-700, Aug. 1999 https://doi.org/10.1109/76.780359
  7. J.Song and B-L Yeo, 'A fast algorithm for DCT-domain inverse motion compensation based on shared information in a macroblock,' IEEE Trans. on Circuits and Systems for Video Technology, vol. 10, pp.767-775, Aug. 2000 https://doi.org/10.1109/76.856453
  8. N. Merhav, 'Multiplication-free approximation algorithm for compressed-domain linear operations on images,' IEEE Trans. on Image Processing, vol.8, pp. 247-254, Feb. 1999 https://doi.org/10.1109/83.743858
  9. S. Liu and A. C. Bovik, 'Local bandwidth constrained fast inverse motion compensation for DCT-domain video transcoding,' IEEE Trans. on Circuits and Systems for Video Technology, vol. 12, pp. 309-319, May 2002 https://doi.org/10.1109/TCSVT.2002.1003470
  10. K.-T. Fung, Y.-L. Chan, and W.-C. Siu, 'New architecture for dynamic frame-skipping transcoder,' IEEE Trans. on Image Processing, vol.11, pp.886-900, Aug. 2002 https://doi.org/10.1109/TIP.2002.800890
  11. H. Sun, W.Kwok, and J.W. Zdepski, 'Architecture for MPEG compressed bitstream scaling,' IEEE Trans. on Circ. And Syst. for Video Techno., vol. 6, pp. 191-199, April 1999
  12. C.D.L. Reyes, A.R. Reibman, S.-F.Chang, and J.C.-I. Chuang, 'Error resilience transcoding for video over wireless channels,' IEEE Journal of Selected Area in Commun., vol. 18, pp. 1063-1074, June 2000 https://doi.org/10.1109/49.848256
  13. H. Hwang, 'Interlaced to progressive scan conversion for HD-MAC application,' IEEE Trans. on Consumer Electronics, vol. 38, no. 3, pp. 151-156, Aug. 1992 https://doi.org/10.1109/30.156676
  14. M. Karlsson, P. Pohjala, H. Rantanen, and S. Kalli, 'Evaluation of scanning rate up conversion algorithm; subjective testing of interlaced to progressive conversion,' IEEE Trans. on Consumer Electonics, vol. 38, no. 3, pp. 162-167, Aug. 1992 https://doi.org/10.1109/30.156678
  15. M. H. Lee, J. H. Kim, J. S. Lee, K. K. Ryu, and D. I. Song, 'A new algorithm for interlaced to progressive scan conversion based on directional corrections and its IC design,' IEEE Trans. on Consumer Electronics, vol. 40, no. 2, pp. 119-129, May 1994 https://doi.org/10.1109/30.286406
  16. R. Li, N. K. Chung, K. T. Mo, D. M. Fisher, and V. Wong, 'A flexible display module for DVD and set-up box applications,' IEEE Trans. on Consumer Electornics, vol. 43, no. 3, pp.496-503, Aug. 1997 https://doi.org/10.1109/30.628664
  17. S. S. Rifman. 'Digital Rectification of ERTS Multispectral Imagery,' Proc. Symposium Significant Results Obtained from ERTS-1 (NASA SP-327), I, Sec. B, pp. 1131-1142, 1973
  18. R. Berstein, 'Digital Image Processing of Earth observation sensor data,' IBM J. Res. Devel., vol. 20, pp. 40-57, 1976 https://doi.org/10.1147/rd.201.0040
  19. R. G. Keys, 'Cubic convolution interpolation for digital image processing,' IEEE Trans. Acoustics, Speech, and Signal Processing, vol. 29, pp. 1153-1160, Dec. 1981 https://doi.org/10.1109/TASSP.1981.1163711
  20. S. K. Park and R. A. Schowengerdt, 'Image reconstruction by parametric cubic convolution,' Computer Vision, Graphics, and Image Processing, vol. 23, pp. 258-272, Sept. 1983 https://doi.org/10.1016/0734-189X(83)90026-9
  21. K. W. Simon, 'Digital image reconstruction and resampling of landsat imagery,' Symposium on Machine Processing of Remotely Sensed Data, Purdue University, pp. 3A-1 -3A-11, June 1975
  22. D. G. Luenberger, Optimization by Vector Space Methods, New York, Wiley, 1969
  23. D. G. Luenberger, Linear and nonlinear programming, Addison-Wesley, 1984
  24. W. K. Pratt, Digital image processing, John Wiley & Sons, INC., 1991
  25. M. Unser, A. Aldroubi, and M. Eden, 'Fast B-spline transforms for continuous image representation and interpolation,' IEEE Trans. on Pattern Analysis and Machine Intelligence, vol. 13, pp. 277-285, March 1991 https://doi.org/10.1109/34.75515