Study on Image Distortions and Bit-rate Changes Induced by Watermark based-on $4{\times}4$ DCT of H.264/AVC

H.264/AVC의 $4{\times}4$ DCT기반 워터마크에 따른 영상왜곡과 비트율 변화에 대한 연구

  • Kim, Sung-Min (Department of Electronic Engineering, Dongguk University) ;
  • Won, Chee-Sun (Department of Electronic Engineering, Dongguk University)
  • Published : 2005.09.25

Abstract

There are some problems in directly applying the conventional MPEG bit-stream based watermarking schemes to the bit-stream of a new compression standard, H.264/AVC. In this paper we analyze the effects of the conventional DCT-based watermarking scheme to H.264/AVC, especially in terms of image distortions and bit-rate changes. It turns out that the intra-frame prediction md CAVLC of H.264/AVC with the watermarking worsen the image distortions and bit-rate changes. The experiment results show on average 28.17dB decrease in PSNR and 56.71% increase in bit-rate over all QPs.

지금까지 적용되었던 MPEG(Motion Picture Expert Group)기반의 워터마크(watermark) 기법들은 새로운 압축 표준 H.264/AVC의 달라진 부호화 방식으로 인하여 H.264/AVC에 그대로 적용되기에는 많은 문제점을 가지고 있다. 본 논문에서는 이전의 압축표준에 사용되었던 DCT(Discrete Cosine Transform)기반의 워터마크 기법이 H.264/AVC에 적용 되었을 때 발생 할 수 있는 문제를 분석하였으며, 그 결과를 영상왜곡 및 비트율(bit-rate) 변화의 측면에서 연구 하였다. 기존의 MPEG-2 사용 되었던 DCT기반 워터마크 기법들이 H.264/AVC에 적용되었을 때 H.264/AVC 부호화의 큰 특징인 인트라(intra) 부호화 및 CAVLC(Context Adaptive Variable Length Coding)의 영향으로 인하여 PSNR은 모든 QP(Quantization Parameter)에 대하여 평균 28.17 dB 감소 되었으며, 비트율은 모든 QP에 대하여 평균 56.71 % 증가 하였다.

Keywords

References

  1. F. Hartung, B. Girod, 'Digital Watermarking of MPEG-2 Coded Video in the Bit Stream Domain,' IEEE International Conference on Acoustics, Speech, and Signal Processing, Vol. 4, pp. 21-24, April 1997 https://doi.org/10.1109/ICASSP.1997.595326
  2. D. Simitopoulos, N. V. Boulgouris, 'Compressed domain Video Watermarking of MPEG Streams,' IEEE International Conference on Multimedia and Expo, Vol. 1, pp. 26-29, August 2002 https://doi.org/10.1109/ICME.2002.1035845
  3. J.J. Chae, K. Khee Pang, 'Data Hiding in Video,' Proceedings of International Conference on Info-tech and Info-net, Vol. 2, pp. 791-796, November 2001
  4. M. Alattar, 'Digital Watermarking of Low Bit-Rate Advanced Simple Profile MPEG-4 Compressed Video,' IEEE Transaction on CSVT, Vol. 13, no. 8, pp. 787-800, August 2003 https://doi.org/10.1109/TCSVT.2003.815958
  5. J. Y. Park, J. H. Lim, G. S. Kim, C. S. Won, 'Invertible Semi-fragile Watermarking Algorithm Distinguishing MPEG-2 Compression from Malicious Manipulation,' International Conference on Consumer Electronics, pp. 18-19, June 2002 https://doi.org/10.1109/ICCE.2002.1013909
  6. G. Qiu, P. Marziliano, A. T.S. Ho, 'A Hybrid Watermarking Scheme for H.264/AVC Video,' Proceedings of the 17th International Conference on Pattern Recognition, pp. 23-26, August 2004 https://doi.org/10.1109/ICPR.2004.1333909
  7. T. Wiegand, G. Sullivan, A. Luthra, 'Overview of the H.264/AVC Video Coding Standard,' IEEE Transaction on CSVT, Vol. 4, pp. 560-576, July 2003 https://doi.org/10.1109/TCSVT.2003.815165
  8. E. Richardson, 'H.264 and MPEG-4 Video Compre- ssion,' John Wiley, 2003
  9. T. Wiegand, 'Study of Final Committee Draft of Joint Video Specification (ITU-T Rec, H.264 | ISO/IEC 14496-10 AVC),' pp. 197, December 2002