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Proceedings Paper

Efficient requantization method for INTRA MB in heterogeneous transcoding
Author(s): Kwang-deok Seo; Jae-Kyoon Kim; Kook-yeol Yoo; Yoon-Soo Kim
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Paper Abstract

In this paper, we propose an efficient requantization method for INTRA Macroblocks (MB) in heterogeneous transcoding MPEG-1 to MPEG-4 simple profile. The quantizer for MPEG-1 INTRA MB usually uses a quantization matrix while the quantizer for MPEG-4 simple profile doesn't. As a result, the quantization step sizes of the two quantizers may not be the same even for the same quantization parameter. Due to this mismatch in the quantization step size, the transcoded MPEG-4 sequence suffers serious quality degradation and the number of bits produced by transcoding increases from the original MPEG-1 video sequence. To solve these problems, we propose an efficient method to find a near-optimum reconstruction level in the transcoder. We also present a PDF (probability distribution function) estimation model for the original DCT coefficients of MPEG-1 video sequence, which is required for the proposed requantization. Experimental results show that the proposed method gives 0.3 to approximately 0.7 dB improvement in PSNR over the conventional method, even at the reduced bit-rate about 5 to approximately 7% from the conventional method.

Paper Details

Date Published: 29 December 2000
PDF: 11 pages
Proc. SPIE 4310, Visual Communications and Image Processing 2001, (29 December 2000); doi: 10.1117/12.411787
Show Author Affiliations
Kwang-deok Seo, Korea Advanced Institute of Science and Technology (South Korea)
Jae-Kyoon Kim, Korea Advanced Institute of Science and Technology (South Korea)
Kook-yeol Yoo, Samsung Electronics Co., Ltd. (South Korea)
Yoon-Soo Kim, Samsung Electronics Co., Ltd. (South Korea)


Published in SPIE Proceedings Vol. 4310:
Visual Communications and Image Processing 2001
Bernd Girod; Charles A. Bouman; Eckehard G. Steinbach, Editor(s)

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