The original paper is in English. Non-English content has been machine-translated and may contain typographical errors or mistranslations. ex. Some numerals are expressed as "XNUMX".
Copyrights notice
The original paper is in English. Non-English content has been machine-translated and may contain typographical errors or mistranslations. Copyrights notice
Dalam makalah ini, kami mencadangkan kaedah pengkuantuan semula yang cekap untuk bingkai INTRA dalam transkod MPEG-1/MPEG-4. Pengkuantiti untuk blok MPEG-1 INTRA biasanya menggunakan matriks pemberat pengkuantitian, manakala pengkuantiti untuk profil ringkas MPEG-4 tidak. Akibatnya, saiz langkah pengkuantitian kedua-dua pengkuantiti mungkin tidak sama walaupun untuk parameter pengkuantitian yang sama. Disebabkan oleh ketidakpadanan dalam saiz langkah pengkuantitian ini, jujukan MPEG-4 yang ditranskodkan boleh mengalami kemerosotan kualiti yang serius dan bilangan bit yang dihasilkan oleh transkod meningkat daripada jujukan video MPEG-1 yang asal. Untuk menyelesaikan masalah ini, kaedah yang cekap dicadangkan untuk mengenal pasti tahap pembinaan semula hampir optimum dalam transcoder. Di samping itu, anggaran PDF (fungsi pengedaran kebarangkalian) berasaskan model Laplacian untuk pekali DCT asal daripada aliran bit MPEG-1 input dibentangkan, yang diperlukan untuk pengkuantitian semula yang dicadangkan. Keputusan eksperimen menunjukkan bahawa kaedah yang dicadangkan memberikan peningkatan 0.3-0.7 dB dalam PSNR berbanding kaedah konvensional, walaupun pada kadar bit yang dikurangkan sebanyak 3-7%.
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Salinan
Kwang-Deok SEO, Kook-Yeol YOO, Jae-Kyoon KIM, "Laplacian-Model Based Requantization for INTRA-Frame Transcoding in VOD Application" in IEICE TRANSACTIONS on Communications,
vol. E85-B, no. 10, pp. 2161-2170, October 2002, doi: .
Abstract: In this paper, we propose an efficient requantization method for INTRA-frames in MPEG-1/MPEG-4 transcoding. The quantizer for an MPEG-1 INTRA block usually uses a quantization weighting matrix, while the quantizer for an MPEG-4 simple profile does not. 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, a transcoded MPEG-4 sequence can suffer from serious quality degradation and the number of bits produced by transcoding increases from the original MPEG-1 video sequence. To solve these problems, an efficient method is proposed to identify a near-optimum reconstruction level in the transcoder. In addition, a Laplacian-model based PDF (probability distribution function) estimation for the original DCT coefficients from an input MPEG-1 bitstream is presented, which is required for the proposed requantization. Experimental results show that the proposed method provides a 0.3-0.7 dB improvement in the PSNR over the conventional method, even at a reduced bit-rate of 3-7%.
URL: https://global.ieice.org/en_transactions/communications/10.1587/e85-b_10_2161/_p
Salinan
@ARTICLE{e85-b_10_2161,
author={Kwang-Deok SEO, Kook-Yeol YOO, Jae-Kyoon KIM, },
journal={IEICE TRANSACTIONS on Communications},
title={Laplacian-Model Based Requantization for INTRA-Frame Transcoding in VOD Application},
year={2002},
volume={E85-B},
number={10},
pages={2161-2170},
abstract={In this paper, we propose an efficient requantization method for INTRA-frames in MPEG-1/MPEG-4 transcoding. The quantizer for an MPEG-1 INTRA block usually uses a quantization weighting matrix, while the quantizer for an MPEG-4 simple profile does not. 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, a transcoded MPEG-4 sequence can suffer from serious quality degradation and the number of bits produced by transcoding increases from the original MPEG-1 video sequence. To solve these problems, an efficient method is proposed to identify a near-optimum reconstruction level in the transcoder. In addition, a Laplacian-model based PDF (probability distribution function) estimation for the original DCT coefficients from an input MPEG-1 bitstream is presented, which is required for the proposed requantization. Experimental results show that the proposed method provides a 0.3-0.7 dB improvement in the PSNR over the conventional method, even at a reduced bit-rate of 3-7%.},
keywords={},
doi={},
ISSN={},
month={October},}
Salinan
TY - JOUR
TI - Laplacian-Model Based Requantization for INTRA-Frame Transcoding in VOD Application
T2 - IEICE TRANSACTIONS on Communications
SP - 2161
EP - 2170
AU - Kwang-Deok SEO
AU - Kook-Yeol YOO
AU - Jae-Kyoon KIM
PY - 2002
DO -
JO - IEICE TRANSACTIONS on Communications
SN -
VL - E85-B
IS - 10
JA - IEICE TRANSACTIONS on Communications
Y1 - October 2002
AB - In this paper, we propose an efficient requantization method for INTRA-frames in MPEG-1/MPEG-4 transcoding. The quantizer for an MPEG-1 INTRA block usually uses a quantization weighting matrix, while the quantizer for an MPEG-4 simple profile does not. 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, a transcoded MPEG-4 sequence can suffer from serious quality degradation and the number of bits produced by transcoding increases from the original MPEG-1 video sequence. To solve these problems, an efficient method is proposed to identify a near-optimum reconstruction level in the transcoder. In addition, a Laplacian-model based PDF (probability distribution function) estimation for the original DCT coefficients from an input MPEG-1 bitstream is presented, which is required for the proposed requantization. Experimental results show that the proposed method provides a 0.3-0.7 dB improvement in the PSNR over the conventional method, even at a reduced bit-rate of 3-7%.
ER -