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Conference on Image and Video Communications and Processing 2005

作者： Wu, YJ Woods, JW Rensselaer Polytech Inst Troy NY 12180 USA

ISBN: (纸本)0819456586

In the scalable video coder MC-EZBC,(1) the scalability for motion vectors was not provided, and this greatly impacts its performance when scaling down to very low bit rates and resolutions. Here we enhance MC-EZBC with scalable motion vector coding using the Context based Adaptive Binary Arithmetic Coder (CABAC).(2) Both a layered structure for motion vector coding and an alphabet general partition (AGP)(3) of the motion vector symbols are employed for SNR and resolution scalability of the motion vector bitstream. With these two new features and the careful arrangement of the motion vector bitstream output from the existing MC-EZBC, we obtain temporal, SNR, and resolution scalability for motion vectors. This significantly improves both visual and objective performance at low bit rates and resolutions with only a slight PSNR loss (about 0.05 dB), but no detectable visual loss, at high bit rates.

关键词： scalable video coding motion vector coding MC-EZBC CABAC

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H.264/AVC IMPROVEMENT BASED ON ADAPTIVE motion vector coding

H.264/AVC IMPROVEMENT BASED ON ADAPTIVE MOTION VECTOR CODING

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Picture coding Symposium 2009

作者： Takahashi, Masashi Yamaguchi, Muneaki Hitachi Ltd Embedded Syst Platform Lab Totsuka Ku Yokohama Kanagawa 2440817 Japan

ISBN: (纸本)9781424445936

We propose a new method for improving motion vector coding. The coding efficiency of the H.264/AVC standard is significantly degraded for video sequences that include irregular motions. The degradation is caused by the fact that the correlations among the motion vectors on adjacent blocks get to be small when motions are irregular. Our method solves this problem by two schemes. First, the predictive motion vector (PMV) is adaptively coded with additional bits based on the distribution pattern of reference vectors. Second, an appropriate code table for the motion vector difference (MVD) is adaptively selected out of a couple of tables defined in advance. These schemes enable the appropriate methodologies for the motion vector coding to be adaptively selected according to the motion vector diversity. Experimental results show the effectiveness and potentiality of our approach for high coding efficiency.

关键词： motion vector coding motion vector predictor variable length coding H.264/AVC

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An efficient motion vector coding scheme based on minimum bitrate prediction

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IEEE TRANSACTIONS ON IMAGE PROCESSING 1999年第8期8卷 1117-1120页

作者： Kim, SD Ra, JB Korea Adv Inst Sci & Technol Dept Elect Engn Taejon South Korea

motion vector coding efficiency is becoming an important issue in low bitrate video coding because of its increasing relative bit portion. This work presents a new motion vector coding technique based on minimum bitrate prediction. In the proposed scheme, a predicted motion vector is chosen from the three causal neighboring motion vectors so that it can produce a minimum bitrate in motion vector difference coding, Then the prediction error, or motion vector difference (MVD), and the mode information (MODE) for determining the predicted motion vector at a decoder are coded and transmitted in order. Sending bits for MVD ahead of bits for the MODE, the scheme can minimize the bit amount for the MODE by taking advantage of the fact that the minimum bitrate predictor is used for motion vector prediction. Adaptively combining this minimum bitrate prediction scheme with the conventional model-based prediction scheme, more efficient motion vector coding can be achieved. The proposed scheme improves coding efficiency noticeably for various video sequences.

关键词： low bitrate video coding minimum bitrate prediction motion vector coding

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Adaptive quarter-pel motion estimation and motion vector coding algorithm for the H.264/AVC standard

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OPTICAL ENGINEERING 2009年第11期48卷 110502-110502页

作者： Jung, Seung-Won Park, Chun-Su Ha, Le Thanh Ko, Sung-Jea Korea Univ Dept Elect Engn Seoul 136701 South Korea

We present an adaptive quarter-pel (Qpel) motion estimation (ME) method for H.264/AVC. Instead of applying Qpel ME to all macroblocks (MBs), the proposed method selectively performs Qpel ME in an MB level. In order to reduce the bit rate, we also propose a motion vector (MV) encoding technique that adaptively selects a different variable length coding (VLC) table according to the accuracy of the MV. Experimental results show that the proposed method can achieve about 3% average bit rate reduction. (C) 2009 Society of Photo-Optical Instrumentation Engineers. [DOI: 10.1117/1.3257262]

关键词： motion estimation motion vector coding linear classification

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RD Optimized coding for motion vector Predictor Selection

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IEEE TRANSACTIONS ON CIRCUITS AND SYSTEMS FOR VIDEO TECHNOLOGY 2008年第9期18卷 1247-1257页

作者： Laroche, Guillaume Jung, Joel Pesquet-Popescu, Beatrice ENST Paris F-75634 Paris France France Telecom R&D F-92794 Issy Les Moulineaux France

The H.264/MPEG4-AVC video coding standard has achieved a higher coding efficiency compared to its predecessors. The significant bitrate reduction is mainly obtained by efficient motion compensation tools, as variable block sizes, multiple reference frames, 1/4-pel motion accuracy and powerful prediction modes (e.g., SKIP and DIRECT). These tools have contributed to an increased proportion of the motion information in the total bitstream. To achieve the performance required by the future ITU-T challenge, namely to provide a codec with 50% bitrate reduction compared to the current H.264, the reduction of this motion information cost is essential. This paper proposes a competing framework for better motion vector coding and SKIP mode. The predictors for the SKIP mode and the motion vector predictors are optimally selected by a rate-distortion criterion. These methods take advantage from the use of the spatial and the temporal redundancies in the motion vector fields, where the simple spatial median usually fails. An adaptation of the temporal predictors according to the temporal distances between motion vector fields is also described for multiple reference frames and B-slices options. These two combined schemes lead to a systematic bitrate saving on Baseline and High profile, compared to an H.264/MPEG4-AVC standard codec, which reaches up to 45%.

关键词： H.264 competition-based scheme motion vector coding motion vector prediction multiple reference frames RD-criterion SKIP mode spatio-temporal prediction

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Inter-description motion vector redundancy control for scalable multiple description video coding

Inter-description motion vector redundancy control for scala...

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IET Conference on Image Processing (IPR 2012)

作者： Muhammad Majid Charith Abhayaratne Department of Electronic and Electrical Engineering University of Sheffield UK

ISBN: (纸本)9781622762675

The problem of inter-description motion vector redundancy control in scalable multiple description video coding is addressed in this paper. In the motion compensated temporal filtering (MCTF) followed by the multiple description scalar quantization (MDSQ) of texture data approach, the same set of motion vectors are repeated in both descriptions. While this repetition of motion vector data adds extra overhead, they do not contribute to self correcting of errors as in MDSQed texture data during joint decoding. The paper proposes interleaving of motion vector fields between the descriptions and MDSQ of motion vectors to obtain two correlating motion vector fields rather than repeating them. The results show superior performance of MDSQ of motion vectors compared to other approaches.

关键词： Multiple description video coding Scalability motion vector coding Inter-description redundancy motion vector Video coding motion-compensated temporal filtering vector field redundancy Scalability

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HIERARCHICAL VARIABLE BLOCK SIZE motion ESTIMATION TECHNIQUE FOR motion SEQUENCE coding

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OPTICAL ENGINEERING 1994年第8期33卷 2553-2561页

作者： KIM, JW LEE, SU AUTOMAT & SYST RES INST SEOUL 151742SOUTH KOREA

motion-compensated coding, which exploits the temporal redundancies in the moving images, is one of the most popular techniques currently used. Recently, a variable block size (VBS) motion estimation technique has been proposed to improve the performance of the motion-compensated transform coding (MCTC). This technique allows larger blocks to be used when smaller blocks provide little gain, saving the bit rates especially for areas containing more complex motion. However, there have been few efforts to investigate an efficient VBS motion structure for reducing the motion vector coding rates further. Hence, a new VBS motion estimation technique based on a hierarchical structure is proposed that improves the motion vector encoding efficiency and reduces the number of motion vectors to be transmitted as well. Specifically, the gain/cost motion estimation technique with the selective motion prediction is utilized for the topmost level motion vector search, exploiting the redundancies among the neighboring motion vectors. Also, a restricted search with respect to the topmost level motion vector enables more flexible and efficient motion vector encoding for the remaining lower level blocks. Intensive simulations on several moving image sequences show that the MCTC employing the VBS motion estimation provides a performance improvement of 0.7 to 1.0 dB, in terms of peak SNR, compared with the fixed block size motion estimation.

关键词： motion COMPENSATED coding VARIABLE BLOCK SIZE motion ESTIMATION HIERARCHICAL VARIABLE BLOCK SIZE BLOCK MATCHING ALGORITHM motion vector coding

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EFFICIENT coding OF SIDE INFORMATION IN A LOW BITRATE HYBRID IMAGE CODER

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SIGNAL PROCESSING 1990年第1期19卷 61-73页

作者： SCHILLER, H CHAUDHURI, BB Institut für Theoretische Nachrichtentechnik Universität Hannover Appelstrasse 9a 3000 Hannover 1 Fed. Rep. Germany

With a hybrid coding scheme intended for the transmission of video sequences at 64 kbit/s, several ways of reducing side information are investigated. In a first step, a dual blocksize (DB) concept is introduced to improve the coding efficiency of the side information and visual appearance of the transmitted pictures. In a second step, a hierarchical blockmatching algorithm for improved motion estimation is employed and the motion vector components are differentially coded using variable word length (VWL) codes. The interfield correlations between predictor modes as well as spatial correlations between scan lengths are investigated for a more efficient coding of other side information items. Simulation results on CCITT video test sequences are presented. Zusammenfassung Bei einem Hybrid-Codiersystem für eine Übertragung von Videosequenzen bei 64 kbit/s werden verschiedene Verfahren zur Reduktion der Seiteninformationen untersucht. Im ersten Schritt wird die gleichzeitige Verwendung von 2 Blockgrößen eingeführt, was den Umfang der anfallenden Seiteninformation prinzipiell verringert und dadurch die Bildqualität verbessert. Im zweiten Schritt wird ein hierarchisches Blockmatching-Verfahren für verbesserte Bewegungsschätzung verwendet. Die damit gewonnenen Bewegungsvektoren können differentiell Huffman-codiert werden, wodurch sich der Übertragungsaufwand für die Vektor-Seiteninformation ca. halbiert. Für eine effiziente Übertragung der verbleibenden Seiteninformationen werden die Korrelationen der Prädiktor-Betriebsarten aufeinanderfolgender Bilder sowie die örtllichen Korrelationen der EOB-Seiteninformation benachbarter Sub-Blöcke untersucht. Simulationsergebnisse mit CCITT Standard-Testsequenzen werden präsentiert.

关键词： Hybrid image coding 64 kbit/s video transmission dual blocksize side information motion vector coding predictor mode coding EOB coding

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Object Segmentation-Assisted Inter Prediction for Versatile Video coding

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IEEE TRANSACTIONS ON BROADCASTING 2024年第4期70卷 1236-1253页

作者： Li, Zhuoyuan Yuan, Zikun Li, Li Liu, Dong Tang, Xiaohu Wu, Feng Univ Sci & Technol China CAS Key Lab Technol Geospatial Informat Proc & App Hefei 230027 Peoples R China Southwest Jiaotong Univ Informat Secur & Natl Comp Grid Lab Chengdu 610031 Peoples R China

In modern video coding standards, block-based inter prediction is widely adopted, which brings high compression efficiency. However, in natural videos, there are usually multiple moving objects of arbitrary shapes, resulting in complex motion fields that are difficult to represent compactly. This problem has been tackled by more flexible block partitioning methods in the Versatile Video coding (VVC) standard, but the more flexible partitions require more overhead bits to signal and still cannot be made arbitrarily shaped. To address this limitation, we propose an object segmentation-assisted inter prediction method (SAIP), where objects in the reference frames are segmented by some advanced technologies. With a proper indication, the object segmentation mask is translated from the reference frame to the current frame as the arbitrary-shaped partition of different regions without any extra signal. Using the segmentation mask, motion compensation is separately performed for different regions, achieving higher prediction accuracy. The segmentation mask is further used to code the motion vectors of different regions more efficiently. Moreover, the segmentation mask is considered in the joint rate-distortion optimization for motion estimation and partition estimation to derive the motion vector of different regions and partition more accurately. The proposed method is implemented into the VVC reference software, VTM version 12.0. Experimental results show that the proposed method achieves up to 1.98%, 1.14%, 0.79%, and on average 0.82%, 0.49%, 0.37% BD-rate reduction for common test sequences, under the Low-delay P, Low-delay B, and Random Access configurations, respectively.

关键词： motion segmentation Encoding Video coding Accuracy Standards Shape vectors Inter prediction motion compensation motion estimation motion vector coding object segmentation partition estimation video coding VVC

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Pooling-Based Intra Prediction Mode coding for Mobile Video Applications

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IEEE TRANSACTIONS ON BROADCASTING 2011年第3期57卷 685-694页

作者： Jung, Bongsoo Lee, Hoyoung Won, Kwanghyun Jeon, Byeungwoo Samsung Elect Co Ltd Div Mobile Commun Suwon 443742 South Korea Sungkyunkwan Univ Sch Informat & Commun Engn Suwon 440746 South Korea

The demand of real-time yet high quality video encoding for portable multimedia devices is increasingly strong. The state of the art H.264/AVC standard provides much higher coding efficiency than its predecessors. However, its high computational complexity of encoding is not suitable for battery-powered mobile devices. In this paper, we introduce a low complexity video encoding scheme based on new pooled macroblock modes mainly targeted for battery-operated portable devices. Since the motion prediction and intra prediction take most of the computation and thus battery consumption, restriction of prediction block sizes is essential in implementing a low complexity encoder. However, if this is not done carefully, it may result in unacceptable degradation of coding efficiency. The problem is overcome by developing new macroblock coding modes which are computationally trivial but effective in coding efficiency. Experimental results with several well-known video test sequences verify a far better performance of the proposed method against the standard H.264/AVC encoder operated in low-complexity configuration. Also we evaluate how less power consumption the proposed low complexity encoder actually consumes compared to that of the H.264/AVC baseline profile.

关键词： H.264/AVC intra prediction low complexity low complexity video encoding most probable mode motion vector coding pooled coding

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