La presente invention concerne un procede de codage/decodage d'un vecteur de mouvement et un ... more La presente invention concerne un procede de codage/decodage d'un vecteur de mouvement et un appareil a cet effet. Ce procede comprend les etapes suivantes : selection d'un ensemble de vecteurs de mouvement candidats pour un vecteur de mouvement courant, selection d'un vecteur de mouvement de prediction a partir de l'ensemble de vecteurs de mouvement candidats, et evaluation permettant de savoir si le vecteur de mouvement de prediction peut ou non etre predit dans un appareil de decodage. Si le vecteur de mouvement de prediction peut etre predit, le vecteur de mouvement courants est code au moyen d'un mode de prediction de vecteur de mouvement qui indique un vecteur de mouvement de prediction et une possibilite de prediction. Si le vecteur de mouvement de prediction ne peut etre predit, le vecteur courant est code au moyen d'un mode de prediction de vecteur de mouvement qui indique un vecteur de mouvement de prediction par defaut et une impossibilite de predi...
2009 IEEE International Symposium on Broadband Multimedia Systems and Broadcasting, 2009
The H.264/AVC standard employs the predictive motion vector coding technique using the median pre... more The H.264/AVC standard employs the predictive motion vector coding technique using the median predictor of spatially neighboring three motion vectors. Although the median is effective in reducing redundancy, it is not always optimal in minimizing bits. To solve the matter, a new motion vector coding scheme, known as, MV competition in which decoder is signaled on the selected optimal PMV, has been reported. Though it can use the optimal PMV(Predicted Motion Vector), the bits consumed to indicating the optimal PMV to the decoder increases bit-rate. In this paper, we propose a new motion vector coding scheme that allows usage of an optimal PMV without consuming additional bits to inform the choice of PMV to decoder. Simulation results show that the proposed method gains in BDBR by 3.22% on average, and in BDPSNR by 0.13 dB compared to the H.264/AVC.
2013 IEEE International Conference on Image Processing, 2013
Scalability in video coding is an effective functionality to serve various video contents at diff... more Scalability in video coding is an effective functionality to serve various video contents at different levels of resolution and quality. Based on the High Efficiency Video Coding (HEVC) standard which achieves superior compression performance compared to the H.264/AVC, this paper proposes a new scalable coding method with a coding unit (CU) structure prediction technique for HEVC-based quality scalability. The CU structure in enhancement layer (EL) is differentially encoded using that of the basement layer (BL) as a predictor. The binary values describing the CU structure of BL are operated exclusive-OR (XOR) with those in EL at each CU depth and position. Compared to the simulcast coding, simulation without having any residual prediction technique verifies that the proposed method gains in bit-saving by 0.4% on average.
ABSTRACT In order to achieve high computational performance and low power consumption, modern mic... more ABSTRACT In order to achieve high computational performance and low power consumption, modern microprocessors are usually equipped with special multimedia instructions, multi-threading, and/or multi-core processing capabilities. Therefore, ...
A new motion vector coding method with optimal predictive motion vector selection is proposed. To... more A new motion vector coding method with optimal predictive motion vector selection is proposed. To improve compression performance, the proposed encoder selects an optimal predictive motion vector that produces minimum bits for motion vector coding. The proposed decoder estimates the optimal predictive motion vector without additional information for indicating which predictor is to be used at the encoder side. Experimental results show that compared to the H.264/AVC standard, the proposed scheme improves coding efficiency for various video sequences.
This paper proposes a motion vector coding scheme which uses the optimal predictive motion vector... more This paper proposes a motion vector coding scheme which uses the optimal predictive motion vector from the surrounding causal motion vectors in the minimum ratedistortion sense. The signaling overhead for the selected predictive motion vector is reduced by a contradiction testing that operates under a predefined criterion at both encoder and decoder for pruning the candidate predictive motion vectors. C 2011 Society of Photo-Optical Instrumentation Engineers (SPIE).
Proceedings of the Korean Society of Broadcast Engineers Conference, 2008
The H.264/AVC standard employs the predictive motion vector coding technique using the median pre... more The H.264/AVC standard employs the predictive motion vector coding technique using the median predictor of spatially neighboring three motion vectors. Although the median is effective in reducing redundancy, it is not always optimal in minimizing bits. To solve the matter, a new motion vector coding scheme, known as, MV competition in which decoder is signaled on the selected optimal PMV, has been reported. Though it can use the optimal PMV(Predicted Motion Vector), the bits consumed to indicating the optimal PMV to the decoder increases bit-rate. In this paper, we propose a new motion vector coding scheme that allows usage of an optimal PMV without consuming additional bits to inform the choice of PMV to decoder. Simulation results show that the proposed method gains in BDBR by 3.22% on average, and in BDPSNR by 0.13 dB compared to the H.264/AVC.
The demand of real-time yet high quality video encoding for portable multimedia devices is increa... more 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. Index Terms-H.264/AVC, intra prediction, low complexity, low complexity video encoding, most probable mode, motion vector coding, pooled coding.
The H.264/AVC deblocking filter pays little attention to intracoded blocks. We enhance this filte... more The H.264/AVC deblocking filter pays little attention to intracoded blocks. We enhance this filter by extending it to use intraprediction mode information in its adaptive application to the intracoded block. Experiments show its higher coding efficiency, with blocking artifacts sufficiently minimized in intracoded blocks.
Battery-powered devices has recently become a prevalent platform for which video compression is o... more Battery-powered devices has recently become a prevalent platform for which video compression is one of the most important enabling technologies. The H.264/AVC employs many advanced coding tools for high coding efficiency, however, it requires high computational complexity and high energy consumption. It is a major problem in batterypowered devices. In this paper, we analyze power consumption charactersitic of H.264/AVC video encoding tools using the modified simpleScalar and the Sim- Panalyzer.
The conventional video compression standard of H.264 uses four different prediction modes in B pi... more The conventional video compression standard of H.264 uses four different prediction modes in B pictures, namely, forward, backward, direct, and bi-predictive predictions. The bi-directional prediction mode is a special case of the bi-prediction which employs two reference frames, one from the forward and the other from the backward pictures. The recent Audio-Video Standard (AVS) of China employed a new bi-prediction mode, namely, the symmetric mode under which only a single forward motion vector is coded. The missing backward motion vector is derived from the forward motion vector using temporal distance between forward/backward reference frames to and from the current B picture. However, the technique has a limit in that it can only take advantage of forward motion vector even though the accuracy of forward prediction may be worse than that of the backward one. In this paper, we propose an improved symmetric mode by exploiting not only the symmetric mode with forward motion vector ...
In this paper, a simple motion vector decision method is addressed to reduce the complexity of th... more In this paper, a simple motion vector decision method is addressed to reduce the complexity of the motion estimation in the high efficiency video coding (HEVC). Its basic idea is to inherit the motion vector of a parent for its remaining 2nd partition if the motion information of the 1st partition dividing its parent 2Nx2N PU is identical with that of its parent 2Nx2N PU. Furthermore, this concept is extended to coding unit (CU) depth decision. Experimental results show that the proposed method achieves on average 6.1% of total encoding time saving with only 0.5% BDBR loss under a random access condition, and 6.6% of total encoding time saving with 0.4% BDBR loss under a low delay condition.
In this paper, we proposed a novel method for virtual reality (VR) sickness reduction based on dy... more In this paper, we proposed a novel method for virtual reality (VR) sickness reduction based on dynamic field of view (FOV) processing. Dynamic FOV processing is performed based on the estimated VR sickness for each video frame. The level of sickness is estimated using VR sickness model, which is obtained by defining the relationship between the motion information and the measured VR sickness. For motion information analysis, subregion-based correspondence points tracking is used to efficiently remove outliers and prevent prediction error propagation. Amount of head dispersion is used as a quantitative VR sickness measure, which can be calculated from inertial measurement unit sensor in VR devices. The optimal FOV range was determined by experimentally validating a minimum FOV that can effectively reduce VR sickness with almost negligible loss in presence. The simulation results show a significant decrease of 37% compared to full FOV viewing, when FOV is dynamically varied between fu...
This paper proposes an improved design of an interleaved motion vector coding scheme with flexibi... more This paper proposes an improved design of an interleaved motion vector coding scheme with flexibility in predictive motion vector component by exploiting motion characteristics. It can use component-wise adaptive motion vector predictor based on the utility of spatial and temporal motion field without any signaling bit for indicating decoder of the selected predictive motion vector component. Experiment with test video data shows about 1.99% (max 8.71%) bit rate reduction compared to the conventional H.264/AVC method.
Journal of the Institute of Electronics and Information Engineers
Although most current video coding standards set a fixed motion vector resolution like quarter-pe... more Although most current video coding standards set a fixed motion vector resolution like quarter-pel accuracy, a scheme supporting multiple motion vector resolutions can improve the coding efficiency of video since it can allow to use just required motion vector accuracy depending on the video content and at the same time to generate more accurate motion predictor. However, the selected motion vector resolution for each motion vector is a signaling overhead. This paper proposes a contradiction testing-based signaling scheme of the motion vector resolution. The proposed method selects a best resolution for each motion vector among multiple candidates in such a way to produce the minimum amount of coded bits for the motion vector. The signaling overhead is reduced by contradiction testing that operates under a predefined criterion at both encoder and decoder with a purpose of pruning irrelevant candidate motion vector resolutions from signaling responsibility. Experimental results verified that the proposed scheme is effective in reducing coded motion information by achieving its Bjøntegaard delta bit rate (BDBR) gain of about 4.01% on average (and up to 15.17%) compared to the conventional scheme with a fixed motion vector resolution.
This papers proposes a motion vector coding method which selects the optimal predictive motion ve... more This papers proposes a motion vector coding method which selects the optimal predictive motion vector after excluding some candidate predictive motion vectors in the minimum rate-distortion sense, and prunes the candidate predictive motion vectors by a contradiction testing that operates under a predefined criterion at both encoder and decoder for reducing the signaling information. Experimental results show that the proposed method gains in BDBR by up to 1.8% compared to the H.264/AVC.
La presente invention concerne un procede de codage/decodage d'un vecteur de mouvement et un ... more La presente invention concerne un procede de codage/decodage d'un vecteur de mouvement et un appareil a cet effet. Ce procede comprend les etapes suivantes : selection d'un ensemble de vecteurs de mouvement candidats pour un vecteur de mouvement courant, selection d'un vecteur de mouvement de prediction a partir de l'ensemble de vecteurs de mouvement candidats, et evaluation permettant de savoir si le vecteur de mouvement de prediction peut ou non etre predit dans un appareil de decodage. Si le vecteur de mouvement de prediction peut etre predit, le vecteur de mouvement courants est code au moyen d'un mode de prediction de vecteur de mouvement qui indique un vecteur de mouvement de prediction et une possibilite de prediction. Si le vecteur de mouvement de prediction ne peut etre predit, le vecteur courant est code au moyen d'un mode de prediction de vecteur de mouvement qui indique un vecteur de mouvement de prediction par defaut et une impossibilite de predi...
2009 IEEE International Symposium on Broadband Multimedia Systems and Broadcasting, 2009
The H.264/AVC standard employs the predictive motion vector coding technique using the median pre... more The H.264/AVC standard employs the predictive motion vector coding technique using the median predictor of spatially neighboring three motion vectors. Although the median is effective in reducing redundancy, it is not always optimal in minimizing bits. To solve the matter, a new motion vector coding scheme, known as, MV competition in which decoder is signaled on the selected optimal PMV, has been reported. Though it can use the optimal PMV(Predicted Motion Vector), the bits consumed to indicating the optimal PMV to the decoder increases bit-rate. In this paper, we propose a new motion vector coding scheme that allows usage of an optimal PMV without consuming additional bits to inform the choice of PMV to decoder. Simulation results show that the proposed method gains in BDBR by 3.22% on average, and in BDPSNR by 0.13 dB compared to the H.264/AVC.
2013 IEEE International Conference on Image Processing, 2013
Scalability in video coding is an effective functionality to serve various video contents at diff... more Scalability in video coding is an effective functionality to serve various video contents at different levels of resolution and quality. Based on the High Efficiency Video Coding (HEVC) standard which achieves superior compression performance compared to the H.264/AVC, this paper proposes a new scalable coding method with a coding unit (CU) structure prediction technique for HEVC-based quality scalability. The CU structure in enhancement layer (EL) is differentially encoded using that of the basement layer (BL) as a predictor. The binary values describing the CU structure of BL are operated exclusive-OR (XOR) with those in EL at each CU depth and position. Compared to the simulcast coding, simulation without having any residual prediction technique verifies that the proposed method gains in bit-saving by 0.4% on average.
ABSTRACT In order to achieve high computational performance and low power consumption, modern mic... more ABSTRACT In order to achieve high computational performance and low power consumption, modern microprocessors are usually equipped with special multimedia instructions, multi-threading, and/or multi-core processing capabilities. Therefore, ...
A new motion vector coding method with optimal predictive motion vector selection is proposed. To... more A new motion vector coding method with optimal predictive motion vector selection is proposed. To improve compression performance, the proposed encoder selects an optimal predictive motion vector that produces minimum bits for motion vector coding. The proposed decoder estimates the optimal predictive motion vector without additional information for indicating which predictor is to be used at the encoder side. Experimental results show that compared to the H.264/AVC standard, the proposed scheme improves coding efficiency for various video sequences.
This paper proposes a motion vector coding scheme which uses the optimal predictive motion vector... more This paper proposes a motion vector coding scheme which uses the optimal predictive motion vector from the surrounding causal motion vectors in the minimum ratedistortion sense. The signaling overhead for the selected predictive motion vector is reduced by a contradiction testing that operates under a predefined criterion at both encoder and decoder for pruning the candidate predictive motion vectors. C 2011 Society of Photo-Optical Instrumentation Engineers (SPIE).
Proceedings of the Korean Society of Broadcast Engineers Conference, 2008
The H.264/AVC standard employs the predictive motion vector coding technique using the median pre... more The H.264/AVC standard employs the predictive motion vector coding technique using the median predictor of spatially neighboring three motion vectors. Although the median is effective in reducing redundancy, it is not always optimal in minimizing bits. To solve the matter, a new motion vector coding scheme, known as, MV competition in which decoder is signaled on the selected optimal PMV, has been reported. Though it can use the optimal PMV(Predicted Motion Vector), the bits consumed to indicating the optimal PMV to the decoder increases bit-rate. In this paper, we propose a new motion vector coding scheme that allows usage of an optimal PMV without consuming additional bits to inform the choice of PMV to decoder. Simulation results show that the proposed method gains in BDBR by 3.22% on average, and in BDPSNR by 0.13 dB compared to the H.264/AVC.
The demand of real-time yet high quality video encoding for portable multimedia devices is increa... more 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. Index Terms-H.264/AVC, intra prediction, low complexity, low complexity video encoding, most probable mode, motion vector coding, pooled coding.
The H.264/AVC deblocking filter pays little attention to intracoded blocks. We enhance this filte... more The H.264/AVC deblocking filter pays little attention to intracoded blocks. We enhance this filter by extending it to use intraprediction mode information in its adaptive application to the intracoded block. Experiments show its higher coding efficiency, with blocking artifacts sufficiently minimized in intracoded blocks.
Battery-powered devices has recently become a prevalent platform for which video compression is o... more Battery-powered devices has recently become a prevalent platform for which video compression is one of the most important enabling technologies. The H.264/AVC employs many advanced coding tools for high coding efficiency, however, it requires high computational complexity and high energy consumption. It is a major problem in batterypowered devices. In this paper, we analyze power consumption charactersitic of H.264/AVC video encoding tools using the modified simpleScalar and the Sim- Panalyzer.
The conventional video compression standard of H.264 uses four different prediction modes in B pi... more The conventional video compression standard of H.264 uses four different prediction modes in B pictures, namely, forward, backward, direct, and bi-predictive predictions. The bi-directional prediction mode is a special case of the bi-prediction which employs two reference frames, one from the forward and the other from the backward pictures. The recent Audio-Video Standard (AVS) of China employed a new bi-prediction mode, namely, the symmetric mode under which only a single forward motion vector is coded. The missing backward motion vector is derived from the forward motion vector using temporal distance between forward/backward reference frames to and from the current B picture. However, the technique has a limit in that it can only take advantage of forward motion vector even though the accuracy of forward prediction may be worse than that of the backward one. In this paper, we propose an improved symmetric mode by exploiting not only the symmetric mode with forward motion vector ...
In this paper, a simple motion vector decision method is addressed to reduce the complexity of th... more In this paper, a simple motion vector decision method is addressed to reduce the complexity of the motion estimation in the high efficiency video coding (HEVC). Its basic idea is to inherit the motion vector of a parent for its remaining 2nd partition if the motion information of the 1st partition dividing its parent 2Nx2N PU is identical with that of its parent 2Nx2N PU. Furthermore, this concept is extended to coding unit (CU) depth decision. Experimental results show that the proposed method achieves on average 6.1% of total encoding time saving with only 0.5% BDBR loss under a random access condition, and 6.6% of total encoding time saving with 0.4% BDBR loss under a low delay condition.
In this paper, we proposed a novel method for virtual reality (VR) sickness reduction based on dy... more In this paper, we proposed a novel method for virtual reality (VR) sickness reduction based on dynamic field of view (FOV) processing. Dynamic FOV processing is performed based on the estimated VR sickness for each video frame. The level of sickness is estimated using VR sickness model, which is obtained by defining the relationship between the motion information and the measured VR sickness. For motion information analysis, subregion-based correspondence points tracking is used to efficiently remove outliers and prevent prediction error propagation. Amount of head dispersion is used as a quantitative VR sickness measure, which can be calculated from inertial measurement unit sensor in VR devices. The optimal FOV range was determined by experimentally validating a minimum FOV that can effectively reduce VR sickness with almost negligible loss in presence. The simulation results show a significant decrease of 37% compared to full FOV viewing, when FOV is dynamically varied between fu...
This paper proposes an improved design of an interleaved motion vector coding scheme with flexibi... more This paper proposes an improved design of an interleaved motion vector coding scheme with flexibility in predictive motion vector component by exploiting motion characteristics. It can use component-wise adaptive motion vector predictor based on the utility of spatial and temporal motion field without any signaling bit for indicating decoder of the selected predictive motion vector component. Experiment with test video data shows about 1.99% (max 8.71%) bit rate reduction compared to the conventional H.264/AVC method.
Journal of the Institute of Electronics and Information Engineers
Although most current video coding standards set a fixed motion vector resolution like quarter-pe... more Although most current video coding standards set a fixed motion vector resolution like quarter-pel accuracy, a scheme supporting multiple motion vector resolutions can improve the coding efficiency of video since it can allow to use just required motion vector accuracy depending on the video content and at the same time to generate more accurate motion predictor. However, the selected motion vector resolution for each motion vector is a signaling overhead. This paper proposes a contradiction testing-based signaling scheme of the motion vector resolution. The proposed method selects a best resolution for each motion vector among multiple candidates in such a way to produce the minimum amount of coded bits for the motion vector. The signaling overhead is reduced by contradiction testing that operates under a predefined criterion at both encoder and decoder with a purpose of pruning irrelevant candidate motion vector resolutions from signaling responsibility. Experimental results verified that the proposed scheme is effective in reducing coded motion information by achieving its Bjøntegaard delta bit rate (BDBR) gain of about 4.01% on average (and up to 15.17%) compared to the conventional scheme with a fixed motion vector resolution.
This papers proposes a motion vector coding method which selects the optimal predictive motion ve... more This papers proposes a motion vector coding method which selects the optimal predictive motion vector after excluding some candidate predictive motion vectors in the minimum rate-distortion sense, and prunes the candidate predictive motion vectors by a contradiction testing that operates under a predefined criterion at both encoder and decoder for reducing the signaling information. Experimental results show that the proposed method gains in BDBR by up to 1.8% compared to the H.264/AVC.
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Papers by Kwanghyun Won