Takeshi Ikenaga

Takeshi Ikenaga
Waseda University | Sōdai · Graduate School of Information, Production and Systems

PhD

About

289
Publications
12,646
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1,869
Citations
Citations since 2017
53 Research Items
397 Citations
2017201820192020202120222023020406080
2017201820192020202120222023020406080
2017201820192020202120222023020406080
2017201820192020202120222023020406080

Publications

Publications (289)
Chapter
3D human pose estimation plays important roles in various human-machine interactive applications, but how to efficiently utilize the joint structural global and local features of human pose in deep-learning-based methods has always been a challenge. In this paper, we propose a parallel structural global and local joint features fusion network based...
Article
Full-text available
Competitive figure skaters perform successful jumps with critical parameters, which are valuable for jump analysis in athlete training. Driven by recent computer vision applications, recovering 3D pose of figure skater to obtain the meaningful variables has become increasingly important. However, conventional works have suffered from getting 3D inf...
Article
High frame rate and ultra-low delay vision system, which can finish reading and processing of 1000fps sequence within 1ms/frame, draws increasing attention in the field of robotics that requires immediate feedback from image process core. Meanwhile, tracking task plays an important role in many computer vision applications. Among various tracking a...
Article
Full-text available
Data Volley is one of the most widely used sports analysis software for professional volleyball statistics analysis. To develop the automatic data volley system, the vision-based game data acquisition is a key technology, which includes the 3D multiple objects tracking, event detection and quality evaluation. This paper combines temporal and spatia...
Article
Measuring object displacement with subpixel-level accuracy is attracting increasing attention in numerous computer-vision-based applications, because of its high potential in compensating for camera resolution. Although ultrahigh-speed measurement is highly desired in many fields, existing researches on subpixel displacement measurement mainly conc...
Article
Detecting straight lines in video plays a fundamental role in camera-based industrial automation. With the increasing demands on production efficiency, detection speed becomes one of the bottlenecks for highly-efficient industrial automation. Because of data dependency and hardware limitation, existing vision systems based on CPU/GPU are unable to...
Article
Human-machine interactive systems show increasing demand for analysing fast moving objects in high-frame-rate videos. Robust foreground detection, which is able to reduce large amount of redundant background data from high-frame-rate video, becomes the essence to achieve ultra-high-speed human-machine interactions. This paper proposes a local spati...
Preprint
Bottom-up based multi-person pose estimation approaches use heatmaps with auxiliary predictions to estimate joint positions and belonging at one time. Recently, various combinations between auxiliary predictions and heatmaps have been proposed for higher performance, these predictions are supervised by the corresponding L2 loss function directly. H...
Article
1-ms vision systems represent an extreme case of temporal development in video sensing techniques. Moreover, a 1-ms dual-hand tracking system leverages the dexterous functionality of hands and thus serves as a seamless and intuitive interface for Human-Computer Interaction. Deep CNN is promising for high tracking robustness, however, neither GPU-ba...
Article
Full-text available
3D human pose estimation has many important applications in human-computer interaction and human action recognition. Simultaneously achieving real-time speed, varying human number, and high accuracy from a single RGB image is a challenging problem. To this end, this paper proposes a multi-task and multi-level neural network structure with physical...
Article
Full-text available
Compared with the great successes achieved by supervised learning, e.g. convolutional neural network (CNN), unsupervised feature learning is still a highly-challenging task suffering from no training labels. Because of no training labels for reference, blindly reducing the gap between features and image semantics is the most challenging problem. Th...
Article
The spike height of volleyball players is important in volleyball analysis as the quantitative criteria to evaluation players' motions, which not only provides rich information to audiences in live broadcast of sports events but also makes contribution to evaluate and improve the performance of players in strategy analysis and players training. In...
Article
Full-text available
Jump analysis in figure skating is important. Recovering the 3D pose of a figure skater has become increasingly important. However, issues such as restrictions from an athlete’s clothing, self-occlusion, abnormal pose and so on will result in poor results. This paper proposes a multi-technology correction framework to obtain a 3D human pose. The fr...
Article
High frame rate and ultra-low delay matching system plays an increasingly important role in human-machine interactions, because it guarantees high-quality experiences for users. Existing image matching algorithms always generate mismatches which heavily weaken the performance the human-machine-interactive systems. Although many mismatch removal alg...
Article
High frame rate and ultra-low delay are the most essential requirements for building excellent human-machine-interaction systems. As a state-of-the-art local keypoint detection and feature extraction algorithm, A-KAZE shows high accuracy and robustness. Nonlinear scale space is one of the most important modules in A-KAZE, but it not only has at lea...
Article
High frame rate and ultra-low delay matching system plays an important role in various human-machine interactive applications, which demands better performance in matching deformable and out-of-plane rotating objects. Although many algorithms have been proposed for deformation tracking and matching, few of them are suitable for hardware implementat...
Article
Volleyball video analysis plays important roles in providing data for TV contents and developing strategies. Among all the topics of volleyball analysis, qualitative player action recognition is essential because it potentially provides not only the action that being performed but also the quality, which means how well the action is performed. Howe...
Article
Real-time 3D players tracking plays an important role in sports analysis, especially for the live services of sports broadcasting, which have a strict limitation on processing time. For these kinds of applications, 3D trajectories of players contribute to high-level game analysis such as tactic analysis and commercial applications such as TV conten...
Conference Paper
Accurately establishing pixel-level correspondence between images taken from same objects is an essential problem in many computer vision applications, such as 3D reconstruction, simultaneous localization and mapping (SLAM), and augmented reality (AR). Existing local feature descriptor based image matching approaches are unable to avoid mismatches...
Article
Full-text available
Establishing local visual correspondence between video frames is an important and challenging problem in many vision based applications. Local keypoint detection and description based pixel-level matching is a typical way for visual correspondence estimation. Unlike traditional local keypoint descriptor based methods, this paper proposes a comprehe...
Article
In real-time 3D ball tracking of sports analysis in computer vision technology, complex algorithms which assure the accuracy could be time-consuming. Particle filter based algorithm has a large potential to accelerate since the algorithm between particles has the chance to be paralleled in heterogeneous CPU-GPU platform. Still, with the target mult...
Article
Automatic game strategy data acquisition is important for the realization of the professional strategy analysis systems by providing evaluation values such as the team status and the efficacy of plays. The key factor that influences the performance of the strategy data acquisition in volleyball game is the unknown player roles. Player role means th...
Chapter
3D players tracking plays an important role in sports analysis. Tracking of players contributes to high level game analysis such as tactic analysis and commercial applications such as TV contents. Many services like sports live and broadcasting have strict limitation on processing time, thus real-time implementation for 3D players tracking is neces...
Chapter
Volleyball video analysis is important for developing applications such as player evaluation system or tactic analysis system. Among its different topics, player action recognition serves as an elementary building brick for understanding player’s behavior. Most conventional player action recognition methods have limits in real volleyball game due t...
Chapter
Among sports analysis, tracking of athletes’ body parts becomes a popular theme. Marking positions of body parts on the videos which contributes to TV contents and concrete motion capture of athletes which helps promotion of sports technology make sports analysis a commercially-viable research theme. This paper proposes motion state detection based...
Chapter
3D ball tracking is of great significance to sports analysis, which can be utilized to applications such as TV contents and tactic analysis. Some applications require real-time implementation, but a highly accurate tracking algorithm is usually time-consuming. This paper proposes a CPU-GPU platform based particle filter for multi-view ball tracking...
Article
High frame rate and ultra-low delay matching system plays an increasingly important role in human-machine interactive applications which call for higher frame rate and lower delay for a better experience. The large amount of processing data and the complex computation in a local feature based matching system, make it difficult to achieve a high pro...
Article
3D ball tracking is of great significance in ping-pong game analysis, which can be utilized to applications such as TV contents and tactic analysis, with some of them requiring real-time implementation. This paper proposes a CPU-GPU platform based Particle Filter for multi-view ball tracking including 4 proposals. The multi-peak estimation and the...
Article
The ball state tracking and detection technology plays a significant role in volleyball game analysis, whose performance is limited due to the challenges include: 1) the inaccurate ball trajectory; 2) multiple numbers of the ball event category; 3) the large intra-class difference of one event. With the goal of broadcasting supporting for volleybal...
Article
Significant challenges in ball tracking of sports analysis by computer vision technology are: 1) accuracy of estimated 3D ball trajectory under difficult conditions; 2) external forces added by players lead to irregular motions of the ball; 3) unpredictable situations in the real game, i.e. the ball occluded by players and other objects, complex ba...
Conference Paper
High efficiency video coding (HEVC) is a video compression standard that outperforms the predecessor H.264/AVC by doubling the compression efficiency. To enhance the compression accuracy, the partition sizes ranging is from 4x4 to 64x64 in HEVC. However, the manifold partition sizes dramatically increase the encoding complexity. This paper proposes...
Article
Full-text available
High efficiency video coding (HEVC) is a video compression standard that outperforms the predecessor H.264/AVC by doubling the compression efficiency. To enhance the coding accuracy, HEVC adopts sample adaptive offset (SAO), which reduces the distortion of reconstructed pixels using classification based non-linear filtering. In the traditional codi...
Conference Paper
The scalable extension of High Efficiency Video Coding (SHVC) is now being developed by the Joint Collaborative Team on Video (JCT-VC). In SHVC, the enhancement layer (EL) employs the same coding methods as the base layer (BL) for different color components, namely one luminance (luma) and two chrominance (chroma) color components, which causes hea...
Conference Paper
Screen Content Coding (SCC) is the extension of High Efficiency Video Coding (HEVC). Main target of SCC is saving BD-rate for screen videos generated by computers. However encoding time is increased because of new intra modes named Intra Block Copy (IntraBC) and Palette mode to save BD-rate. This paper proposes Sharp Edge Based Classification (SE B...
Conference Paper
Multiple players tracking in volleyball video analysis is very important for developing applications such as tactical analysis system. To obtain a high success rate of tracking, frequent occlusion among players is a problem to be solved. This paper proposes a least square fitting prediction model and a spatial relationship based multi-view eliminat...
Article
Player tracking plays a key role in volleyball tactics analysis. Therefore, many tracking algorithms have been proposed to track and locate the players' positions. However, in a volleyball match, intersection of players wearing the same uniform occurs frequently. Conventional tracking algorithms can hardly handle such complicated situation with hig...
Conference Paper
High efficiency video coding (HEVC) is a video compression standard that outperforms the predecessor H.264/AVC by doubling the compression efficiency. To enhance the coding accuracy, HEVC adopts sample adaptive offset (SAO) which classifies reconstructed pixels into different categories. During the pixel classification, however, SAO cannot use the...
Article
High efficiency video coding (HEVC) is a video compression standard that outperforms the predecessor H.264/AVC by doubling the compression efficiency. To enhance the intra prediction accuracy, 35 intra prediction modes were used in the prediction units (PUs), with partition sizes ranging from 4 x 4 to 64 x 64 in HEVC. However, the manifold predicti...
Conference Paper
Full-text available
High Efficiency Video Coding (HEVC) is the up-to-date video coding standard. Compared to the predecessor H.264/AVC, HEVC can further reduce approximately 50% bit rate on average with the competing perceptual quality. On the other hand, experiment shows that HEVC requires more than 4 times computational complexity during the encoding procedure. In o...
Article
Scalable Video Coding (SVC) is an extension of H.264/AVC, aiming to provide the ability to adapt to heterogeneous networks or requirements. It offers great flexibility for bitstream adaptation in multi-point applications such as videoconferencing. However, transcoding between SVC and AVC is necessary due to the existence of legacy AVC-based systems...
Conference Paper
High Efficiency Video Coding (HEVC), a successor to H.264, is the next generation video compression standard. To enhance the coding efficiency of video frames, 35 intra prediction modes adopted in Prediction Unit (PU) from 4×4 to 64×64 of HEVC. However the improvement is based on the cost of rapid increased complexity. This paper proposes a fast mo...
Article
As an extension of H.264/AVC, Scalable Video Coding (SVC) provides the ability to adapt to heterogeneous networks and user-end requirements, which offers great scalability in multi-point applications such as videoconferencing. However, transcoding between SVC and AVC becomes necessary due to the existence of legacy AVC-based systems. The straightfo...
Conference Paper
Keypoint extraction has lately attracted attention in computer vision. Particularly, Scale-Invariant Feature Transform (SIFT) is one of them and invariant for scale, rotation and illumination change. In addition, the recent advance of machine learning becomes possible to recognize a lot of objects by learning large amount of keypoints. Recently, cl...
Conference Paper
High Efficiency Video Coding (HEVC), a successor to H.264, is the next generation video compression standard. To enhance the coding efficiency of video frames, 35 intra prediction modes adopted in Prediction Unit (PU) from 4×4 to 64×64 of HEVC. However, the improvement is based on the cost of rapid increased complexity performance loss. This paper...
Article
Scalable Video Coding (SVC) is an extension of H.264/AVC, aiming to provide the ability to adapt to heterogeneous networks or requirements. It offers great flexibility for bitstream adaptation in multi-point applications such as videoconferencing. However, transcoding between SVC and AVC is necessary due to the existence of legacy AVC-based systems...
Conference Paper
Full-text available
Intra coding algorithm in High Efficiency Video Coding employs up to 35 directional prediction modes. Upon the end of alleviating the intra encoding complexity, we proposed the candidate mode selection algorithm from analyzing the textures of the source image block. Considering the fine difference between the neighboring prediction directions, we d...
Conference Paper
Scalable Video Coding (SVC) is an extension of H.264/AVC, aiming to provide the ability to adapt to heterogeneous environments. It offers great flexibility for bitstream adaptation in multi-point applications such as videoconferencing. However, transcoding between SVC and AVC is necessary due to the existence of legacy AVC-based systems. This paper...
Conference Paper
As an extension of H.264/AVC, Scalable Video Coding (SVC) provides the ability to adapt to heterogeneous requirements. However, transcoding between SVC and AVC becomes necessary due to the existence of legacy AVC-based systems. The straightforward full re-encoding method requires great computational cost, and fast SVC-to-AVC spatial transcoding tec...
Conference Paper
HMD (head-mounted display) as a promising device is becoming more and more important in daily life. Many companies has been working on it for the next generation human-interface system. This paper presents a real-time hand gesture interface based on TSL (Hue, Saturation, Luminance) adaptive area detection and distance signature with single camera....
Article
Scalable Video Coding (SVC) was standardized as an extension of H.264/AVC with the intention to provide flexible adaptation to heterogeneous networks and different end-user requirements, which provides great scalability in multi-point applications such as video conferencing. However, due to the existence of H.264/AVC-based systems, transcoding betw...
Article
The traditional Lagrange RDO algorithm assumes the transformed residues as memory less random variables, and then doesn't perform well when the prediction residues posses strong temporal correlations. We extend the RDO by modeling the residues as the first order Markov source and calibrating the distortion model with the piecewise approximation fun...
Conference Paper
Rate distortion optimization (RDO) algorithm plays the vital role in the up to date hybrid video codec H.264/AVC. The RDO algorithm of H.264/AVC reference software is built up by assuming that the transformed residues are memoryless variables. However, our experiments reveal that, for some sequences, the strong temporal correlations exist in the pr...
Conference Paper
Hand gesture interfaces are more intuitive and convenient than traditional interfaces. They are the most important parts in the relationship between users and devices. Hand tracking for hand gesture interfaces is an active area of research in image processing. However, previous works have limits such as requiring the use of multiple camera or senso...
Conference Paper
As an extension of AVC, SVC provides the ability to adapt to heterogeneous environments. However, transcoding between SVC and AVC becomes necessary due to the existence of legacy AVC-based systems. This paper proposes a low-complexity SVC-to-AVC CGS transcoder in the pixel domain, which achieves approximately the same coding efficiency as the full...
Conference Paper
Object tracking is a key process for various image recognition applications, and many algorithms have been proposed in this field. Especially, particle filter has possibility for tracking objects steadily thanks to prediction using many particles. However, other objects that are a similar color or shape with a tracking object hijack a tracking regi...
Conference Paper
Scale-Invariant Feature Transform (SIFT) has lately attracted attention in computer vision as a robust keypoint detection algorithm which is invariant for scale, rotation and illumination change. However, its computational complexity is too high to apply practical real-time applications. This paper proposes a low complexity keypoint extraction algo...
Article
In the HEVC standard, UIP (unified intra prediction) is included as one of the new coding tools in the latest HM software, which supports 33 different directions in addition to the DC prediction mode. It represents directional structures more accurately, and performs remarkable bit rate saving. However, UIP also significantly increases the burdens...
Article
With the increasing demand of high video quality and large image size, adaptive interpolation filter (AIF) addresses these issues and conquers the time varying effects resulting in increased coding efficiency, comparing with recent H.264 standard. However, currently most AIF algorithms are based on either frame level or macroblock (MB) level, which...
Article
Different encoding modes for variable block size are available in the H.264/AVC standard in order to offer better coding quality. However, this also introduces huge computation time due to the exhaustive check for all modes. In this paper, a fast spatial DIRECT mode decision method for profiles supporting B frame encoding (main profile, high profil...
Conference Paper
In this paper, a fast spatial DIRECT mode decision method for B frame in H.264/AVC is proposed. It is based on a statistical analysis on multiple video sequences, and the strong relationship of mode selection and rate-distortion (RD) cost between the current DIRECT macroblock (MB) and the co-located MBs is observed. With the check of mode condition...
Conference Paper
With the increasing demand of high video quality and large image size, adaptive interpolation filter (AIF) addresses these issues and conquers the time varying effects resulting in increased coding efficiency, comparing with recent H.264 standard. However, currently most AIF algorithms are based on either frame level or macroblock (MB) level, which...
Article
Large coding unit which is also known as super macroblock, has already been adopted in the test model of next generation coding standard called high efficiency video coding. The coding unit which is larger than 16x16 and less than or equal to 64x64 provides great bit rate saving while the coding complexity increases dramatically. In this paper, we...
Article
Previous research illustrates that LRU replacement policy is not efficient when applications exhibit a distant re-reference interval. Recently RRIP policy is proposed to improve the performance for such kind of workloads. However, the lack of access recency information in RRIP confuses the replacement policy to make the accurate prediction. To enha...