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1.
Virus Genes ; 53(1): 21-34, 2017 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-27613417

RESUMO

The complete genomes of a skunkpox, volepox, and raccoonpox virus were sequenced and annotated. Phylogenetic analysis of these genomes indicates that although these viruses are all orthopoxviruses, they form a distinct clade to the other known species. This supports the ancient divergence of the North American orthopoxviruses from other members of the orthopoxviruses. Only two open reading frames appear to be unique to this group of viruses, but a relatively small number of insertions/deletions contribute to the varied gene content of this clade. The availability of these genomes will help determine whether skunkpox and volepox viruses share the characteristics that make raccoonpox a useful vaccine vector.


Assuntos
Genoma Viral , Orthopoxvirus/classificação , Orthopoxvirus/genética , Infecções por Poxviridae/epidemiologia , Infecções por Poxviridae/virologia , Animais , Biologia Computacional/métodos , Regulação Viral da Expressão Gênica , Humanos , Anotação de Sequência Molecular , Mutação , América do Norte/epidemiologia , Fases de Leitura Aberta , Filogenia , Análise de Sequência de DNA
2.
IEEE Trans Vis Comput Graph ; 22(5): 1517-1526, 2016 05.
Artigo em Inglês | MEDLINE | ID: mdl-28113142

RESUMO

We introduce a technique of calibrating camera motions in basketball videos. Our method particularly transforms player positions to standard basketball court coordinates and enables applications such as tactical analysis and semantic basketball video retrieval. To achieve a robust calibration, we reconstruct the panoramic basketball court from a video, followed by warping the panoramic court to a standard one. As opposed to previous approaches, which individually detect the court lines and corners of each video frame, our technique considers all video frames simultaneously to achieve calibration; hence, it is robust to illumination changes and player occlusions. To demonstrate the feasibility of our technique, we present a stroke-based system that allows users to retrieve basketball videos. Our system tracks player trajectories from broadcast basketball videos. It then rectifies the trajectories to a standard basketball court by using our camera calibration method. Consequently, users can apply stroke queries to indicate how the players move in gameplay during retrieval. The main advantage of this interface is an explicit query of basketball videos so that unwanted outcomes can be prevented. We show the results in Figs. 1, 7, 9, 10 and our accompanying video to exhibit the feasibility of our technique.


Assuntos
Gráficos por Computador , Movimento (Física) , Basquetebol , Humanos
3.
IEEE Trans Image Process ; 24(1): 80-93, 2015 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-25330489

RESUMO

We present a novel two-pass framework for counting the number of people in an environment, where multiple cameras provide different views of the subjects. By exploiting the complementary information captured by the cameras, we can transfer knowledge between the cameras to address the difficulties of people counting and improve the performance. The contribution of this paper is threefold. First, normalizing the perspective of visual features and estimating the size of a crowd are highly correlated tasks. Hence, we treat them as a joint learning problem. The derived counting model is scalable and it provides more accurate results than existing approaches. Second, we introduce an algorithm that matches groups of pedestrians in images captured by different cameras. The results provide a common domain for knowledge transfer, so we can work with multiple cameras without worrying about their differences. Third, the proposed counting system is comprised of a pair of collaborative regressors. The first one determines the people count based on features extracted from intracamera visual information, whereas the second calculates the residual by considering the conflicts between intercamera predictions. The two regressors are elegantly coupled and provide an accurate people counting system. The results of experiments in various settings show that, overall, our approach outperforms comparable baseline methods. The significant performance improvement demonstrates the effectiveness of our two-pass regression framework.


Assuntos
Biometria/métodos , Processamento de Imagem Assistida por Computador/métodos , Humanos , Movimento , Gravação em Vídeo
4.
IEEE Trans Image Process ; 24(2): 709-23, 2015 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-25546860

RESUMO

The recent advances in imaging devices have opened the opportunity of better solving the tasks of video content analysis and understanding. Next-generation cameras, such as the depth or binocular cameras, capture diverse information, and complement the conventional 2D RGB cameras. Thus, investigating the yielded multimodal videos generally facilitates the accomplishment of related applications. However, the limitations of the emerging cameras, such as short effective distances, expensive costs, or long response time, degrade their applicability, and currently make these devices not online accessible in practical use. In this paper, we provide an alternative scenario to address this problem, and illustrate it with the task of recognizing human actions. In particular, we aim at improving the accuracy of action recognition in RGB videos with the aid of one additional RGB-D camera. Since RGB-D cameras, such as Kinect, are typically not applicable in a surveillance system due to its short effective distance, we instead offline collect a database, in which not only the RGB videos but also the depth maps and the skeleton data of actions are available jointly. The proposed approach can adapt the interdatabase variations, and activate the borrowing of visual knowledge across different video modalities. Each action to be recognized in RGB representation is then augmented with the borrowed depth and skeleton features. Our approach is comprehensively evaluated on five benchmark data sets of action recognition. The promising results manifest that the borrowed information leads to remarkable boost in recognition accuracy.

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