Motion-Based Sign Language Video Summarization using Curvature and Torsion

An interesting problem in many video-based applications is the generation of short synopses by selecting the most informative frames, a procedure which is known as video summarization. For sign language videos the benefits of using the $t$-parameterized counterpart of the curvature of the 2-D signer's wrist trajectory to identify keyframes, have been recently reported in the literature. In this paper we extend these ideas by modeling the 3-D hand motion that is extracted from each frame of the video. To this end we propose a new informative function based on the $t$-parameterized curvature and torsion of the 3-D trajectory. The method to characterize video frames as keyframes depends on whether the motion occurs in 2-D or 3-D space. Specifically, in the case of 3-D motion we look for the maxima of the harmonic mean of the curvature and torsion of the target's trajectory; in the planar motion case we seek for the maxima of the trajectory's curvature. The proposed 3-D feature is experimentally evaluated in applications of sign language videos on (1) objective measures using ground-truth keyframe annotations, (2) human-based evaluation of understanding, and (3) gloss classification and the results obtained are promising.Comment: This work has been submitted to the IEEE for possible publication. Copyright may be transferred without notice, after which this version may no longer be accessibl

Detección de situaciones de violencia física interpersonal en videos usando técnicas de aprendizaje profundo

Diseña una arquitectura con el modelo de red neuronal convolucional Xception y LSTM para la detección de violencia física interpersonal en los videos de sistemas de vigilancia. Debido al aumento de inseguridad en el país y como medida preventiva, se buscó reforzar el sistema de videovigilancia, donde se enfocó en la necesidad de integrar nuevas tecnologías para supervisar la seguridad ciudadana como es el caso del uso de la visión artificial. Para el entrenamiento, validación y prueba de la arquitectura del modelo propuesto, se utilizó los conjuntos de datos Hockey Fight Dataset y Real Life Violence Situations Dataset. Los resultados obtenidos en la exactitud de nuestra propuesta en el conjunto de datos Hockey Fight Dataset supero a todos los demás métodos. En el caso del conjunto de datos Real Life Violence Situations Dataset que cuenta 2000 videos en contraste de otros conjuntos de datos utilizados para la detección de violencia, se obtuvieron buenos resultados en la exactitud mayores al 90%.Perú. Universidad Nacional Mayor de San Marcos. Vicerrectorado de Investigación y Posgrado. Proyectos de Investigación con Financiamiento para Grupos de Investigación. PCONFIGI. Código: C21201361. Resolución: 005753-2021-R/UNMS

Surveillance video summarization based on trajectory rarity measure

The dynamic video summarization of surveillance videos has several critical applications, mainly due to the wide availability of digital cameras in environments such as airports, train and bus stations, shopping centers, stadiums, buildings, schools, hospitals, roads, among others. This study presents an approach for the generation of dynamic summary on surveillance video domain based on human trajectories. It has an emphasis on trajectory descriptors in conjunction with the unsupervised clustering method. Our approach contribute to existing literature concerning the combination of methods and objectives. We hypothesize that the clustering of trajectories permits to identify rare trajectories base on their morphology. The clustering as an output provides numerous subsets of trajectories or clusters and the number of elements of a specific cluster is used to determine their rarity. Those subsets with few components are rare while the others that have a high number of elements are considered ordinary; therefore, the implications of our study show that is possible to use unsupervised clustering for automatic detection of rare trajectories based on their morphology and with this information segment videos. We experimented with different sets of trajectories segmenting the rare videos from our ground truth.Trabajo de investigació