A multi-modal person perception framework for socially interactive mobile service robots

In order to meet the increasing demands of mobile service robot applications, a dedicated perception module is an essential requirement for the interaction with users in real-world scenarios. In particular, multi sensor fusion and human re-identification are recognized as active research fronts. Through this paper we contribute to the topic and present a modular detection and tracking system that models position and additional properties of persons in the surroundings of a mobile robot. The proposed system introduces a probability-based data association method that besides the position can incorporate face and color-based appearance features in order to realize a re-identification of persons when tracking gets interrupted. The system combines the results of various state-of-the-art image-based detection systems for person recognition, person identification and attribute estimation. This allows a stable estimate of a mobile robot’s user, even in complex, cluttered environments with long-lasting occlusions. In our benchmark, we introduce a new measure for tracking consistency and show the improvements when face and appearance-based re-identification are combined. The tracking system was applied in a real world application with a mobile rehabilitation assistant robot in a public hospital. The estimated states of persons are used for the user-centered navigation behaviors, e.g., guiding or approaching a person, but also for realizing a socially acceptable navigation in public environments

HUMAN GENDER CLASSIFICATION USING KINECT SENSOR: A REVIEW

Human Gender Classification using Kinect sensor aims to classifying people’s gender based on their outward appearance. Application areas of Kinect sensor technology includes security, marketing, healthcare, and gaming. However, because of the changes in pose, attire, and illumination, gender determination with the Kinect sensor is not a trivial task. It is based on a variety of characteristics, including biological, social network, face, and body aspects. In recent years, gender classification that utilizes the Kinect sensor became a popular and essential way for accurate gender classification. A variety of methods and approaches, like machine learning, convolutional neural networks, sport vector machine (SVM), etc., have been used for gender classification using a Kinect sensor. This paper presents the state of the art for gender classification, with a focus on the features, databases, procedures, and algorithms used in it. A review of recent studies on this subject using the Kinect sensor and other technologies is provided, together with information on the variables that affect the classification\u27s accuracy. In addition, several publicly accessible databases or datasets are used by researchers to classify people by gender are covered. Finlay, this overview offers insightful information about the potential future avenues for research on Kinect-based human gender classification

Human Action Recognition with RGB-D Sensors

Human action recognition, also known as HAR, is at the foundation of many different applications related to behavioral analysis, surveillance, and safety, thus it has been a very active research area in the last years. The release of inexpensive RGB-D sensors fostered researchers working in this field because depth data simplify the processing of visual data that could be otherwise difficult using classic RGB devices. Furthermore, the availability of depth data allows to implement solutions that are unobtrusive and privacy preserving with respect to classic video-based analysis. In this scenario, the aim of this chapter is to review the most salient techniques for HAR based on depth signal processing, providing some details on a specific method based on temporal pyramid of key poses, evaluated on the well-known MSR Action3D dataset

Multi-Modality Human Action Recognition

Human action recognition is very useful in many applications in various areas, e.g. video surveillance, HCI (Human computer interaction), video retrieval, gaming and security. Recently, human action recognition becomes an active research topic in computer vision and pattern recognition. A number of action recognition approaches have been proposed. However, most of the approaches are designed on the RGB images sequences, where the action data was collected by RGB/intensity camera. Thus the recognition performance is usually related to various occlusion, background, and lighting conditions of the image sequences. If more information can be provided along with the image sequences, more data sources other than the RGB video can be utilized, human actions could be better represented and recognized by the designed computer vision system.;In this dissertation, the multi-modality human action recognition is studied. On one hand, we introduce the study of multi-spectral action recognition, which involves the information from different spectrum beyond visible, e.g. infrared and near infrared. Action recognition in individual spectra is explored and new methods are proposed. Then the cross-spectral action recognition is also investigated and novel approaches are proposed in our work. On the other hand, since the depth imaging technology has made a significant progress recently, where depth information can be captured simultaneously with the RGB videos. The depth-based human action recognition is also investigated. I first propose a method combining different type of depth data to recognize human actions. Then a thorough evaluation is conducted on spatiotemporal interest point (STIP) based features for depth-based action recognition. Finally, I advocate the study of fusing different features for depth-based action analysis. Moreover, human depression recognition is studied by combining facial appearance model as well as facial dynamic model

Learning from human-robot interaction

En los últimos años cada vez es más frecuente ver robots en los hogares. La robótica está cada vez más presente en muchos aspectos de nuestras vidas diarias, en aparatos de asistencia doméstica, coches autónomos o asistentes personales. La interacción entre estos robots asistentes y los usuarios es uno de los aspectos clave en la robótica de servicio. Esta interacción necesita ser cómoda e intuitiva para que sea efectiva su utilización. Estas interacciones con los usuarios son necesarias para que el robot aprenda y actualice de manera natural tanto su modelo del mundo como sus capacidades. Dentro de los sistemas roboticos de servicio, hay muchos componentes que son necesarios para su buen funcionamiento. Esta tesis esta centrada en el sistema de percepción visual de dichos sistemas.Para los humanos la percepción visual es uno de los componentes más esenciales, permitiendo tareas como reconocimiento de objetos u otras personas, o estimación de información 3D. Los grandes logros obtenidos en los últimos años en tareas de reconocimiento automático utilizan los enfoques basados en aprendizaje automático, en particular técnicas de deep learning. La mayoría de estos trabajos actuales se centran en modelos entrenados 'a priori' en un conjunto de datos muy grandes. Sin embargo, estos modelos, aunque entrenados en una gran cantidad de datos, no pueden, en general, hacer frente a los retos que aparecen al tratar con datos reales en entornos domésticos. Por ejemplo, es frecuente que se de el caso de tener nuevos objetos que no existían durante el entrenamiento de los modelos. Otro reto viene de la dispersión de los objetos, teniendo objetos que aparecen muy raramente y por lo tanto habia muy pocos, o ningún, ejemplos en los datos de entenamiento disponibles al crear el modelo.Esta tesis se ha desarrollado dentro del contexto del proyecto IGLU (Interactive Grounded Language Understanding). Dentro del proyecto y sus objetivos, el objetivo principal de esta Tesis doctoral es investigar métodos novedosos para que un robot aprenda de manera incremental mediante la interacción multimodal con el usuario.Desarrollando dicho objetivo principal, los principales trabajos desarrollados durante esta tesis han sido:-Crear un benchmark más adecuado para las tareas de aprendizaje mediante la interacción natural de usuario y robot. Por ejemplo, la mayoría de los datasets para la tarea de reconocimiento de objetos se centra en fotos de diferentes escenarios con múltiples clases por foto. Es necesario un dataset que combine interacción usuario robot con aprendizaje de objetos.-Mejorar sistemas existentes de aprendizaje de objetos y adecuarlos para aprendizaje desde la interacción multimodal humana. Los trabajos de detección de objetos se focalizan en detectar todos los objetos aprendidos en una imagen. Nuestro objetivo es usar la interacción para encontrar el objeto de referencia y aprenderlo incrementalmente.-Desarrollar métodos de aprendizaje incremental que se puedan utilizar en escenarios incrementales, p.e., la aparición de una nueva clase de objeto o cambios a lo largo del tiempo dentro de una clase objetos. Nuestro objetivo es diseñar un sistema que pueda aprender clases desde cero y que pueda actualizar los datos cuando estos aparecen.-Crear un completo prototipo para el aprendizaje incremental y multimodal usando la interacción humana-robot. Se necesita realizar la integración de los distintos métodos desarrollados como parte de los otros objetivos y evaluarlo.<br /

Articulated motion and deformable objects

This guest editorial introduces the twenty two papers accepted for this Special Issue on Articulated Motion and Deformable Objects (AMDO). They are grouped into four main categories within the field of AMDO: human motion analysis (action/gesture), human pose estimation, deformable shape segmentation, and face analysis. For each of the four topics, a survey of the recent developments in the field is presented. The accepted papers are briefly introduced in the context of this survey. They contribute novel methods, algorithms with improved performance as measured on benchmarking datasets, as well as two new datasets for hand action detection and human posture analysis. The special issue should be of high relevance to the reader interested in AMDO recognition and promote future research directions in the field

Robust perception of humans for mobile robots RGB-depth algorithms for people tracking, re-identification and action recognition

Human perception is one of the most important skills for a mobile robot sharing its workspace with humans. This is not only true for navigation, because people have to be avoided differently than other obstacles, but also because mobile robots must be able to truly interact with humans. In a near future, we can imagine that robots will be more and more present in every house and will perform services useful to the well-being of humans. For this purpose, robust people tracking algorithms must be exploited and person re-identification techniques play an important role for allowing robots to recognize a person after a full occlusion or after long periods of time. Moreover, they must be able to recognize what humans are doing, in order to react accordingly, helping them if needed or also learning from them. This thesis tackles these problems by proposing approaches which combine algorithms based on both RGB and depth information which can be obtained with recently introduced consumer RGB-D sensors. Our key contribution to people detection and tracking research is a depth-clustering method which allows to apply a robust image-based people detector only to a small subset of possible detection windows, thus decreasing the number of false detections while reaching high computational efficiency. We also advance person re-identification research by proposing two techniques exploiting depth-based skeletal tracking algorithms: one is targeted to short-term re-identification and creates a compact, yet discrimative signature of people based on computing features at skeleton keypoints, which are highly repeatable and semantically meaningful; the other extract long-term features, such as 3D shape, to compare people by matching the corresponding 3D point cloud acquired with a RGB-D sensor. In order to account for the fact that people are articulated and not rigid objects, it exploits 3D skeleton information for warping people point clouds to a standard pose, thus making them directly comparable by means of least square fitting. Finally, we describe an extension of flow-based action recognition methods to the RGB-D domain which computes motion over time of persons' 3D points by exploiting joint color and depth information and recognizes human actions by classifying gridded descriptors of 3D flow. A further contribution of this thesis is the creation of a number of new RGB-D datasets which allow to compare different algorithms on data acquired by consumer RGB-D sensors. All these datasets have been publically released in order to foster research in these fields