The Infona portal uses cookies, i.e. strings of text saved by a browser on the user's device. The portal can access those files and use them to remember the user's data, such as their chosen settings (screen view, interface language, etc.), or their login data. By using the Infona portal the user accepts automatic saving and using this information for portal operation purposes. More information on the subject can be found in the Privacy Policy and Terms of Service. By closing this window the user confirms that they have read the information on cookie usage, and they accept the privacy policy and the way cookies are used by the portal. You can change the cookie settings in your browser.
Person re-identification is best known as the problem of associating a single person that is observed from one or more disjoint cameras. The existing literature has mainly addressed such an issue, neglecting the fact that people usually move in groups, like in crowded scenarios. We believe that the additional information carried by neighboring individuals provides a relevant visual context that can...
Deep learning based approaches proved to be dramatically effective to address many computer vision applications, including "face recognition in the wild". It has been extensively demonstrated that methods exploiting Deep Convolutional Neural Networks (DCNN) are powerful enough to overcome to a great extent many problems that negatively affected computer vision algorithms based on hand-crafted...
Understanding where people attention focuses is a challenging and extremely valuable task that can be solved using computer vision technologies. In this paper we address this problem on surveillance-like scenarios, where head and body imagery are usually low resolution. We propose a method to profile the attention of people moving in a known space. We exploit coarse gaze estimation and a novel model...
Human activity recognition is a fundamental problem in computer vision with many applications such as video retrieval, automatic visual surveillance and human computer interaction. Sports represent one of the most viewed content on digital tv and the web. Automatically collected statistics of team sports game play represent actionable information for many end users such as coaches and broadcast speakers...
In this paper we present an efficient and accurate method to aggregate a set of Deep Convolutional Neural Network (CNN) responses, extracted from a set of image windows. CNN features are usually computed on the whole frame or with a dense multi scale approach. There is evidence that using multiple windows yields a better image representation nonetheless it is still not clear how windows should be...
In this paper we describe a new dataset, under construction, acquired inside the National Museum of Bargello in Florence. It was recorded with three IP cameras at a resolution of 1280 × 800 pixels and an average framerate of five frames per second. Sequences were recorded following two scenarios. The first scenario consists of visitors watching different artworks (individuals), while the second one...
An important task in computer vision is object localization and recognition within images and video. Achieving real-time object localization and recognition on low-power devices is especially relevant in the context of wearable technologies. Indeed, wearable devices have a reduced size and cost and limited computational power leading to a challenging scenario for classical computer vision algorithms...
In this paper we describe an approach to automatically improving the efficiency of soft cascade-based person detectors. Our technique addresses the two fundamental bottlenecks in cascade detectors: the number of weak classifiers that need to be evaluated in each cascade, and the total number of detection windows to be evaluated. By simply observing a soft cascade operating on a scene, we learn scale...
In this paper we propose a local space-time descriptor to be employed for behaviour analysis in video-surveillance applications. We show how this local video representation is able to extract scene semantics in both a supervised (behaviour recognition) and semi-supervised (anomaly detection) setup. Our approach yields state-of-the art performance on two publicly available datasets and is not computationally...
This article describes an approach to adaptive video coding for video surveillance applications. Using a combination of low-level features with low computational cost, we show how it is possible to control the quality of video compression so that semantically meaningful elements of the scene are encoded with higher fidelity, while background elements are allocated fewer bits in the transmitted representation...
In modern video surveillance systems, pan-tilt-zoom (PTZ) cameras certainly have the potential to allow the coverage of wide areas with a much smaller number of sensors, compared to the common approach of fixed camera networks. This paper describes a general framework that aims at exploiting the capabilities of modern PTZ cameras in order to acquire high resolution images of body parts, such as the...
In many application scenarios digital images play a basic role and often it is important to assess if their content is realistic or has been manipulated to mislead watcher's opinion. Image forensics tools provide answers to similar questions. This paper, in particular, focuses on the problem of detecting if a feigned image has been created by cloning an area of the image onto another zone to make...
In this paper we propose a new method for human action categorization by using an effective combination of novel gradient and optic flow descriptors, and creating a more effective codebook modeling the ambiguity of feature assignment in the traditional bag-of-words model. Recent approaches have represented video sequences using a bag of spatio-temporal visual words, following the successful results...
Set the date range to filter the displayed results. You can set a starting date, ending date or both. You can enter the dates manually or choose them from the calendar.