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.
Current experiments with HCIs have shown a high demand for more natural interaction paradigms. Gestures are thereby considered the most important cue besides speech. In order to recognize gestures it is necessary to extract meaningful motion features from the body. Up to now mostly marker based tracking systems are used in virtual reality environments, since these were traditionally more reliable...
Generating statistically significant datasets for face matching system evaluation is a laborious and expensive process. Capturing variables such as atmospheric turbulence and other weather conditions especially with respect to face recognition at a distance exacerbate the problem further. It is even more difficult to work on system issues for long-range systems that impact the collection phase such...
In this paper we study some problems important for large-scale human age estimation. First, we study age estimation performance under variations across race and gender. Through a large number of age estimation experiments, significant differences are observed for age estimation between “no crossing” and “crossing.” Our study discovers that crossing race and gender can result in significant error increases...
We present a novel viewpoint which approaches the structural correspondence across an image stack in the 3D space as solving a contour grouping problem. Finding 3D cellular tubes becomes finding closed contours. We derive grouping cues between cells in adjacent slices based on their ability to relate in the 3D space. Those that form a long 3D tube in the space become the most salient contour, while...
Note-taking is a fundamental learning activity that should be practiced by every serious secondary or post-secondary student. Research has shown that the mental processing that occurs during note-taking helps students consolidate and retain classroom instruction, even if they never study their notes afterward. However, students who are legally blind can have difficulty taking notes in the classroom...
We present a new method for content-aware image resizing based on a framework of global optimization. We show that the basic resizing problem can be formulated as a convex quadratic program. Furthermore, we demonstrate how the basic framework may be extended to prevent foldovers of the underlying mesh; encourage the magnification of salient regions; and preserve straight line structures. We show results...
Two dimensional shape models have been successfully applied to solve many problems in computer vision such as object tracking, recognition and segmentation. Typically, 2D shape models (e.g. Point Distribution Models, Active Shape Models) are learned from a discrete set of image landmarks once the rigid transformations are removed applying Procrustes Analysis (PA). However, the standard PA process...
In human facial behavioral analysis, Action Unit (AU) coding is a powerful instrument to cope with the diversity of facial expressions. Almost all of the work in the literature for facial action recognition is based on 2D camera images. Given the performance limitations in AU detection with 2D data, 3D facial surface information appears as a viable alternative. 3D systems capture true facial surface...
Facial expressions are one important nonverbal communication cue, as they can provide feedback in conversations between people and also in human-robot interaction. This paper presents an evaluation of three standard pattern recognition techniques (active appearance models, gabor energy filters, and raw images) for facial feedback interpretation in terms of valence (success and failure) and compares...
Facial expression analysis is essential for human-computer interface (HCI). For different expressions, different parts of the face play different roles with the distinct movement of facial muscles. In this work, we propose to learn the weight associated with different facial regions for different expressions. The facial feature points are first located accurately based on a graphical model. Based...
This paper presents a method to assist in the tedious procedure of reconstructing ceramic vessels from unearthed archaeological shards or fragments using 3D computer vision-enabling technologies. The method uses vessels surface markings combined with a generic model to produce a representation of what the original vessel may have looked like. Generic vessel models used are based on a host of factors...
Contextual information can be used both to reduce computations and to increase accuracy and this paper presents how it can be exploited for people surveillance in terms of perspective (i.e. weak scene calibration) and appearance of the objects of interest (i.e. relevance feedback on the training of a classifier). These techniques are applied to a pedestrian detector that exploits covariance descriptors...
Multiple camera views of a scene are utilized to detect and reconstruct object surfaces in three dimensions. Special attention is paid to the reconstruction of occluded objects which are only partially visible. Input images can be obtained from either an array of cameras or a single moving camera. The formulation is based on a capture and display technique developed in the optics community. Various...
This paper presents a new method for improving region segmentation in sequences of images when temporal and spatial prior context is available. The proposed technique uses elementary classifiers on infra-red, polarimetic and video data to obtain a coarse segmentation per-pixel. Contextual information is exploited in a Bayesian formulation to smooth the segmentation between frames. This is a general...
Varying illumination is a challenging issue in many computer vision problems (e.g., tagging, matching, and tracking), while in inverse rendering, people are interested in estimating illumination from rendered images or videos. Can these two techniques be combined together to form a unified framework for vehicle tracking and lighting learning? This paper gives probably the first thought in this joint...
This paper presents a new online multi-classifier boosting algorithm for learning object appearance models. In many cases the appearance model is multi-modal, which we capture by training and updating multiple strong classifiers. The proposed algorithm jointly learns the classifiers and a soft partitioning of the input space, defining an area of expertise for each classifier. We show how this formulation...
Tracking and detection of objects often require to apply complex models to cope with the large intra-class variability of the foreground as well as the background class. In this work, we reduce the complexity of a binary classification problem by a context-driven approach. The main idea is to use a hidden multi-class representation to capture multi-modalities in the data finally providing a binary...
The assembly of fragments into vessels is a significant task in the analysis of archaeological finds. The current method of reconstruction which relies on experts is time-consuming and laborious, and leads only to a fraction of reconstructions possible. Automated tools have been able to assemble at most two or three dozen fragments, while in practice, archaeologists deal with hundreds and thousands...
Blind people face a number of challenges when interacting with their environments because so much information is encoded visually. Text is pervasively used to label objects, colors carry special significance, and items can easily become lost in surroundings that cannot be quickly scanned. Many tools seek to help blind people solve these problems by enabling them to query for additional information,...
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.