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.
Barnacles are one of the major fouling organisms at electric power plants. They cling to the inside of pipes and the surface of steam condensers of the power plants, thus reducing the stream of seawater into the power plants. Furthermore, they erode the pipes and the steam condensers. A continuous auto-detection system of barnacle larvae is necessary to decide the best time for using antifouling techniques...
This paper describes our algorithms for players tracking and ball detection for an automatic broadcast tennis video annotation. The system detects and tracks the players using a robust non-parametric procedure for estimating density gradients called the mean shift algorithm. The basic mean shift tracking algorithm assumes that the target object has to separate sufficiently from background, but this...
This paper presents a novel method for detecting motion regions in image sequences obtained by rapidly moving cameras in fully 3-D scenes. The proposed method mainly focuses on the situations that the backgrounds of the image sequences change rapidly. It has three innovations over existing methods: First, it presents a new initialization method to fast and sparsely gather information of the background...
Video surveillance systems are commonly used by security personnel to monitor and record activity in buildings, public gatherings, busy roads, and parking lots. These systems allow many cameras to be observed by a small number of trained human operators but suffer from potential operator fatigue and lack of attention due to the large amount of information provided by cameras which can distract the...
Visual servoing has been based on geometric features for a long time. Recent works have highlighted the interest of taking into account the photometric information of the entire image. This approach was tackled with images of perspective cameras. We propose, in this paper, to adapt this technique to central cameras. This generalization allows to apply this kind of method to wide field of view cameras...
This paper describes a generic method for vision-based navigation in real urban environments. The proposed approach relies on a representation of the scene based on spherical images augmented with depth information and a spherical saliency map, both constructed in a learning phase. Saliency maps are built by analyzing useful information of points which best condition spherical projections constraints...
People consistent labeling across multiple cameras in the scene with multiple planes ground is a challenging task. We propose a simple but effective method to cope with it. In our method, camera calibration is not needed, the scene is not constrained to a planar ground and the cameras can be set at any oblique angles. The homography induced by the plane at a certain height parallel to the lowest groune...
Vision-based animal behavior analysis is a critical and interesting problem for both biologists and computer vision scientists. In this paper, an automatic system for detecting behaviors of fruit flies is presented. Firstly, we propose an ellipse model to fit the contours of fruit flies, which efficiently detects fruit flies in a single frame. Then we associate the detection results together to form...
There is a new measurement method of computerized temporomandibular joint axiography presented in the paper. In the article there is presented the results of the movement analysis of the optoelectronic markers coupled with mandible and the transformation method of camera views into the trajectory of invisible temporomandibular joint parts, especially in localization of invisible rotation axis. The...
In facility management, analysis of customer trajectories in office complexes is considered critical. In this paper, we propose a novel approach for the visualization of customer flow in an office complex over a long period of time. We expressed the variation in the trajectories with respect to time by using a mixture model; this was used for the visualization of the trajectory flows. The effectiveness...
We describe a method for generating an informative wide-view image using images captured by a moving camera. The generated image allows for events in the scene observed by the camera to be understood easily. Our method does not use 3D shape information explicitly. Instead, it employs the trajectory of feature points across multiple images and generates a composite image by taking into account the...
The automatic detection of meaningful phases in a soccer game depends on the accurate localization of players and the ball at each moment. However, the automatic analysis of soccer sequences is a challenging task due to the presence of fast moving multiple objects. For this purpose, we present a multi-camera analysis system that yields the position of the ball and players on a common ground plane...
Person localization is fundamental in human centered computing, since person should be localized before being actively serviced. This paper proposed a robust approach to localize person based on the geometric constraints in multi-camera environment. The proposed algorithm has several advantages: 1) no assumption on the positions and orientations of cameras except the cameras should have certain common...
We present a procedure for egomotion estimation from visual input of a stereo pair of video cameras. The 3D egomotion problem, which has six degrees of freedom in general, is simplified to four dimensions and further decomposed to two two-dimensional subproblems. The decomposition allows us to use a voting strategy to identify the most probable solution, avoiding the random sampling (RANSAC) or other...
In this work, we propose a feedback scheme for simultaneous thermal-visible video registration, sensor fusion, and tracking for online video surveillance applications. The video registration is based on a RANSAC trajectory-to-trajectory matching that estimates an affine transformation matrix that maximizes the corresponding trajectory points and overlapping of foreground thermal and visible pixels...
This paper proposes a real-time probabilistic solution to the problem of camera motion estimation in a video sequence. Instead of using explicit tracking of features, it only uses instantaneous image intensity variations without prior estimation of optical flow. We represent the camera motion as a probability density which is constructed from the individual motion densities, estimated from spatio-temporal...
The position of a world point's solar shadow depends on its geographical location, the geometrical relationship between the orientation of the sunshine and the ground plane where the shadow casts. This paper investigates the property of solar shadow trajectories on a planar surface and shows that camera parameters, latitude, longitude can be estimated from two observed shadow trajectories. Our contribution...
This paper offers a real-time approach for simultaneously determining spacecraft motion and multiple 3D planar surfaces for spacecraft safe landing. The approach contains three algorithms: a multiple homography alignment algorithm, which constructs homographies under unified epipolar geometry; a closed-form motion estimation algorithm; and a simple routine for surface slope estimation. This approach...
This paper is about the automated discovery and mapping of surfaces using a stereo pair. We begin with the observation that for any workspace which is topologically connected (i.e. does not contain free flying islands) there exists a single surface that covers the entirety of the workspace. We call this surface the covering surface. We assume that while this surface is complex and self intersecting...
In this paper, a method to control the movement of a mouse pointer using simple hand gestures and a webcam is proposed. A real-time tracking algorithm is implemented based on adaptive skin detection and motion analysis. Using the history of motion, the trajectory of the movement of the hand is drawn and then used to identify a gesture. A region of interest algorithm is proposed, in order to scale...
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.