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.
In this paper, we formulate the feature clustering problem for vehicle detection and tracking as a general MAP problem and solve it using MCMC. The proposed approach exhibits two advantages over existing methods: general Bayesian model can handle arbitrary objective functions and MCMC guarantees global optimal solution. Our algorithm is validated on real-world traffic video sequences, and is shown...
Many object tracking methods based on Adaptive Appearance Models (online learning methods) have been developed in recent years. One problem that can be found with these methods is how to learn variations in object appearance without errors in the image sequence. This paper introduces a novel method, in which a solution to remove learning errors by using an offline learning is proposed; in addition,...
The problem of estimating the three-dimensional (3D) geometry of an object from a sequence of images obtained at different focus settings is called shape from focus (SFF). The conventional SFF methods apply focus measure operator at each pixel using neighboring pixels in the same image frame. However, for an object with complex geometry, such methods cannot compute accurate focus level of a pixel,...
In conventional focus measures, focus values are locally aggregated to suppress the noise and to obtain better depth maps. However, this enlarges the difference between focus values of two consecutive frames which results in inaccurate shape. In this paper, we propose a nonparametric approach for 3D shape from image focus by applying an unsupervised formulation of kernel regression estimate. The focus...
Dynamic MRI sequences are clinically used for the assessment of pelvic floor disorders. The organs complex movements are observed in the median sagittal plane. An objective characterization of the deformations that occur could allow an estimation of the similarity of the sequences. This quantification could pave the way to sequence classification or pathological grade determination as well as to the...
In this paper, we present a novel parallel implementation of Active Shape Model (ASM) on GPU for massive facial feature extractions in video or image sequence. With the Compute Unified Device Architecture (CUDA)-enabled GPU, the acceleration is significant and reported a 48 times performance boost comparing to a CPU implementation. We adopt the hardware built-in bilinear interpolation of texture to...
This paper proposes a novel gait recognition method based on fast shape matching algorithm. First, we propose a simple but effective gait cycle estimating method and analyze the periodic property of gait sequences. Each frame in the sequence is assigned a phase. Those frames with the same phase are averaged to clean noises. As a result, the original long sequence with dozens of frames is simply represented...
With the proliferation of small-display mobile devices, the video sequences which are captured for normal size screen, may give small-display viewers uncomfortable experience, especially for some kinds of sports videos. We focus on soccer video, and propose to establish a saliency binary map and several character rules to detect the ball and decide the region-of-interest accordingly. Experimental...
This paper presents a novel technique for depth map estimation using a sequence of images acquired at varying focus. In depth map estimation noise, illumination variations and types of extracted features significantly affect the performance of a focus measure. This paper proposes the use of SUSAN operator, to extract features, because of its structure preserving noise filtering which plays a pivotal...
In this paper, we present a new posture classification system to analyze different human activities directly from video sequence. For well recognizing each posture of an activity, we propose an adaptation of Radon transform called R-transform, which is invariant to common geometrical transformations, to represent low-level features. The advantage of the R transform lies in its low computational complexity...
Action recognition is a challenging problem in video analytics due to event complexity, variations in imaging conditions, and intra- and inter-individual action-variability. Central to these challenges is the way one models actions in video, i.e., action representation. In this paper, an action is viewed as a temporal sequence of local shape-deformations of centroid-centered object silhouettes, i...
Bolus tracking of contrast agent with MRI is a well established technique for measurement of local cerebral hemodynamic parameters flow, volume and mean transit time. When performed on a voxel-by-voxel basis, it allows development of hemodynamic parameter maps useful for assessment of ischemic damage following stroke and tumor characterization in cancer. The analysis of the acquired dynamic data requires...
Nerve cell segmentation is important for better understanding of the connections between broken nerves. In this paper, we propose a registration-based segmentation to improve the segmentation from a series of microscopic image sequence. A global iterative closest point (ICP) registration is first employed to find the corresponding cells between neighboring frames. Then a local ICP registration is...
Today, elder care demands a greater degree of versatility in healthcare. Automatic monitoring devices and sensors are under development to help senior citizens achieve greater autonomy, and, as situations arise, alert healthcare providers. In this paper, we study gait patterns based on extracted silhouettes from image sequences. Three features are investigated through two different image capture perspectives:...
Pain is generally measured by patient self-report, normally via verbal communication. However, if the patient is a child or has limited ability to communicate (i.e. the mute, mentally impaired, or patients having assisted breathing) self-report may not be a viable measurement. In addition, these self-report measures only relate to the maximum pain level experienced during a sequence so a frame-by-frame...
This paper proposes a system for people trajectory shape analysis by exploiting a statistical approach which accounts for sequences of both directional (the directions of the trajectory) and linear (the speeds) data. A semi-directional distribution (AWLG - Approximated Wrapped and Linear Gaussian) is used with a mixture to find main directions and speeds. A variational version of the mutual information...
We present in this paper a human detection system for the analysis of video sequences. We perform first a foreground detection with a Gaussian background model. A tracking step based on connected components analysis combined with feature points tracking allows to collect information on 2D displacements of moving objects in the image plane and so to improve the performance of our classifier. A classification...
A mura detection approach based on the difference accumulation and background estimation is proposed to detect mura in the thin film transistor liquid crystal display (TFT-LCD) images. We were motivated by wavelet transform to derive a multi-resolution method for accelerating the detecting speed of background estimation. While the visibility of mura depends on inspecting angles and online environmental...
In this paper, we propose a two-level integrated model for accurate 3D tracking of rigid head motion and non-rigid facial animation. At the lowest level, the 2D shape of facial features is robustly extracted using a regularized shape model and a cascade multi-stage algorithm. At the highest level, we estimate both the facial animation and 3D pose parameters via minimizing an energy function comprising...
We present an efficient algorithm for fitting a morphable model to an image sequence. It is built on a projective geometry formulation of perspective projection, which results in a linear mapping from 3D shape to the projective plane, and a factorisation of this mapping into matrices that can be partially computed off-line. This algorithm can cope with full 360 degrees object rotation and linear deformations...
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.