1,720,994 research outputs found
A novel camera calibration algorithm based on Kalman filter
No full textIn this paper a novel camera calibration method for video-surveillance applications is presented. The proposed method works on the hypothesis of a fixed TV camera and it is developed in order to minimize the human intervention during the calibration process.
For the application, the proposed algorithm needs the 3D measure of only one point in the scene. Other measures are simulated by using a moving object whose geometry is known and by estimating the 30 position of the object by means of an extended Kalman filter. Experimental results show that the proposed algorithm, other than simplify the
installation step of video-surveillance systems,
considerably improves the accuracy of the calibration with respect to similar algorithms presented in the state of the art
Markovian approach to color image restoration based on space filling curves
No full textA method for color image restoration based on the concept of Markov Random Fields and space-filling curves is presented. This work is a vectorial extension of a scalar deterministic solution for Markov Random Fields (MRFs). The proposed method represents an efficient alternative to the use of the vectorial deterministic solution for MRFs. The application of space filling curve transformation allows one to apply the MRF algorithm to a scalar image with N3 grey levels (typically N = 256). The scalar MRF approach is based on expressing the energy function by means of the Euclidean norm in the vectorial space. This approach implies a high computational load. The new method involves a computational load lower than the vectorial case because the energy function is presented in the scalar space obtained after space filling curve based transformation
Joint video-shot and layer indexing in video-surveillance application
No full textn this paper, a joint video-shot and layer indexing technique is presented with applications to automatic surveillance of indoor environments. A video-based surveillance system has been developed that simultaneously tracks moving objects and detects the presence of abandoned objects. Whenever an abandoned abject is detected, the system is able to determine the video-shot in which a particular object (layer) appears in the guarded environment, from the first frame in which that object enters in the scene to the frame in which the object has been left. The semantic information related on both the dangerous object and the person who left it, allows the system to perform the video-shot detection and indexing tasks. What is important in a video-shot is the information related to the dangerous object present in it. For this reason a video-shot has a two level indexing: the first one is related to the characteristics of the video-shot and the second one is related to the characteristics of a particular layer
Image restoration by means of statistical soft morphology
No full textStatistical soft morphology is an extension of soft morphology which is based on a probabilistic model. It has been first proposed for 1D signal processing. In this paper the 2D case is considered which can be useful to solve image processing restoration problems. Statistical soft morphological operators provide good result in cleaning noise with both morphological and statistical structures, such as speckle noise. Results are presented which show that the proposed method is suitable for processing remote sensing images
Multimedia system for the surveillance of unattended railway stations
No full textIn this paper a multimedia system for surveying remote environments is presented. The goal of the proposed system is to alert the surveillance operator when an abandoned object is detected in waiting rooms of unattended railway stations. The system is based on a monochromatic TV-camera acquiring video data about the surveyed environment; this data are processed at local level to reduce redundancy and only necessary data and images are sent to the remote control centre. The paper is focused on describing two main aspects: 1) image sequence processing 2) channel coding transmission strategies for security issues
Un bozzetto di Francesco Stringa e una precisazione per la galleria della cappella del Palazzo Ducale di Modena
No full textSi presentano alcuni inediti i Francesco Stringa e si fa ulteriore luce sulla decorazione della galleria che portava alla cappella di Palazzo Ducale, a Modena
Signal Restoration by Statistical Soft Morphology
No full textA new set of non linear signal and image processing operators is presented. Their definition is based on the introduction of the statistical properties of Bayesian reconstruction in soft morphological operators. Statistical soft operators represent a trade-off between the noise cleaning properties of statistical morphology and the shape preservation properties of soft morphology. The main characteristic of these operators is the individualization of two parts within each structuring element (SE) according to soft morphology (i.e. "hard" and "soft" SEs), and to define on this basis a probabilistic estimation model which is a generalization of the Statistical Morphology model. Results are presented to show that the statistical soft morphological operators can be considered robust to structured noise, i.e. noise showing both statistical (e.g. additive Gaussian noise) and morphological (e.g. noise with a particular shape) structure. 1 INTRODUCTION The definition of statistical soft morpho..
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
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