1,894 research outputs found
New Approach for Detecting and Tracking a Moving Object
This article presents the implementation of a tracking system for a moving target using a fixed camera. The objective of this work is the ability to detect a moving object and locate their positions. In picture processing, tracking moving objects in a known or unknown environment is commonly studied. It is based on invariance properties of objects of interest. The invariance can affect the geometry of the scene or the objects. The proposed approach is composed of several steps; the first is the extraction of points of interest in the current image. Then, these points will be tracked in the following image by using techniques for calculating the optical flow. After this step, the static points will be removed to focus on moving objects, That is to say, there is only the characteristic points belonging to moving objects. Now, to detect moving targets using images of the video, the background is first extracted from the successive images. In our approach, a method of the average values of every pixel has been developed for modeling background. The last step which stays before switching to tracking moving object is the segmentation which allows identifying every moving object. And by using the characteristic points in the previous steps
Dynamics of polymeric solutions in complex kinematics bulk and free surface flows: Multiscale/Continuum simulations and experimental studies
While rheological and microstructural complexities have posed tremendous challenges to researchers in developing first principles models and simulation techniques that can accurately and robustly predict the dynamical behaviour of polymeric flows, the past two decades have offered several significant advances towards accomplishing this goal. These accomplishments include: (1). Stable and accurate formulation of continuum-level viscoelastic constitutive models and their efficient implementation using operator splitting methods to explore steady and transient flows in complex geometries, (2). Prediction of rheology of polymer solutions and melts based on micromechanical models as well as highly parallel self-consistent multiscale simulations of non-homogeneous flows. The main objective of this study is to leverage and build upon the aforementioned advances to develop a quantitative understanding of the flow-micro-structure coupling mechanisms in viscoelastic polymeric fluids and in turn predict, consistent with experiments, their essential macroscopic flow properties e.g. frictional drag, interface shape, etc. To this end, we have performed extensive continuum and multiscale flow simulations in several industrially relevant bulk and free surface flows. The primary motivation for the selection of the specific flow problems is based on their ability to represent different deformation types, and the ability to experimentally verify the simulation results as well as their scientific and industrial significance
Filtering of image sequences: on line edge detection and motion reconstruction
L'argomento della Tesi riguarda lĂelaborazione di sequenze di immagini, relative ad una
scena in cui uno o piË oggetti (possibilmente deformabili) si muovono e acquisite da un
opportuno strumento di misura. A causa del processo di misura, le immagini sono corrotte da
un livello di degradazione. Si riporta la formalizzazione matematica dellĂinsieme delle
immagini considerate, dellĂinsieme dei moti ammissibili e della degradazione introdotta dallo
strumento di misura. Ogni immagine della sequenza acquisita ha una relazione con tutte le
altre, stabilita dalla legge del moto della scena. LĂidea proposta in questa Tesi Ă quella di
sfruttare questa relazione tra le diverse immagini della sequenza per ricostruire grandezze di
interesse che caratterizzano la scena.
Nel caso in cui si conosce il moto, lĂinteresse Ă quello di ricostruire i contorni dellĂimmagine
iniziale (che poi possono essere propagati attraverso la stessa legge del moto, in modo da
ricostruire i contorni della generica immagine appartenente alla sequenza in esame), stimando
lĂampiezza e del salto del livello di grigio e la relativa localizzazione.
Nel caso duale si suppone invece di conoscere la disposizione dei contorni nellĂimmagine
iniziale e di avere un modello stocastico che descriva il moto; lĂobiettivo Ă quindi stimare i
parametri che caratterizzano tale modello.
Infine, si presentano i risultati dellĂapplicazione delle due metodologie succitate a dati reali
ottenuti in ambito biomedicale da uno strumento denominato pupillometro. Tali risultati sono
di elevato interesse nellĂottica di utilizzare il suddetto strumento a fini diagnostici
Spatiotemporal Saliency Detection: State of Art
Saliency detection has become a very prominent subject for research in recent time. Many techniques has been defined for the saliency detection.In this paper number of techniques has been explained that include the saliency detection from the year 2000 to 2015, almost every technique has been included.all the methods are explained briefly including their advantages and disadvantages. Comparison between various techniques has been done. With the help of table which includes authors name,paper name,year,techniques,algorithms and challenges. A comparison between levels of acceptance rates and accuracy levels are made
Light-sheet microscopy: a tutorial
This paper is intended to give a comprehensive review of light-sheet (LS) microscopy from an optics perspective. As such, emphasis is placed on the advantages that LS microscope configurations present, given the degree of freedom gained by uncoupling the excitation and detection arms. The new imaging properties are first highlighted in terms of optical parameters and how these have enabled several biomedical applications. Then, the basics are presented for understanding how a LS microscope works. This is followed by a presentation of a tutorial for LS microscope designs, each working at different resolutions and for different applications. Then, based on a numerical Fourier analysis and given the multiple possibilities for generating the LS in the microscope (using Gaussian, Bessel, and Airy beams in the linear and nonlinear regimes), a systematic comparison of their optical performance is presented. Finally, based on advances in optics and photonics, the novel optical implementations possible in a LS microscope are highlighted.Peer ReviewedPostprint (published version
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