121,731 research outputs found
Study Projectile Motion With Different Initial Conditions Using Digital Image
The aim of this research is building algorithms to study projectile motion in tow dimension and tracking the object in sequence frames of digital image . Computer program has written in visual basic language (version 6) depend on mathematical models to detect a motion of object in two–dimensions (2-D)with different initial conditions like initial velocity, the height of object from the earth and the angle of motion, to calculate important variables in motion such as distance, displacement, velocity, speed and the energy (kinetic and potential). Color digital images of type (bmp) and (RGB) color model were used in the study for easy handling them, after determining the center of the image on the x-axis, and y-axis and tracking movement on the basis of the center, and the results were expected to conform to the movement of the body. Key words: Projectile, Motion, Digital Image
Study Projectile Motion With Different Initial Conditions Using Digital Image
The aim of this research is building algorithms to study projectile motion in tow dimension and tracking the object in sequence frames of digital image . Computer program has written in visual basic language (version 6) depend on mathematical models to detect a motion of object in two–dimensions (2-D)with different initial conditions like initial velocity, the height of object from the earth and the angle of motion, to calculate important variables in motion such as distance, displacement, velocity, speed and the energy (kinetic and potential). Color digital images of type (bmp) and (RGB) color model were used in the study for easy handling them, after determining the center of the image on the x-axis, and y-axis and tracking movement on the basis of the center, and the results were expected to conform to the movement of the body. Key words: Projectile, Motion, Digital Image
TennisSense: a platform for extracting semantic information from multi-camera tennis data
In this paper, we introduce TennisSense, a technology platform for the digital capture, analysis and retrieval of tennis training and matches. Our algorithms for extracting useful metadata from the overhead court camera are described and evaluated. We track the tennis ball using motion images for ball candidate detection and then link ball candidates into locally linear tracks. From these tracks we can infer when serves and rallies take place. Using background subtraction and hysteresis-type blob tracking, we track the tennis players positions. The performance of both modules is evaluated using ground-truthed data. The extracted metadata provides valuable information for indexing and efficient browsing of hours of multi-camera tennis footage and we briefly illustrative how this data is used by our tennis-coach playback interface
Automated visual tracking for studying the ontogeny of zebrafish swimming
The zebrafish Danio rerio is a widely used model organism in studies of genetics, developmental biology, and recently, biomechanics. In order to quantify changes in swimming during all stages of development, we have developed a visual tracking system that estimates the posture of fish. Our current approach assumes planar motion of the fish, given image sequences taken from a top view. An accurate geometric fish model is automatically designed and fit to the images at each time frame. Our approach works across a range of fish shapes and sizes and is therefore well suited for studying the ontogeny of fish swimming, while also being robust to common environmental occlusions. Our current analysis focuses on measuring the influence of vertebra development on the swimming capabilities of zebrafish. We examine wild-type zebrafish and mutants with stiff vertebrae (stocksteif) and quantify their body kinematics as a function of their development from larvae to adult (mutants made available by the Hubrecht laboratory, The Netherlands). By tracking the fish, we are able to measure the curvature and net acceleration along the body that result from the fish's body wave. Here, we demonstrate the capabilities of the tracking system for the escape response of wild-type zebrafish and stocksteif mutant zebrafish. The response was filmed with a digital high-speed camera at 1500 frames s–1. Our approach enables biomechanists and ethologists to process much larger datasets than possible at present. Our automated tracking scheme can therefore accelerate insight in the swimming behavior of many species of (developing) fish
Motion Tracking With Web Camera Images Based On Spatial Properties
Machine Vision provides a cheap and flexible mean of tracking
objects in motion when implemented by a web Camera. The low resolution
digital images, capturing the different instances of the scene of object in
motion yields information which can be used to lay a historical track of the
object.
The implementation of such a system. involved the separation of the
objects from the background using threshold segmentation techniques.
Although it accepted the variation of natural lighting, it assumed that the
background was lighter than the objects. By that method, the objects which
have the potential to move, were separated from the stationary background.The segmentation scheme implemented was a robust automated
scheme, and form the preprocessing stage of the whole system
Correspondence Estimation from Non-Rigid Motion Information
The DIET (Digital Image Elasto Tomography) system is a novel approach to screen for breast cancer using only optical imaging information of the surface of a vibrating breast. 3D tracking of skin surface motion without the requirement of external markers is desirable. A novel approach to establish point correspondences using pure skin images is presented here. Instead of the intensity, motion is used as the primary feature, which can be extracted using optical flow algorithms. Taking sequences of multiple frames into account, this motion information alone is accurate and unambiguous enough to allow for a 3D reconstruction of the breast surface. Two approaches, direct and probabilistic, for this correspondence estimation are presented here, suitable for different levels of calibration information accuracy. Reconstructions show that the results obtained using these methods are comparable in accuracy to marker-based methods while considerably increasing resolution. The presented method has high potential in optical tissue deformation and motion sensing
Real-time myocardial landmark tracking for MRI-guided cardiac radio-ablation using Gaussian Processes
The high speed of cardiorespiratory motion introduces a unique challenge for
cardiac stereotactic radio-ablation (STAR) treatments with the MR-linac. Such
treatments require tracking myocardial landmarks with a maximum latency of 100
ms, which includes the acquisition of the required data. The aim of this study
is to present a new method that allows to track myocardial landmarks from few
readouts of MRI data, thereby achieving a latency sufficient for STAR
treatments. We present a tracking framework that requires only few readouts of
k-space data as input, which can be acquired at least an order of magnitude
faster than MR-images. Combined with the real-time tracking speed of a
probabilistic machine learning framework called Gaussian Processes, this allows
to track myocardial landmarks with a sufficiently low latency for cardiac STAR
guidance, including both the acquisition of required data, and the tracking
inference. The framework is demonstrated in 2D on a motion phantom, and in vivo
on volunteers and a ventricular tachycardia (arrhythmia) patient. Moreover, the
feasibility of an extension to 3D was demonstrated by in silico 3D experiments
with a digital motion phantom. The framework was compared with template
matching - a reference, image-based, method - and linear regression methods.
Results indicate an order of magnitude lower total latency (<10 ms) for the
proposed framework in comparison with alternative methods. The
root-mean-square-distances and mean end-point-distance with the reference
tracking method was less than 0.8 mm for all experiments, showing excellent
(sub-voxel) agreement. The high accuracy in combination with a total latency of
less than 10 ms - including data acquisition and processing - make the proposed
method a suitable candidate for tracking during STAR treatments
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