scholarly journals Tracking Marker Movement for Simplicity of Picture Handling

2019 ◽  
Vol 8 (6S2) ◽  
pp. 710-714
Keyword(s):  
Motion Analysis ◽  
High Speed ◽  
Image Sequence ◽  
Input Image ◽  
Invariant Moments ◽  
Time Motion ◽  
Segmented Image ◽  
Orientation Information ◽  
Position And Orientation ◽  
Moving Parts

High speed machines and mechanisms are often studied from a sequence of images obtained from high speed videography. The use of markers printed or attached on moving parts can greatly assist in tracking the moving parts. We present the design of a marker suitable for planar motion analysis of mechanism. The marker is designed to make the task of image processing computationally less intensive so as to make real time motion analysis practical. Rosenfeld equivalence table algorithm is used to segment the input image. The new geometry of marker facilitates automatic tracking and provides both position and orientation information. Hu invariant moments are used for recognition of the marker shape in the segmented image. Markers are uniquely identified on the basis of a text code that is placed in a designated location with respect to the marker geometry. In this method, the bounding box for the text code is computed. Knowing the orientation of the marker and therefore the text orientation, it is possible to transform the sub- image, containing the text, so that the text is aligned horizontally. This will permit a standard OCR routine to read the text code. The motion of various moving parts in image sequence can be easily inferred once the position and orientation of each of the marker is known

scholarly journals A Time-Motion Analysis of Turns Performed by Highly Ranked Viennese Waltz Dancers

2013 ◽  
Vol 37 (1) ◽  
pp. 55-62 ◽  
Author(s):  
Jerneja Prosen ◽  
Nic James ◽  
Lygeri Dimitriou ◽  
Janez Perš ◽  
Goran Vučković
Keyword(s):  
Computer Vision ◽  
Motion Analysis ◽  
High Speed ◽  
Future Research ◽  
Natural Right ◽  
Video Recordings ◽  
Time Motion ◽  
Tracking Algorithms ◽  
Curved Trajectories ◽  
Movement Parameters

Twenty-four dance couples performing at the 2011 IDSF (International DanceSport Federation) International Slovenia Open were divided into two groups: the first twelve placed couples (top ranked) and the last twelve placed couples (lower ranked). Video recordings were processed automatically using computer vision tracking algorithms under operator supervision to calculate movement parameters. Time and speed of movement were analysed during single natural (right) and reverse (left) turns performed during the Viennese waltz. Both top and lower ranked dancers tended to perform similar proportionate frequencies of reverse (≈ 35%) and natural (≈ 65%) turns. Analysis of reverse turns showed that the top ranked dancers performed less turns on a curved trajectory (16%) than the lower ranked dancers (33%). The top ranked couples performed all turns at similar speeds (F = 1.31, df = 3, p = 0.27; mean = 2.09m/s) all of which were significantly quicker than the lower ranked couples (mean = 1.94m/s), the greatest differences found for reverse turns (12.43% faster for curved trajectories, 8.42% for straight trajectories). This suggests that the ability to maintain a high speed in the more difficult turns, particularly the reverse turns on a curved trajectory, results in the overall dance appearing more fluent as the speed of movement does not fluctuate as much. This aspect of performance needs to be improved by lower ranked dancers if they wish to improve rating of their performance. Future research should determine which factors relate to the speed of turns.

Individualization of Time–Motion Analysis: A Case-Cohort Example

2013 ◽  
Vol 8 (4) ◽  
pp. 456-458 ◽  
Author(s):  
Ric Lovell ◽  
Grant Abt
Keyword(s):  
Motion Analysis ◽  
High Intensity ◽  
High Speed ◽  
Analysis Data ◽  
Soccer Players ◽  
Match Play ◽  
Type Method ◽  
Motion Data ◽  
Time Motion ◽  
External Loads

Purpose:To report the intensity distribution of Premier League soccer players’ external loads during match play, according to recognized physiological thresholds. The authors also present a case in which individualized speed thresholds changed the interpretation of time–motion data.Method:Eight outfield players performed an incremental treadmill test to exhaustion to determine the running speeds associated with their ventilatory thresholds. The running speeds were then used to individualize time–motion data collected in 5 competitive fixtures and compared with commonly applied arbitrary speed zones.Results:Of the total distance covered, 26%, 57%, and 17% were performed at low, moderate, and high intensity, respectively. Individualized time– motion data identified a 41% difference in the high-intensity distance covered between 2 players of the same positional role, whereas the player-independent approach yielded negligible (5–7%) differences in total and high-speed distances covered.Conclusions:The authors recommend that individualized speed thresholds be applied to time–motion-analysis data in synergy with the traditional arbitrary approach.

Limb and thoracolumbosacral kinematics over an upright and parallel spread fence

2019 ◽  
Vol 15 (1) ◽  
pp. 55-67
Author(s):  
V.A. Walker ◽  
S.J. Dyson ◽  
C.A. Tranquille ◽  
J.B. Tacey ◽  
R.C. Murray
Keyword(s):  
Motion Analysis ◽  
High Speed ◽  
Great Variability ◽  
Head Neck

Jumping mechanics have been investigated at take-off, flight and landing, mainly in reference to the limbs with limited evaluation of the thoracolumbosacral region. The objectives of this study were to investigate head, neck, thoracolumbosacral and limb angles in a group of experienced showjumping horses (competing at 1.20-1.60 m) over an upright and parallel spread fence. Ten horses in active showjumping training were recruited (mean 8 years old). High-speed videography (240 Hz) was used to determine thoracolumbosacral kinematic variables of the approach and take-off. No significant differences between the upright and parallel spread fences were observed for any of the variables measured. Individual horse review showed that neck-trunk, thoracolumbar, lumbosacral, coxofemoral angles, take-off distance and speed patterns at take-off were consistent among horses and also repeatable between fence types. Head-neck, stifle and tarsal angles had great variability among horses. The main limitation of this study was that only 2D motion analysis was carried out. In conclusion, analysis of individual horse patterns showed that head, neck, back and limb angles were repeatable over submaximal upright and spread fences in ten horses. Some angles were consistent among horses, but others had individual horse variation.

Time motion analysis of nursing work in ICU, telemetry and medical-surgical units

2017 ◽  
Vol 25 (8) ◽  
pp. 640-646 ◽  
Author(s):  
Elizabeth Schenk ◽  
Ruth Schleyer ◽  
Cami R. Jones ◽  
Sarah Fincham ◽  
Kenn B. Daratha ◽  
...  
Keyword(s):  
Motion Analysis ◽  
Time Motion ◽  
Surgical Units

Peroperative time-motion analysis of diagnostic laparoscopy with laparoscopic ultrasonography

1999 ◽  
Vol 86 (7) ◽  
pp. 951-955 ◽  
Author(s):  
K. T. den Boer ◽  
L. T. de Wit ◽  
J. Dankelman ◽  
D. J. Gouma
Keyword(s):  
Motion Analysis ◽  
Diagnostic Laparoscopy ◽  
Laparoscopic Ultrasonography ◽  
Time Motion

scholarly journals Crack Propagation Velocity Determination by High-speed Camera Image Sequence Processing

2020 ◽  
Author(s):  
Frank Liebold ◽  
Ali A. Heravi ◽  
Oliver Mosig ◽  
Manfred Curbach ◽  
Viktor Mechtcherine ◽  
...  
Keyword(s):  
Crack Propagation ◽  
High Speed ◽  
Vector Fields ◽  
Displacement Vector ◽  
Image Sequence ◽  
High Speed Camera ◽  
Sequence Processing ◽  
Image Sequence Processing ◽  
Propagation Velocities

The determination of crack propagation velocities can provide valuable information for a better understanding of damage processes of concrete. The spatio-temporal analysis of crack patterns developing at a speed of several hundred meters per second is a rather challenging task. In the paper, a photogrammetric procedure for the determination of crack propagation velocities in concrete specimens using high-speed camera image sequences is presented. A cascaded image sequence processing which starts with the computation of displacement vector fields for a dense pattern of points on the specimen’s surface between consecutive time steps of the image sequence chain has been developed. These surface points are triangulated into a mesh, and as representations of cracks, discontinuities in the displacement vector fields are found by a deformation analysis applied to all triangles of the mesh. Connected components of the deformed triangles are computed using region-growing techniques. Then, the crack tips are determined using principal component analysis. The tips are tracked in the image sequence and the velocities between the time stamps of the images are derived. A major advantage of this method as compared to established techniques is in the fact of its allowing for spatio-temporally resolved, full-field measurements rather than point-wise measurements and that information on crack width can be obtained simultaneously. To validate the experimentation, the authors processed image sequences of tests on four compact-tension specimens performed on a split-Hopkinson tension bar. The images were taken by a high-speed camera at a frame rate of 160,000 images per second. By applying to these datasets the image sequence processing procedure as developed, crack propagation velocities of about 800 m/s were determined with a precision in the order of 50 m/s.

scholarly journals 3D Human Motion Tracking and Reconstruction Using DCT Matrix Descriptor

2012 ◽  
Vol 2012 ◽  
pp. 1-11 ◽  
Author(s):  
Alireza Behrad ◽  
Nadia Roodsarabi
Keyword(s):  
3D Reconstruction ◽  
Discrete Cosine Transform ◽  
Motion Tracking ◽  
Image Sequence ◽  
Human Motion ◽  
Human Motion Analysis ◽  
Image Descriptor ◽  
Tracking Process ◽  
Position And Orientation ◽  
Proper Frequency

One of the most important issues in human motion analysis is the tracking and 3D reconstruction of human motion, which utilizes the anatomic points' positions. These points can uniquely define the position and orientation of all anatomical segments. In this work, a new method is proposed for tracking and 3D reconstruction of human motion from the image sequence of a monocular static camera. In this method, 2D tracking is used for 3D reconstruction, which a database of selected frames is used for the correction of tracking process. The method utilizes a new image descriptor based on discrete cosine transform (DCT), which is employed in different stages of the algorithm. The advantage of using this descriptor is the capabilities of selecting proper frequency regions in various tasks, which results in an efficient tracking and pose matching algorithms. The tracking and matching algorithms are based on reference descriptor matrixes (RDMs), which are updated after each stage based on the frequency regions in DCT blocks. Finally, 3D reconstruction is performed using Taylor’s method. Experimental results show the promise of the algorithm.

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