Marker detection and trajectory generation algorithms for a multicamera based gait analysis system

Date

2001-06-01

Author

Shafiq, MS
Tümer, Sami Turgut
Guler, HC

Metadata

Show full item record

This work is licensed under a Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License.

Item Usage Stats

27
views

0
downloads

The current gait analysis methodology requires tracking of markers placed on the body segments of the lower extremities, by using multiple camera images while tl-ie subject is walking. This study was aimed at the development of application software for the multicamera marker based gait analysis system established at the Middle East Technical University. The main functions of this software are pixel grouping. marker detection and generation of three-dimensional (3D) marker trajectories. The software removes noise and artefacts, and effectively detects the physical markers which may be closely spaced and even overlapped on some camera images. Then, the images in different cameras are matched by utilising the concept of epipolar lines, and 3D co-ordinates of markers are determined for each matching group at every field. Finally, matching of each marker in successive fields is accomplished by employing a set of extrapolation algorithms. thus yielding the required 3D marker trajectories. This paper presents theory, algorithms and implementation of the developed software, as well as an assessment of its performance. In addition to gait analysis for clinical and research purposes. the developed algorithms can find application in sports. 3D computer animation and motion analysis of mechanical constructions.

Subject Keywords

Gait analysis (software), Multicamera marker based motion analysis, Pixel grouping and marker detection, 3D reconstruction; motion tracking, Trajectory generation, Image matching, Epipolar lines

URI

https://hdl.handle.net/11511/47464

Journal

MECHATRONICS

DOI

https://doi.org/10.1016/s0957-4158(00)00026-x

Collections

Department of Mechanical Engineering, Article

Suggestions

OpenMETU
Core

Object Segmentation in Multi-view Video via Color, Depth and Motion Cues Cigla, Cevahir; Alatan, Abdullah Aydın (2009-01-01) In the light of dense depth map estimation, motion estimation and object segmentation, the research on multi-view video (MVV) content has becoming increasingly popular due to its wide application areas in the near future. In this work, object segmentation problem is studied by additional cues due to depth and motion fields. Segmentation is achieved by modeling images as graphical models and performing popular Normalized Cuts method with some modifications. In the graphical models, each node is represented b...
Metric scale and angle estimation in monocular visual odometry with multiple distance sensors Ölmez, Burhan; Tuncer, Temel Engin (2021-10-01) In this paper, a novel approach is presented to estimate the metric scale (MSC) and roll and pitch angles of a platform by using distance sensors in a monocular visual odometry setup. A state-of-the-art visual odometry algorithm Semi-Direct Visual Odometry (SVO) [1] is used to obtain sparse three dimensional (3D) point cloud which is then matched with the measurements obtained from the distance sensors for the estimation process. Metric scale with Kalman (MSCwK) filter approach is presented where the metric...
Anomaly Detection and Activity Perception Using Covariance Descriptor for Trajectories Ergezer, Hamza; Leblebicioğlu, Mehmet Kemal (2016-10-16) In this work, we study the problems of anomaly detection and activity perception through the trajectories of objects in crowded scenes. For this purpose, we propose a novel representation for trajectories via covariance features. Representing trajectories via feature covariance matrices enables us to calculate the distance between the trajectories of different lengths. After setting this proposed representation and calculation of distances between trajectories, anomaly detection is achieved by sparse repres...
Eye tracking in multimodal comprehension of graphs Acartürk, Cengiz (2012-07-31) Eye tracking methodology has been a major empirical research approach for the study of online comprehension processes in reading and scene viewing. The use of eye tracking methodology for the study of diagrammatic representations, however, has been relatively limited so far. The investigation of specific types of diagrammatic representations, such as statistical graphs is even scarce. In this study, we propose eye tracking as an empirical research approach for a systematic analysis of multimodal comprehensi...
VISUAL FIELD TESTING USING FORECASTING AND VIRTUAL REALITY Bülbül, Emre; Akar, Gözde; Department of Electrical and Electronics Engineering (2022-2) The standard method for assessing a patient’s visual field is visual field testing. Many diseases, including glaucoma, which affects more than 80 million people, require visual field testing for monitoring and diagnosis. The testing is done by sending light to fixed locations with different luminosities while the patient is fixating at a certain point, then the sensitivities to light at each location are determined by recording the responses of the patient to seen stimuli. Because of their form and digital ...

Citation Formats

M. Shafiq, S. T. Tümer, and H. Guler, “Marker detection and trajectory generation algorithms for a multicamera based gait analysis system,” MECHATRONICS, pp. 409–437, 2001, Accessed: 00, 2020. [Online]. Available: https://hdl.handle.net/11511/47464.