Evaluation of Open-Source and Pre-Trained Deep Convolutional Neural Networks Suitable for Player Detection and Motion Analysis in Squash

In sport science, athlete tracking and motion analysis are essential for monitoring and optimizing training programs, with the goal of increasing success in competition and preventing injury. At present, contact-free, camera-based, multi-athlete detection and tracking have become a reality, mainly d...

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Main Authors: Christopher Brumann, Markus Kukuk, Claus Reinsberger
Format: Article
Language:English
Published: MDPI AG 2021-07-01
Series:Sensors
Subjects:
Online Access:https://www.mdpi.com/1424-8220/21/13/4550
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author Christopher Brumann
Markus Kukuk
Claus Reinsberger
author_facet Christopher Brumann
Markus Kukuk
Claus Reinsberger
author_sort Christopher Brumann
collection DOAJ
description In sport science, athlete tracking and motion analysis are essential for monitoring and optimizing training programs, with the goal of increasing success in competition and preventing injury. At present, contact-free, camera-based, multi-athlete detection and tracking have become a reality, mainly due to the advances in machine learning regarding computer vision and, specifically, advances in artificial convolutional neural networks (CNN), used for human pose estimation (HPE-CNN) in image sequences. Sport science in general, as well as coaches and athletes in particular, would greatly benefit from HPE-CNN-based tracking, but the sheer amount of HPE-CNNs available, as well as their complexity, pose a hurdle to the adoption of this new technology. It is unclear how many HPE-CNNs which are available at present are ready to use in out-of-the-box inference to squash, to what extent they allow motion analysis and if detections can easily be used to provide insight to coaches and athletes. Therefore, we conducted a systematic investigation of more than 250 HPE-CNNs. After applying our selection criteria of open-source, pre-trained, state-of-the-art and ready-to-use, five variants of three HPE-CNNs remained, and were evaluated in the context of motion analysis for the racket sport of squash. Specifically, we are interested in detecting player’s feet in videos from a single camera and investigated the detection accuracy of all HPE-CNNs. To that end, we created a ground-truth dataset from publicly available squash videos by developing our own annotation tool and manually labeling frames and events. We present heatmaps, which depict the court floor using a color scale and highlight areas according to the relative time for which a player occupied that location during matchplay. These are used to provide insight into detections. Finally, we created a decision flow chart to help sport scientists, coaches and athletes to decide which HPE-CNN is best for player detection and tracking in a given application scenario.
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spelling doaj.art-761daedae2a949a68c85c13d48aaedce2023-11-22T02:50:59ZengMDPI AGSensors1424-82202021-07-012113455010.3390/s21134550Evaluation of Open-Source and Pre-Trained Deep Convolutional Neural Networks Suitable for Player Detection and Motion Analysis in SquashChristopher Brumann0Markus Kukuk1Claus Reinsberger2Department of Computer Science, University of Applied Sciences and Arts Dortmund, 44139 Dortmund, GermanyDepartment of Computer Science, University of Applied Sciences and Arts Dortmund, 44139 Dortmund, GermanyPaderborn University, Department of Exercise and Health, Institute of Sports Medicine, 33098 Paderborn, GermanyIn sport science, athlete tracking and motion analysis are essential for monitoring and optimizing training programs, with the goal of increasing success in competition and preventing injury. At present, contact-free, camera-based, multi-athlete detection and tracking have become a reality, mainly due to the advances in machine learning regarding computer vision and, specifically, advances in artificial convolutional neural networks (CNN), used for human pose estimation (HPE-CNN) in image sequences. Sport science in general, as well as coaches and athletes in particular, would greatly benefit from HPE-CNN-based tracking, but the sheer amount of HPE-CNNs available, as well as their complexity, pose a hurdle to the adoption of this new technology. It is unclear how many HPE-CNNs which are available at present are ready to use in out-of-the-box inference to squash, to what extent they allow motion analysis and if detections can easily be used to provide insight to coaches and athletes. Therefore, we conducted a systematic investigation of more than 250 HPE-CNNs. After applying our selection criteria of open-source, pre-trained, state-of-the-art and ready-to-use, five variants of three HPE-CNNs remained, and were evaluated in the context of motion analysis for the racket sport of squash. Specifically, we are interested in detecting player’s feet in videos from a single camera and investigated the detection accuracy of all HPE-CNNs. To that end, we created a ground-truth dataset from publicly available squash videos by developing our own annotation tool and manually labeling frames and events. We present heatmaps, which depict the court floor using a color scale and highlight areas according to the relative time for which a player occupied that location during matchplay. These are used to provide insight into detections. Finally, we created a decision flow chart to help sport scientists, coaches and athletes to decide which HPE-CNN is best for player detection and tracking in a given application scenario.https://www.mdpi.com/1424-8220/21/13/4550racket sportssports analysisvideo trackinghuman pose estimation
spellingShingle Christopher Brumann
Markus Kukuk
Claus Reinsberger
Evaluation of Open-Source and Pre-Trained Deep Convolutional Neural Networks Suitable for Player Detection and Motion Analysis in Squash
Sensors
racket sports
sports analysis
video tracking
human pose estimation
title Evaluation of Open-Source and Pre-Trained Deep Convolutional Neural Networks Suitable for Player Detection and Motion Analysis in Squash
title_full Evaluation of Open-Source and Pre-Trained Deep Convolutional Neural Networks Suitable for Player Detection and Motion Analysis in Squash
title_fullStr Evaluation of Open-Source and Pre-Trained Deep Convolutional Neural Networks Suitable for Player Detection and Motion Analysis in Squash
title_full_unstemmed Evaluation of Open-Source and Pre-Trained Deep Convolutional Neural Networks Suitable for Player Detection and Motion Analysis in Squash
title_short Evaluation of Open-Source and Pre-Trained Deep Convolutional Neural Networks Suitable for Player Detection and Motion Analysis in Squash
title_sort evaluation of open source and pre trained deep convolutional neural networks suitable for player detection and motion analysis in squash
topic racket sports
sports analysis
video tracking
human pose estimation
url https://www.mdpi.com/1424-8220/21/13/4550
work_keys_str_mv AT christopherbrumann evaluationofopensourceandpretraineddeepconvolutionalneuralnetworkssuitableforplayerdetectionandmotionanalysisinsquash
AT markuskukuk evaluationofopensourceandpretraineddeepconvolutionalneuralnetworkssuitableforplayerdetectionandmotionanalysisinsquash
AT clausreinsberger evaluationofopensourceandpretraineddeepconvolutionalneuralnetworkssuitableforplayerdetectionandmotionanalysisinsquash