scholarly journals Computer and Physical Modeling for Verification of the Stereo System Calibration Parameters Optimization Results

2021 ◽  
Author(s):  
Vladislav Pinchukov ◽  
Ekaterina Shmatko ◽  
Anton Poroykov ◽  
Artem Bogachev
Keyword(s):  
Physical Modeling ◽  
Video Camera ◽  
Parameters Optimization ◽  
Surface Shape ◽  
Experimental Investigations ◽  
System Calibration ◽  
Video Cameras ◽  
Close Range ◽  
Optimizing Algorithm ◽  
Calibration Parameters

Close-range photogrammetry is widely used to measure surface shapes and diagnose deformation. Usually, a stereo system of video cameras is used to register images of the measured object from several different angles. The surface shape is determined by triangulating a set of 2D points from these images. Triangulation uses the stereo system calibration parameters, which are determined before the experiment. Measurements during conditions with increased vibration loads can lead to a change in the relative position of the cameras of the stereo system (decalibration). This leads to a change in the actual calibration parameters and an increase in the measurement error. The decalibration problem can be solved using multidimensional optimization algorithms. To verify their calculation's results it is proposed to use a computer and physical modeling of decalibration of a video camera stereo system in laboratory conditions. The paper presents the implementation of the optimizing algorithm for the external parameters of a stereo system and the results of its performance during the experimental investigations.

scholarly journals Optimization of the stereo system calibration parameters for photogrammetric measurements in the conditions of field experiments

2021 ◽  
Vol 2127 (1) ◽  
pp. 012029
Author(s):  
V V Pinchukov ◽  
E V Shmatko ◽  
A D Bogachev ◽  
A Yu Poroykov
Keyword(s):  
Field Experiments ◽  
Three Dimensional ◽  
Video Camera ◽  
Surface Shape ◽  
Optical Methods ◽  
System Calibration ◽  
Reprojection Error ◽  
Photogrammetric Method ◽  
Vibration Loads ◽  
Calibration Parameters

Abstract Optical methods for deformation diagnostics and surface shape measurement are often used in scientific research and industry. Most of these methods are based on the triangulation of a set of two-dimensional points from different images corresponding to the three-dimensional points of an object in space. Triangulation is based on the stereo system calibration parameters, which are determined before the experiment. Measurements during conditions with increased vibration loads can lead to a change in the relative position of the cameras of the stereo system (decalibration). This leads to a change in the actual calibration parameters and an increase in the measurement error. This work aims to solve the problem of increasing the measurement accuracy of the photogrammetric method in the case of high vibration loads. For this, it is proposed to use an optimization algorithm for calibration parameters to minimize the reprojection error of three-dimensional points calculated using triangulation. The paper presents the results of a computer simulation of decalibration of a video camera stereo system, an algorithm for optimizing the external parameters of a stereo system, and an assessment of its performance.

scholarly journals Being held to account: Detainees’ perceptions of police body-worn cameras

2018 ◽  
Vol 52 (2) ◽  
pp. 174-192 ◽  
Author(s):  
Murray Lee ◽  
Emmeline Taylor ◽  
Matthew Willis
Keyword(s):  
Use Of Force ◽  
Video Camera ◽  
Activity Increase ◽  
Police Use Of Force ◽  
Video Cameras ◽  
Police Accountability ◽  
The World ◽  
Research Interviews ◽  
Perceptions Of Police ◽  
The Impact

Police organisations across the world are embracing body-worn video camera technology. The justification for this is to enhance public trust in police, provide transparency in policing activity, increase police accountability, reduce conflict between police and public, and to provide a police perspective of incidents and events. However, while the corpus of research into the efficacy and operational practicalities of police use of body-worn video cameras is developing, questions on some elements of their impact remain. The majority of scholarship has hitherto been evaluations focused on the impact of the cameras on police use of force and on the numbers of complaints against the police. Alternatively, this article explores body-worn video cameras from the perspective of police detainees, and specifically, detainees’ perceptions of the capacities of body-worn video cameras to deliver promised increased levels of accountability in policing. The article draws on a survey and research interviews with 907 police detainees across four Australian jurisdictions. While respondents largely support the use of body-worn video cameras they also identify a number of caveats. We conclude by suggesting that there are still impediments in body-worn video cameras to achieving the level of accountability promised by advocates and expected by the respondents.

scholarly journals Videodialysis: a pilot experience of telecare for assisted peritoneal dialysis

2019 ◽  
Vol 33 (1) ◽  
pp. 177-182 ◽  
Author(s):  
Giusto Viglino ◽  
Loris Neri ◽  
Sara Barbieri ◽  
Catia Tortone
Keyword(s):  
Clinical Care ◽  
Video Camera ◽  
Telemedicine System ◽  
Home Video ◽  
Video Cameras ◽  
Psychological Barriers ◽  
Know How ◽  
Remote Station ◽  
Audio Video

Abstract Background We report our experience with Videodialysis (VD), a new telemedicine system created in our Center to overcome physical, cognitive and psychological barriers to PD. Methods We analyzed the technical and clinical care results of VD in the period from 01/01/2009 to 12/31/2018. Results The VD components are: a Remote Station at the patient’s home (video camera, monitor, microphone, technological connectivity box), and a Control Station in the Center (PC with high resolution monitor, webcam, speakerphone) with software that manages 6 audio-video connections simultaneously as well as the Remote Station video cameras. In 2015 a second model of VD was designed to further improve ease of transport, installation, user interface, software functionality and connectivity. VD proved to be highly reliable during 21,000 connections, and easy to use by patients/caregivers without technological skills. During the observational period, 107 patients started PD; of these 77 had barriers to PD: in 15 we overcame the barriers by VD-Assisted PD and in 62 we used other modalities of Assisted PD. During a follow-up of 285 months on VD-Assisted, 5 patients died, 3 were transferred to HD (UFF; leakage; onset of barriers insurmountable with VD), 3 to traditional Assisted PD and 4 remained on VD-Assisted PD. Peritonitis incidence in VD-Assisted PD was 1/84.2 pt/mths, not significantly different to that of the patients not using VD. Sense of confidence was the aspect most highly-appreciated by VD-Assisted PD patients. Conclusions VD-Assisted PD is a reliable, safe system which requires no technological know-how and it is easy to use when self-care is not possible due to physical, cognitive or psychological barriers.

DEVELOPMENT OF MOTION CAPTURE SYSTEM USING DUAL VIDEO CAMERAS FOR THE GAIT DESIGN OF A BIPED ROBOT

2011 ◽  
Vol 08 (02) ◽  
pp. 275-299 ◽  
Author(s):  
JUNG-YUP KIM ◽  
YOUNG-SEOG KIM
Keyword(s):  
Motion Capture ◽  
Human Walking ◽  
Human Gait ◽  
Motion Capture System ◽  
System Calibration ◽  
Walking Gait ◽  
Video Cameras ◽  
Optical Motion ◽  
Optical Motion Capture ◽  
Motion Capture Systems

This paper, describes the development of a motion capture system with novel features for biped robots. In general, motion capture is effectively utilized in the field of computer animation. In the field of humanoid robotics, the number of studies attempting to design human-like gaits by using expensive optical motion capture systems is increasing. The optical motion capture systems used in these studies have involved a large number of cameras because such systems use small-sized ball markers; hence the position accuracy of the markers and the system calibration are very significant. However, since the human walking gait is a simple periodic motion rather than a complex motion, we have developed a specialized motion capture system for this study using dual video cameras and large band-type markers without high-level system calibration in order to capture the human walking gait. In addition to its lower complexity, the proposed capture method requires only a low-cost system and has high space efficiency. An image processing algorithm is also proposed for deriving the human gait data. Finally, we verify the reliability and accuracy of our system by comparing a zero moment point (ZMP) trajectory calculated by the motion captured data with a ZMP trajectory measured by foot force sensors.

Estimation of biases in lidar system calibration parameters using overlapping strips

2010 ◽  
Vol 36 (sup2) ◽  
pp. S335-S354 ◽  
Author(s):  
Ki In Bang ◽  
Ayman Habib ◽  
Ana Kersting
Keyword(s):  
Lidar System ◽  
System Calibration ◽  
Calibration Parameters

Conducting qualitative video research with young children

2018 ◽  
Vol 18 (3) ◽  
pp. 238-247 ◽  
Author(s):  
Kelly Shoecraft ◽  
Bev Flückiger
Keyword(s):  
Young Children ◽  
Video Recording ◽  
Video Camera ◽  
Practical Experience ◽  
Recording Technology ◽  
Content Type ◽  
Video Cameras ◽  
Video Recordings ◽  
Learning Through Play ◽  
Rich Data

Purpose The purpose of this paper is to explore the practical use of video cameras during a study with young children. Design/methodology/approach This paper investigates the use of video cameras in a research study of young children’s utilisation of semiotic tools to communicate during play interactions in a Francophone preschool classroom in British Columbia. It examines the practical in-the-moment decision making of the researcher to support children’s accommodation of the video camera in their play space and ensure rich data were recorded. Findings Children accommodated the video cameras in four distinct ways. These included: curiosity and investigation of the video cameras; engagement in the video recording process with the researcher; incorporation of the video cameras into their play; and disregard of it. Practical implications The findings suggest that video recordings can be an effective method of data collection with young children and provide rich sources of data of the children and their learning through play when the researcher is flexible and responsive and supports children’s accommodation of it. Originality/value Recent advances in recording technology have resulted in the increased use of video recordings as a resource for gathering empirical data in qualitative research. Whilst the ethical considerations related to the use of video recordings as data for analysis in research with young children have been the subject of some discussion (Flewitt, 2005), the practical experience of using video cameras has received less attention.

scholarly journals Mental Health Intergenerational Transmission (MHINT) Process Manual

2021 ◽  
Author(s):  
Ilaria Costantini ◽  
Miguel Angel Cordero ◽  
Amy Campbell ◽  
Romana Burgess ◽  
Kiran Glen ◽  
...  
Keyword(s):  
Mental Health ◽  
Individual Differences ◽  
Intergenerational Transmission ◽  
Video Camera ◽  
Ease Of Use ◽  
Video Cameras ◽  
Independent Variables ◽  
Coding Scheme ◽  
General Rules ◽  
Behaviour Group

Within this manual you will find a descriptive guide to the MHINT coding procedure, general rules for coding, and detailed descriptions of each ‘behaviour group’ with illustrative examples.This manual aims to capture as many relevant behaviours for the evaluation of an interaction as possible, with the underlying hypothesis that individual differences in behaviours can occur subtly and that micro-behaviours are of great importance because they provide specific targets for intervention.The coding scheme can be applied to footage obtained from video cameras installed in the home, those used by an observer, or as in our own research, through wearable headcams and a ‘spy’ photo-frame video camera (Lee et al., 2017). Combined, these methods give the observer the opportunity to code behaviours from different perspectives and, interestingly, to obtain the perspective of the participants. The advantages of this approach are explained in Lee et al. (2017).For ease of use, this manual has been divided into five different sections: perspectives, independent variables, subjects, behaviours, and modifiers. To begin, each of these terms is defined.

scholarly journals Smartphones and Video Cameras: Future Methods for Blood Pressure Measurement

2021 ◽  
Vol 3 ◽  
Author(s):  
Joe Steinman ◽  
Andrew Barszczyk ◽  
Hong-Shuo Sun ◽  
Kang Lee ◽  
Zhong-Ping Feng
Keyword(s):  
Blood Pressure ◽  
Cardiovascular Disease ◽  
Cardiovascular Health ◽  
Blood Pressure Measurement ◽  
Video Camera ◽  
Machine Learning Techniques ◽  
Video Cameras ◽  
Lighting Conditions ◽  
Home Based ◽  
Learning Techniques

Regular blood pressure (BP) monitoring enables earlier detection of hypertension and reduces cardiovascular disease. Cuff-based BP measurements require equipment that is inconvenient for some individuals and deters regular home-based monitoring. Since smartphones contain sensors such as video cameras that detect arterial pulsations, they could also be used to assess cardiovascular health. Researchers have developed a variety of image processing and machine learning techniques for predicting BP via smartphone or video camera. This review highlights research behind smartphone and video camera methods for measuring BP. These methods may in future be used at home or in clinics, but must be tested over a larger range of BP and lighting conditions. The review concludes with a discussion of the advantages of the various techniques, their potential clinical applications, and future directions and challenges. Video cameras may potentially measure multiple cardiovascular metrics including and beyond BP, reducing the risk of cardiovascular disease.

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