scholarly journals Digital and Conventional Film-Based Non-Metric Cameras: A Comparison of Performance in Structural Deformation Surveys

2009 ◽  
Vol 4 (1) ◽  
pp. 11
Author(s):  
Abdullah S. Alsalman
Keyword(s):  
Low Cost ◽  
Research Work ◽  
Digital Camera ◽  
Bundle Adjustment ◽  
Structural Deformation ◽  
Digital Cameras ◽  
Still Image ◽  
Conventional Film ◽  
Control Configuration ◽  
Research Show

This research work presents the results of an experiment concerned with a comparison of the performance of non-metric digital and non-metric film -based cameras for structural deformation surveys. An Olympus OM 10 non-metric camera and a Fujix DS-100 still image digital camera were used to measure the amount of deformation of a model of a light-weight building when under load. For the sake of consistency, the same photogrammetric network design, control configuration and self -calibrating bundle adjustment were used for data evaluation. The results of the research show that digital non-metric cameras are viable ,and possibly accurate , tools for structural deformation studies .Taking into account the obvious advantages of ease of operation , relatively low cost and computer –amenability , the author appeals to surveyors and civil engineers to consider digital cameras in their respective deformation survey studies and practices.

scholarly journals CAMERA CALIBRATION ACCURACY AT DIFFERENT UAV FLYING HEIGHTS

2017 ◽  
Vol XLII-2/W3 ◽  
pp. 595-600 ◽  
Author(s):  
A. R. Yusoff ◽  
M. F. M. Ariff ◽  
K. M. Idris ◽  
Z. Majid ◽  
A. K. Chong
Keyword(s):  
Camera Calibration ◽  
Accuracy Assessment ◽  
Low Cost ◽  
Digital Camera ◽  
Bundle Adjustment ◽  
Digital Cameras ◽  
Mapping Accuracy ◽  
Image Mapping ◽  
Object Distance ◽  
Uav Image

Unmanned Aerial Vehicles (UAVs) can be used to acquire highly accurate data in deformation survey, whereby low-cost digital cameras are commonly used in the UAV mapping. Thus, camera calibration is considered important in obtaining high-accuracy UAV mapping using low-cost digital cameras. The main focus of this study was to calibrate the UAV camera at different camera distances and check the measurement accuracy. The scope of this study included camera calibration in the laboratory and on the field, and the UAV image mapping accuracy assessment used calibration parameters of different camera distances. The camera distances used for the image calibration acquisition and mapping accuracy assessment were 1.5 metres in the laboratory, and 15 and 25 metres on the field using a Sony NEX6 digital camera. A large calibration field and a portable calibration frame were used as the tools for the camera calibration and for checking the accuracy of the measurement at different camera distances. Bundle adjustment concept was applied in Australis software to perform the camera calibration and accuracy assessment. The results showed that the camera distance at 25 metres is the optimum object distance as this is the best accuracy obtained from the laboratory as well as outdoor mapping. In conclusion, the camera calibration at several camera distances should be applied to acquire better accuracy in mapping and the best camera parameter for the UAV image mapping should be selected for highly accurate mapping measurement.

scholarly journals INVESTIGATION INTO THE BEHAVIOUR AND MODELLING OF CHROMATIC ABERRATIONS IN NON-METRIC DIGITAL CAMERAS

2019 ◽  
Vol XLII-2/W18 ◽  
pp. 99-106 ◽  
Author(s):  
D. D. Lichti ◽  
D. Jarron ◽  
M. Shahbazi ◽  
P. Helmholz ◽  
R. Radovanovic
Keyword(s):  
Digital Camera ◽  
Chromatic Aberration ◽  
Bundle Adjustment ◽  
Lens Distortion ◽  
Digital Cameras ◽  
Principal Point ◽  
Common Object ◽  
Chromatic Aberrations ◽  
The Impact ◽  
Orientation Parameters

Abstract. Chromatic aberration in colour digital camera imagery can affect the accuracy of photogrammetric reconstruction. Both longitudinal and transverse chromatic aberrations can be effectively modelled by making separate measurements in each of the blue, green and red colour bands and performing a specialized self-calibrating bundle adjustment. This paper presents the results of an investigation with two aims. The first aim is to quantify the presence of chromatic aberration in two sets of cameras: the six individual cameras comprising a Ladybug5 system, calibrated simultaneously in air; and four GoPro Hero 5 cameras calibrated independently under water. The second aim is to investigate the impacts of imposing different constraints in the self-calibration adjustment. To this end, four different adjustment cases were performed for all ten cameras: independent adjustment of the observations from each colour band; combined adjustment of all colour bands’ observations with common object points; combined adjustment of all colour bands with common object points and common exterior orientation parameters for each colour band triplet; and combined adjustment with common object points and certain common interior orientation parameters. The results show that the Ladybug5 cameras exhibit a small (1-2 pixel) amount of transverse chromatic aberration but no longitudinal chromatic aberration. The GoPro Hero 5 cameras exhibit significant (25 pixel) transverse chromatic aberration as well as longitudinal chromatic aberration. The principal distance was essentially independent of the adjustment case for the Ladybug5, but it was not for the GoPro Hero 5. The principal point position and precision were both affected considerably by adjustment case. Radial lens distortion was invariant to the adjustment case. The impact of adjustment case on decentring distortion was minimal in both cases.

scholarly journals Modelling and Visualization of Three Dimensional Objects Using Inexpensive Digital Cameras

2018 ◽  
Author(s):  
Ismail Elkhrachy
Keyword(s):  
Low Cost ◽  
Three Dimensional ◽  
Point Clouds ◽  
3D Models ◽  
Bundle Adjustment ◽  
Control Points ◽  
Digital Cameras ◽  
Three Dimensional Objects ◽  
Spatial Positioning ◽  
And Control

This paper analyses and evaluate the precision and the accuracy the capability of low-cost terrestrial photogrammetry by using many digital cameras to construct a 3D model of an object. To obtain the goal, a building façade has imaged by two inexpensive digital cameras such as Canon and Pentax camera. Bundle adjustment and image processing calculated by using Agisoft PhotScan software. Several factors will be included during this study, different cameras, and control points. Many photogrammetric point clouds will be generated. Their accuracy will be compared with some natural control points which collected by the laser total station of the same building. The cloud to cloud distance will be computed for different comparison 3D models to investigate different variables. The practical field experiment showed a spatial positioning reported by the investigated technique was between 2-4cm in the 3D coordinates of a façade. This accuracy is optimistic since the captured images were processed without any control points.

scholarly journals Using a Sony Cyber-Shot Digital Camera for Photomicrography

2002 ◽  
Vol 10 (6) ◽  
pp. 10-15
Author(s):  
Gregor Overney
Keyword(s):  
Light Microscopy ◽  
Low Cost ◽  
Digital Camera ◽  
Digital Photography ◽  
Imaging Systems ◽  
Short Paper ◽  
Digital Cameras

Photomicrography is the combination of photography and compound microscopy. Photographers working with compound microscopes are facing many challenges (for an introduction see [1] and [2]). Digital photography offers great advantages, but also adds additional difficulties. Digital cameras have been used in photomicrography for over a decade now. Today, we have access to many excellent consumer-grade digital cameras that are most suitable for low-cost imaging systems for light microscopy. In this short paper, I summarize my experience with the Sony DSC-S70 digital camera, which comes with a nice, large Zeiss lens. (Most of the ideas presented in this paper are also valid for the DSC-S75 and DSC-S85.)

scholarly journals Determination of the Interior Orientation Parameters of a Non-metric Digital Camera for Terrestrial Photogrammetric Applications

2019 ◽  
Vol 19 (2) ◽  
pp. 1-9
Author(s):  
Naa Dedei Tagoe ◽  
S. Mantey
Keyword(s):  
Digital Camera ◽  
Calibration Procedure ◽  
Bundle Adjustment ◽  
Digital Cameras ◽  
Close Range ◽  
Camera Parameters ◽  
The Stability ◽  
Mean Square Errors ◽  
Orientation Parameters

AbstractHigh cost of metric photogrammetric cameras has given rise to the utilisation of non-metric digital cameras to generate photogrammetric products in traditional close range or terrestrial photogrammetric applications. For precision photogrammetric applications, the internal metric characteristics of the camera, customarily known as the Interior Orientation Parameters, need to be determined and analysed. The derivation of these parameters is usually achieved by implementing a bundle adjustment with self-calibration procedure. The stability of the Interior Orientation Parameters is an issue in terms of accuracy in digital cameras since they are not built with photogrammetric applications in mind. This study utilised two photogrammetric software (i.e. Photo Modeler and Australis) to calibrate a non-metric digital camera to determine its Interior Orientation Parameters. The camera parameters were obtained using the two software and the Root Mean Square Errors (RMSE) calculated. It was observed that Australis gave a RMSE of 0.2435 and Photo Modeler gave 0.2335, implying that, the calibrated non-metric digital camera is suitable for high precision terrestrial photogrammetric projects. Keywords: Camera Calibration, Interior Orientation Parameters, Non-Metric Digital Camera

scholarly journals 3D Calibration Test-Field for Digital Cameras Mounted on Unmanned Aerial Systems (UAS)

2018 ◽  
Vol 10 (12) ◽  
pp. 2017 ◽  
Author(s):  
Valeria-Ersilia Oniga ◽  
Norbert Pfeifer ◽  
Ana-Maria Loghin
Keyword(s):  
Near Infrared ◽  
Low Cost ◽  
Digital Camera ◽  
Field Measurements ◽  
Unmanned Aerial Systems ◽  
Test Field ◽  
Digital Cameras ◽  
Self Calibration ◽  
Technological Developments ◽  
Aerial Systems

Due to the large number of technological developments in recent years, UAS systems are now used for monitoring purposes and in projects with high precision demand, such as 3D model-based creation of dams, reservoirs, historical monuments etc. These unmanned systems are usually equipped with an automatic pilot device and a digital camera (photo/video, multispectral, Near Infrared etc.), of which the lens has distortions; but this can be determined in a calibration process. Currently, a method of “self-calibration” is used for the calibration of the digital cameras mounted on UASs, but, by using the method of calibration based on a 3D calibration object, the accuracy is improved in comparison with other methods. Thus, this paper has the objective of establishing a 3D calibration field for the digital cameras mounted on UASs in terms of accuracy and robustness, being the largest reported publication to date. In order to test the proposed calibration field, a digital camera mounted on a low-cost UAS was calibrated at three different heights: 23 m, 28 m, and 35 m, using two configurations for image acquisition. Then, a comparison was made between the residuals obtained for a number of 100 Check Points (CPs) using self-calibration and test-field calibration, while the number of Ground Control Points (GCPs) variedand the heights were interchanged. Additionally, the parameters where tested on an oblique flight done 2 years before calibration, in manual mode at a medium altitude of 28 m height. For all tests done in the case of the double grid nadiral flight, the parameters calculated with the proposed 3D field improved the results by more than 50% when using the optimum and a large number of GCPs, and in all analyzed cases with 75% to 95% when using a minimum of 3 GCP. In this context, it is necessary to conduct accurate calibration in order to increase the accuracy of the UAS projects, and also to reduce field measurements.

scholarly journals PERFORMANCE EVALUATION OF NON-METRIC DIGITAL CAMERA FOR PHOTOGRAMMETRIC APPLICATION

2012 ◽  
Vol 31 (1) ◽  
pp. 23-27 ◽  
Author(s):  
Birutė Ruzgienė
Keyword(s):  
Field Experiments ◽  
Low Cost ◽  
Digital Camera ◽  
Ccd Camera ◽  
Test Field ◽  
Digital Cameras ◽  
Close Range ◽  
Orientation Parameters ◽  
Poor Stability

During the last year amateur low‐cost digital cameras are increasingly expected to contribute to the digital photogrammetry. An important aspect of the suitability of these cameras is determination of their geometrical instability. In order to evaluate amateur digital camera performance, small format, low resolution and low-cost CCD camera have been investigated in two considerations: determining inner orientation parameters at different time and estimating accuracy in test field experiments. The calibration results demonstrate the poor stability of such a digital camera. As a result of the instability, amateur cameras have limited possibilities in close-range photogrammetry. However, the investigated camera under certain limited accuracy requirements can be used for low-accuracy photogrammetric application.

Feasibility study of technology-enabled prevention intervention for children and families (Preprint)

2019 ◽  
Author(s):  
Nikki Theofanopoulou ◽  
Katherine Isbister ◽  
Julian Edbrooke-Childs ◽  
Petr Slovák
Keyword(s):  
Emotion Regulation ◽  
Pilot Study ◽  
Low Cost ◽  
Digital Camera ◽  
Well Being ◽  
Structured Interview ◽  
Object A ◽  
Intervention Delivery ◽  
Parents And Children

BACKGROUND A common challenge within psychiatry and prevention science more broadly is the lack of effective, engaging, and scale-able mechanisms to deliver psycho-social interventions for children, especially beyond in-person therapeutic or school-based contexts. Although digital technology has the potential to address these issues, existing research on technology-enabled interventions for families remains limited. OBJECTIVE The aim of this pilot study was to examine the feasibility of in-situ deployments of a low-cost, bespoke prototype, which has been designed to support children’s in-the-moment emotion regulation efforts. This prototype instantiates a novel intervention model that aims to address the existing limitations by delivering the intervention through an interactive object (a ‘smart toy’) sent home with the child, without any prior training necessary for either the child or their carer. This pilot study examined (i) engagement and acceptability of the device in the homes during 1 week deployments; and (ii) qualitative indicators of emotion regulation effects, as reported by parents and children. METHODS In this qualitative study, ten families (altogether 11 children aged 6-10 years) were recruited from three under-privileged communities in the UK. The RA visited participants in their homes to give children the ‘smart toy’ and conduct a semi-structured interview with at least one parent from each family. Children were given the prototype, a discovery book, and a simple digital camera to keep at home for 7-8 days, after which we interviewed each child and their parent about their experience. Thematic analysis guided the identification and organisation of common themes and patterns across the dataset. In addition, the prototypes automatically logged every interaction with the toy throughout the week-long deployments. RESULTS Across all 10 families, parents and children reported that the ‘smart toy’ was incorporated into children’s emotion regulation practices and engaged with naturally in moments children wanted to relax or calm down. Data suggests that children interacted with the toy throughout the duration of the deployment, found the experience enjoyable, and all requested to keep the toy longer. Child emotional connection to the toy—caring for its ‘well-being’—appears to have driven this strong engagement. Parents reported satisfaction with and acceptability of the toy. CONCLUSIONS This is the first known study investigation of the use of object-enabled intervention delivery to support emotion regulation in-situ. The strong engagement and qualitative indications of effects are promising – children were able to use the prototype without any training and incorporated it into their emotion regulation practices during daily challenges. Future work is needed to extend this indicative data with efficacy studies examining the psychological efficacy of the proposed intervention. More broadly, our findings suggest the potential of a technology-enabled shift in how prevention interventions are designed and delivered: empowering children and parents through ‘child-led, situated interventions’, where participants learn through actionable support directly within family life, as opposed to didactic in-person workshops and a subsequent skills application.

scholarly journals Optical Inspection Systems for Axisymmetric Parts with Spatial 2D Resolution

Symmetry ◽  
2021 ◽  
Vol 13 (7) ◽  
pp. 1218
Author(s):  
Aleksandr Kulchitskiy
Keyword(s):  
Control System ◽  
Optical System ◽  
Measurement Accuracy ◽  
Experimental Studies ◽  
Digital Camera ◽  
Digital Cameras ◽  
Bodies Of Revolution ◽  
Optical Inspection ◽  
Inspection Systems ◽  
Projection Error

The article proposes a solution to the problem of increasing the accuracy of determining the main shaping dimensions of axisymmetric parts through a control system that implements the optical method of spatial resolution. The influence of the projection error of a passive optical system for controlling the geometric parameters of bodies of revolution from the image of its sections, obtained by a digital camera with non-telecentric optics, on the measurement accuracy is shown. Analytical dependencies are derived that describe the features of the transmission of measuring information of a system with non-telecentric optics in order to estimate the projection error. On the basis of the obtained dependences, a method for compensating the projection error of the systems for controlling the geometry of the main shaping surfaces of bodies of revolution has been developed, which makes it possible to increase the accuracy of determining dimensions when using digital cameras with a resolution of 5 megapixels or more, equipped with short-focus lenses. The possibility of implementing the proposed technique is confirmed by the results of experimental studies.

scholarly journals Bionic Birdlike Imaging Using a Multi-Hyperuniform LED Array

Sensors ◽  
2021 ◽  
Vol 21 (12) ◽  
pp. 4084
Author(s):  
Xin-Yu Zhao ◽  
Li-Jing Li ◽  
Lei Cao ◽  
Ming-Jie Sun
Keyword(s):  
Imaging System ◽  
Color Image ◽  
Digital Camera ◽  
Frame Rate ◽  
Digital Cameras ◽  
Structured Illumination ◽  
Pixel Resolution ◽  
Led Array ◽  
Frequency Aliasing ◽  
Imaging Sensors

Digital cameras obtain color information of the scene using a chromatic filter, usually a Bayer filter, overlaid on a pixelated detector. However, the periodic arrangement of both the filter array and the detector array introduces frequency aliasing in sampling and color misregistration during demosaicking process which causes degradation of image quality. Inspired by the biological structure of the avian retinas, we developed a chromatic LED array which has a geometric arrangement of multi-hyperuniformity, which exhibits an irregularity on small-length scales but a quasi-uniformity on large scales, to suppress frequency aliasing and color misregistration in full color image retrieval. Experiments were performed with a single-pixel imaging system using the multi-hyperuniform chromatic LED array to provide structured illumination, and 208 fps frame rate was achieved at 32 × 32 pixel resolution. By comparing the experimental results with the images captured with a conventional digital camera, it has been demonstrated that the proposed imaging system forms images with less chromatic moiré patterns and color misregistration artifacts. The concept proposed verified here could provide insights for the design and the manufacturing of future bionic imaging sensors.

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