DSLR Camera Research Articles

ACCURATE VEHICLE SPEED ESTIMATION FROM MONOCULAR CAMERA FOOTAGE

Abstract. A workflow is devised in this paper by which vehicle speeds are estimated semi-automatically via fixed DSLR camera. Deep learning algorithm YOLOv2 was used for vehicle detection, while Simple Online Realtime Tracking (SORT) algorithm enabled for tracking of vehicles. Perspective projection and scale factor were dealt with by remotely mapping corresponding image and real-world coordinates through a homography. The ensuing transformation of camera footage to British National Grid Coordinate System, allowed for the derivation of real-world distances on the planar road surface, and subsequent simultaneous vehicle speed estimations. As monitoring took place in a heavily urbanised environment, where vehicles frequently change speed, estimations were determined consecutively between frames. Speed estimations were validated against a reference dataset containing precise trajectories from a GNSS and IMU equipped vehicle platform. Estimations achieved an average root mean square error and mean absolute percentage error of 0.625 m/s and 20.922 % respectively. The robustness of the method was tested in a real-world context and environmental conditions.

Calibration of digital compact cameras for sky quality measures

This work presents the possibility of using the extremely popular compact digital cameras of smartphones or action cameras to perform sky photometry. The newest generation of these devices allows to save raw images. They are not as good as digital single-lens reflex camera, in particular in terms of sensitivity, noise and pixel depth (10 bit versus 12 bit or more), but they have the advantage of being extremely widespread on the population and relatively cheap. These economical digital compact cameras work with an electronic shutter, it overcomes the consumption of mechanics and allows to gather images for long time. The work uses a simple calibration method to transfer raw data from the proprietary RGB color space to the standard CIE 1931 color space. It allows the measurement of sky luminance in cd m−2 with an expected uncertainty of about 20%. Furthermore, the colorimetric calibration allows to know the correlated color temperature of a portion of the sky, it can help the identification of the kind of polluting sources. Aiming at better clarifying the performances of calibrated digital compact cameras, a comparison with a calibrated DSLR camera is presented in outdoor situations showing a good agreement both for luminance and color temperature measurements.

A Cross-Sectional Survey to Evaluate Acquaintance about Dental Photography among Dental Students in Daily Clinical Practice

Background: In today’s world of digital dentistry, dental photography plays an important role as multilevel significance and represents the synonym of contemporary dentistry. Thus, we aimed at evaluating the acquaintance of practice, opportunity and morals of dental photography in everyday practice among undergraduate dental students.Design and Methods: The current research was an observational cross-sectional study. Total 233 students participated; each was given questionnaire consisted of three parts covering the following aspects: questions 1 to 3 on the practice of dental photography, questions 4 to 7 on morals in dental photography and question 8 to 11 on opportunities of dental photography. The answers were tabulated and statistically analysed and association with the factors were tested for significance using Chi-square tests, and P<0.05 was considered statistically significant.Results: The total response rate was 86%. Among the 201 respondents, 100 were males and 101 females; 96% male students were taking photographs and 93% females were taking photographs, on regular basis. Phone cameras (41.3%) were the most commonly used device followed by DSLR cameras. Surveyed students mentioned patient education (53.2%) as most needed requirement for taking photographs, followed by treatment planning (49.8%) and monitoring of the treatment outcome (34.3%). Ninety-one percent of students feel that there is an opportunity for advancement in dental photography techniques.Conclusions: The participants aware of dental photography, but they require detail insight on proper capturing of photographs and morals, with regards to confidentiality of the patient and patient consent.Significance for public healthTaking pictures in dentistry is not only capturing an object. It is an art where clinician should be able to capture the details of the concern area and the image should be self-explanatory. Especially taking an intra-oral picture requires proper equipment’s, correct camera settings, flashes, reflectors, and mirrors etc, these all are not taught in routine dental courses. Thus, each dentist needs additional training and knowledge in this field.

The Comparison of Smile Aesthetic of Males and Females Based on Buccal Corridor and Smile Arc

In performing the orthodontic treatments, patients aim to improve their smile esthetical features which are influenced by the position, size, shape, and color of teeth. However, in recent decades, several aesthetical features that have been studied are buccal corridor, smile arc, incisor display, and gingival display. In this study, 32 subjects composed of 16 males and 16 females were photographed from the front-site by using a DSLR camera within smiling states. Smile arc and buccal corridor measurements were performed via Corel Draw 12 program. The extra broad and broad characteristics were found in male subjects which were 31.2% and 18.8% respectively, while the female subjects had a higher broad proportion of 43.7% and extra broad for 6.3%. The smile arc features in male subjects were found were straight smile (34.4%) and consonant smile (15.6%), in contrast, the percentage of the female students had a higher consonant smile (31.3%) than straight smile (18.8%). This study confirmed similar findings regarding the domination of the buccal corridor broad in the female population, whereas the extra broad is dominated by males. By contrast, the smile arc consonant is dominated by females, while the straight feature is dominated by males.

Erratum to: Discolouration of polyamide microcrystalline denture base plates after exposure to filter cigarette smoke [Padjadjaran Journal of Dentistry. 2020;32(2):1-5.

Introduction: Denture users with smoking habit often complain about colour changes in their dentures, especially on the base part. Polyamide microcrystalline is a thermoplastic denture base material and does not undergo many colour changes. The purpose of this study was to analyse the effect of filter cigarettes smoke exposure on the colour of polyamide microcrystalline materials. Methods: This study used posttest only control group design — plate-shaped sample with a size of 2 x 2 x 0.5 cm3. Nine samples as controls were immersed without exposure to the cigarette smoke, and 9 samples were immersed in artificial saliva with exposure to the filter cigarette smoke by six cycles, where one cycle was in the form of smoke exposure from one cigarette at 30-minute intervals. Cigarette exposure lasts for 21 days using a smoking simulation tool. Every seven days of exposure, colours were evaluated using a DSLR camera. The photos were then analysed with Adobe™ Photoshop in the CIELab colour space. The results were analysed afterwards by a one-way ANOVA variant test, and advance difference tests were analysed using a Post-Hoc test. Results: There was a significant colour change after exposure (p &lt; 0.05), but the control group did not experience discolouration. The highest rate of colour change occurred in the second week, while in the third week the colour changes still occurred but tend to be stable. Conclusion: Exposure to the filter cigarette smoke changes the colour of polyamide microcrystalline denture base.

Detection of polarization neutral points in observations of the combined corona and sky during the 21 August 2017 total solar eclipse.

We report the results of polarimetric observations of the total solar eclipse of 21 August 2017 from Rexburg, Idaho (USA). We use three synchronized DSLR cameras with polarization filters oriented at 0°, 60°, and 120° to provide high-dynamic-range RGB polarization images of the corona and surrounding sky. We measure tangential coronal polarization and vertical sky polarization, both as expected. These observations provide detailed detections of polarization neutral points above and below the eclipsed Sun where the coronal polarization is canceled by the sky polarization. We name these special polarization neutral points after Minnaert and Van de Hulst.

Predicting compressive strength of CRM samples using Image processing and ANN

Quality of concrete is majorly ascertained through its compressive strength which has a significant role in the stability of concrete structures. In this study, artificial neural network (ANN) and image processing (IP) techniques were used to predict the concrete compressive strength (fc ) with cement replacement material (CRM), i.e., Fly Ash (FA) and Silica Fumes (SF). 18 concrete cylinders were cast with different mix ratios and with different % of CRM. Half of them were tested for compression strength in the laboratory and remaining cylinders were cut into three slices each, for prediction of compressive strength through the proposed technique. Images were obtained using a DSLR camera under defined conditions to extract the features. Based on the extracted features, ANN modelling was performed for predicting fc . A comparison of experimental results and ANN results (R = 0.9865) proved ANN models can be used as a prediction tool for compressive strength of concrete.

Investigation on the Applicability of Defocus Blur Variations to Depth Calculation Using Target Sheet Images Captured by a DSLR Camera

Investigation on the Applicability of Defocus Blur Variations to Depth Calculation Using Target Sheet Images Captured by a DSLR Camera

AB0735 SEVERITY OF NAIL PSORIASIS SCORE (SNAPS) DEMONSTRATES LONGITUDINAL CONSTRUCT VALIDITY AGAINST THE MODIFIED NAIL PSORIASIS SEVERITY INDEX (mNAPSI) IN AN OBSERVATIONAL COHORT OF PATIENTS WITH PSORIATIC ARTHRITIS

Background:Longitudinal observational data on psoriatic nail dystrophy is scarce, in part due to the lack of a validated outcome measure that is feasible in routine care. The Severity of Nail Psoriasis Score (SNAPS; range 0-40: scored one point each for the presence of pitting, onycholysis, hyperkeratosis and/or severe nail disease#in each fingernail) has face validity and has recently demonstrated feasibility, reliability and cross-sectional construct validity against the modified Nail Psoriasis Severity Index (mNAPSI; range 0-130)1.Objectives:We aimed to assess the longitudinal construct validity of SNAPS against the mNAPSI and physician nail VAS (PhNVAS), and to determine the effect size and measurement error of these tools.Methods:Consenting consecutive patients enrolled in the Bath Psoriatic Arthritis (PsA) longitudinal cohort underwent photography of their fingernails at baseline1and 6 months alongside routine clinical assessments. Dorsal images of individual fingernails were acquired using a tripod mounted DSLR camera. An angled mirror positioned distally aided identification of hyperkeratosis. Photograps were scored using SNAPS, mNAPSI and PhNVAS1. Paired statistical analyses were conducted to assess for change in scores from baseline to follow-up. Pairwise correlations between change in SNAPS and change in mNAPSI and PhyNVAS were assessed using Spearman’s rho. Effect sizes and measurement error were calculated.Results:Fifteen patients with a mean (±SD) age of 54.5 (±10.59) were assessed at 6 months. There was a significant reduction in both the mNAPSI and SNAPS scores (p&lt;0.005), with improvements in the most frequently-observed manifestations1i.e. pitting, onycholysis, hyperkeratosis and crumbling (Table 1). No other feature specific to mNAPSI improved over time. There was no significant change using the PhyNVAS. There was a strong correlation between changes in SNAPS and the mNAPSI (Figure 1; rho = 0.838, p&lt;0.001). The correlation between change in SNAPS and PhyNVAS was not statistically significant (rho =0.45, p=0.095) (Figure 1). The change in mNAPSI correlated moderately with the PhNVAS (rho = 0.540, p=0.038). mNAPSI was superior to SNAPS in most parameters of measurement error (Table 2). The mNAPSI and SNAPS had similar effect sizes as measured by the SRM (Table 2).Conclusion:SNAPS demonstrates longitudinal construct validity against the mNAPSI in a small observational cohort of PsA patients as evidenced by a strong correlation between the measures, comparable effect sizes and sensitivity to change over time. Whilst measurement error parameters favored the mNAPSI, SNAPS may be a more feasible measure for studying nail disease in cohort studies.

Geometry accuracy analysis of the three-dimensional model using the close-range photogrammetry method for conservation object of culture (case study: Cow Statue, Faculty Of Livestock, Diponegoro University)

Conservation of cultural objects in the form of maintenance and protection to keep objects from damage and authenticity important. Documentation using a three-dimensional model (3D model) is a cheap, effective and relatively fast solution. The documentation results in the form of a three-dimensional model, which itself must have a good fit of visuals and geometry. The purpose of this study was to analyze the geometry accuracy level and the suitability of the three-dimensional model of physical objects using the close-range photogrammetric method (CRP). This study, using a non-metric camera, namely a DSLR camera to take photos of objects simultaneously and thoroughly according to the CRP concept. The results of the photos are processed based on near-range photogrammetric methods using the VisualSfM technique in point cloud creation followed by Meshlab in making three-dimensional models. The results showed that the shape and color of the model were quite good but still had some rough areas due to a lack of point cloud data. The level of color suitability of the digital model is quite good with several colors in coarse-textured areas that look less suitable for physical objects. The suitability of the geometry of the model through the difference in distance between the test points has an average of 3.524 mm and a standard deviation of 2.989 mm.

THE INFLUENCE OF DRONES ON THE DEVELOPMENT OF ARCHITECHTURAL PHOTOGRAPHY CULTURAL WORKS

&lt;em&gt;Culture of architectural photography is a branch of photography that exposes the aesthetic value of an architectural object of a building&lt;strong&gt;.&lt;/strong&gt; The presence of drone technology in the culture of photography recently brings changes to the results of the photography itself and one of them is in the area of architectural photography. This study aims at verifying the influence of Unmanned Aerial Vehicle technology (Drone) on the artwork of architectural photography. The method used in this research was qualitative method with descriptive technique. Data were collected through library research and field research with observation and interview techniques. The culture using drones offer significant results in architectural photography artworks. The high flexibility of the drone gives results on a very detail architectural artwork. Using a drone also provides a very dazzling point of view that cannot be obtained by using only a DSLR camera. Furthermore by using drone, the artworks of photography are no longer limited by areas that cannot be reached. Therefore by using a drone, the photographer can make architectural photography works with unlimited perspective dimensions. There are some weaknesses of using this drone that the camera and lens are not adjustable and they also cannot be changed.&lt;/em&gt;

Mengoptimalkan Window Ligthing untuk Foto Potret dengan Menggunakan Kamera DSLR 1000D dan 60D

Photography is a visual language that prioritizes the role of light. In photography there are several shooting formats, one of which is portrait or shooting vertically. Portrait photos are photos of a person's face that can reveal the character of the person, therefore the shooting exposure must be precise. In fact, the current portrait photos are not optimal because they do not consider the aspects of light and the correct shooting technique. Portrait photos can easily be done using window lighting techniques. This research was carried out on portrait photos with window lighting techniques produced from two different types of DSLR cameras. In the world of photography especially beginner photographers assume that the higher the level or class of the camera can produce better images. However, in the world of photography the results of good images are not solely produced by professional-class cameras, but by considering the exact exposure when shooting. Through this window lighting technique, researchers hope to find the essence and formula of making portrait photos that are of good quality and can be done by DSLR camera users. A good portrait photo, besides revealing a person's character also has a strong impact power.

Integration the Low Cost Camera Images with the Google Earth Dataset to Create a 3D Model

As known Close range photogrammetry represents one of the most techniques to create precise 3D model. Metric camera, digital camera, and Laser scanning can be exploited for the photogrammetry with variety level of cost that may be high. In this study, the cost level is taken in to consideration to achieve balance between the cost and the obtained accuracy. This study aims to detect potential of low cost tools for creating 3D model in terms of obtained accuracy and details and comparing it with corresponding studies. Smart phone camera is the most available for everyone; this gave the motivation for use in this study. In addition, Google Earth was used to integrate the 3D model produced from all sides including the roof. Then, two different types of the mobile camera were used in addition to the DSLR camera (Digital Single Lens Reflex) for comparison and analysis purposes. Thus, this research gave flexibility in work and low cost resulting from replacement the metric camera with the smart camera and the unmanned aerial vehicle (UAV) with Google Earth data. Mechanism of the work can be summarized in four steps. Firstly, photogrammetry planning to determine suitable baselines from object and location of targets that measured using GPS and Total station devices. Secondly, collect images using close range photogrammetry technique. Thirdly, processing step to create the 3D model and integrated with Google Earth images using the Agi Photoscan software. Finally, Comparative and evaluation stage to derive the accuracy and quality of the model obtained from this study using statistical analysis method. Regarding this Study, University of Baghdad, central library was selected as the case study. The results of this paper show that the low cost 3D model resulted from integrating phone and Google Earth images gave suitable result with mean accuracy level reached to about less than 5 meters compared with DSLR camera result, this may be used for several applications such as culture heritage and architecture documentation.

Modeling the Relationship between Impressions and Image Features of Crinkle Finish of DSLR Camera

Abstract In this article, the authors study the relationships between the principal impressions of crinkle-finished surfaces, which are found on camera exteriors, and the characteristics of test images of crinkle-finished surfaces. They extracted impression words for the surfaces through subjective experiments with humans. The results suggest that the impression is affected by five factors: two physical impression factors and three emotional impression factors. The surface images were obtained using a multi-angle measurement system that was built to collect images under various conditions. The authors used stepwise multiple regression to derive equations to predict the impressions of the surface given the characteristics of its test images. The results of the equations are highly correlated with the subjective scores of the five impression factors. These models will enable designers to design attractive crinkle-finished surfaces and camera exteriors.

An account of a first record of the Common Goldeneye Bucephala clangula Linnaeus, 1758 (Aves: Anseriformes: Anatidae) in Bhutan

PunatsangChhu in Wangduephodrang 27.486°N 89.899°E (1,273m) is one of the largest rivers and an important zone in Bhutan for resident and migrant water birds. It is the expanse where the diverse birds are seen on a stretch between 27.462°N 89.901°E and 27.579°N 89.867°E (Tobgay 2017). Large numbers of winter migratory water birds in Bhutan have been found in this location (Spierenburg 2005). Common Goldeneye Bucephala clangula was first sighted on Saturday, 5th of January, 2019 along PunatsangChhu 27.512657’N 89.887610’E at the elevation of 1142meter above sea level in the morning but couldn’t capture photo and more over mistreated it to be some other common water birds. However, until on 8th of January, 2019, it was a success to have photographed while it was foraging alone at the sand extraction sites at around 12:30 hours in the evening. The duck was observed diving simultaneously under water foraging at the time of sighting. It was then photographed with the help of DSLR camera and kit lens 55–300 mm until it flew away to other side of the river.

Non-invasive methods: The applicability of unmanned aerial vehicle (UAV) technology for recording fossilised footprints

Hominin fossilised trackways are commonly used to reconstruct locomotory behaviour and to characterise track-maker biometrics. They are the most direct representation of hominin locomotion available, yet the fossil sites are susceptible to extreme cases of erosion and weathering, often resulting in the destruction of the fossil beds, as was the case at two prehistoric footprint sites: Formby Point and Happisburgh, UK. Footprints can also be found in easily deformable sediments where the excavator can unintentionally trample and destroy the prints, as occurred at Formby Point, UK. There is the need for non-destructive methods to be identified that can rapidly record the fossil area before further damage can occur to the fossil beds. Because current methods of 3D data capture (laser scanning or photogrammetry) can be invasive (i.e., the excavator is often required to trample the sediment layer during data capture), non-invasive methods need to be explored to circumvent issues in advertently destroying fossil material.In this project, a series of experiments using non-invasive methods tested the applicability of Unmanned Aerial Vehicle (UAV) technology combined with photogrammetry to rapidly and accurately record footprints before further damage to the fossil interface occurred. Various flight paths, UAVs, cameras and capture types (video versus camera stills) were incorporated to test the accuracy in minute depth reconstruction and subsequent 3D mesh creation of small, intricate detail.Shape and size, the consequence of poorly reconstructed depth dimensionality of surfaces, were found to be affected by flight path and by the height of the UAV, indicating that the most optimal method of recording tracks is to use a handheld DSLR camera following a circular or rastered flight path. Despite attempts to utilise UAV technology, inaccurate reconstructions of footprint topography were produced.Although UAV technology produced unreliable reconstructions, UAVs remain a technological solution when sites may be at immediate risk of destruction, as was the case at Happisburgh, UK. The deployment of UAV technology will permit the digital preservation of fossil material which would otherwise be lost.

A camera array system based on DSLR cameras for autostereoscopic prints

In this paper, we present a multi-view camera-array system by using commercial DSLR cameras. In order to produce quality autostereoscopic prints, we initially calibrated the color based on X-Rite color-checker, then automatically adjust the alignment of all images by one black-white checker. In this system, we also utilized an external electronic trigger based on Arduino for synchronizing all cameras to generate bullet-time effect photos. Finally, we converted all photos into multiplexed images then printed them on a lenticular lens panel to be an autostereoscopic photo frame.

Creating high-resolution 360-degree single-line 25K video content for modern conference rooms using film compositing techniques

360-degree image and movie content have been gaining popularity in the last few years all over the media industry. There are two main reasons for this development. On the one hand, it is the immersive character of this media form and, on the other hand, the development of recording and presentation technology has made great progress in terms of resolution and quality. 360-degree panoramas are particularly widespread in VR and AR technology. Despite the high immersive potential, these forms of presentation have the disadvantage that the users are isolated and have no social contact during the presentation. Efforts have therefore been made to project 360-degree content in specially equipped rooms or planetariums to enable a shared experience for the audience. One area of application for 360- degree single-line cylindrical panorama with moving imagery included are modern conference rooms in hotels, which create an immersive environment for their clients to encourage creativity. The aim of this work is to generate high-resolution 25K 360-degree videos for projection in a conference room. The creation of the panoramas uses the single-line cylinder technique and is based on composition technologies that are used in the film industry. Video sequences are partially composed into a still image panorama in order to enable a high native resolution of the final film. A main part of this work is the comparison of different film, video and DSLR cameras, in which different image parameters are examined with respect to the quality of the images. Finally, the advantages, disadvantages and limitations of the procedure are examined.

Experimental study on vertical evacuation capacity of evacuation slide in road shield tunnel

With the massive construction of road shield tunnels, vertical evacuation using slides is increasingly used, for it can save construction cost, improve evacuation efficiency and enhance space utilization. An evacuation experiment in an underwater shield tunnel with 101 participants has been carried out in order to obtain the alighting time of bus passengers, the movement speed, the opening time of the slide cover plate, the evacuation capacity of the slide, the total evacuation time and the behavior characteristics of the participants in the whole evacuation process by using fixed cameras, DSLR cameras and drones. The experiment results showed that the average alighting time for a 46-seat bus full of passengers was 62.3 ± 5.1 s (standard deviation), ranging from 55 s to 72 s. The average evacuation capacity of the evacuation slide was 27 person/min, and the evacuation capacity for males was slightly better than females. The opening time of slide cover plate was greatly affected by slide type and participants. The average movement speed of participants exceeded 4.0 m/s on the driveway with the good lighting conditions, smooth ground and clear evacuation instructions. And the movement speed declined in secure channel. This paper also describes the bottleneck phenomenon in the whole process of evacuation.

Analysis of the Exoplanet HD 189733b to Confirm its Existence

In this study, we examined the orbital periods, photometry, and radial velocity of one exoplanet in the HD star system: 189733 b. We constructed a high caliber exoplanet transit detection tracker that acts as a means to analyze the data constituted of the Raw Science images that we obtained from a DSLR camera. We used the BATMAN Python programming package to convert our data to light curves and a radial-velocity model. The radial velocity data was taken from multiple high precision research studies, which were then converted to a sinusoidal graph portraying the radial velocity with respect to time. Chi-square tests were performed on the data in order to examine the likelihood that observation was due to mere chance. We hypothesized that the creation of a DSLR camera star tracker would produce results that support previously established studies. The results of our studies were statistically significant and supported our hypothesis and previous studies. This study demonstrates the importance of accurately using the radial velocity and photometry data from high-precision research studies.