Compact Digital Camera Research Articles

Influence of Conservation Methods on the sour cherry (Cerasus vulgaris Mill.) fruits quality

Objective: Sour cherry fruits (Cerasus vulgaris Mill.) belong to the Rosaceae family and are designed as a GRAS ingredient based on the FDA data. Animal experiments and clinical practice confirm that there are many positive pharmacological effects mainly related to anthocyanins. Development of standard regulations for this kind of medicinal plant raw materials is actual to introduce sour cherry fruits into official medical practice. In our research, we investigate macroscopic and microscopic properties and determine the content of tanning substances and anthocyanins in sour cherry fruits of various kinds of conservation. Materials and methods: Modern complex of physicochemical methods was used in pharmacognostical research. Microscopic analysis was performed on a LOMO Micmed-6 microscope with 10× eyepieces, 4×, 10×, 40× and 100× objectives, photographies were taken with a Sony Xperia Z3 compact digital camera. The content of total anthocyanins in terms of cyanidin-3-О-glucoside was determined by differential UV-spectrophotometry, total tannins content – by redox titration. Results and discussion: The anomocytic stomatal complex, fruits pulp druses, anthocyanins containing in the epidermis and fruits pulp cells, and vessels are typical signs for the sour cherry fruits anatomy structure. A conservation method has not to effect on visual representation of diagnostic signs. The contents of tanning substances are little; it is from 2.73±0.08% to 4.12±0.13% in terms of tannin. Maximal anthocyanin contents (in terms of cyanidin-3-glucoside and in absolutely dried raw material) were determined in fresh-frozen sour cherry fruits (after defrosting (with juice and without kernel) is 5.40±0.15% or in terms of moisture-containing raw materials (without kernel) – 0.690±0.019%. In the defrosted fruits without juice, the content of anthocyanins is two times lower in terms of completely dried raw material (without kernel), it is 2.77±0.12% or in terms of moisture-containing raw material (without kernel), it is 0.410±0.018%. In the juice released from cherry fruits after defrosting anthocyanin content in terms of cyanidin-3-glucoside is of 0.450±0.007% (g/100ml juice), in dried sour cherry fruits (without kernel) – 4.34±0.17%, which is lower than in fresh-frozen raw materials. It can be explained by the varietal features, as well by the conservation conditions; this matter is to be further studied. Contents of tanning substances in fresh-frozen and dried sour cherry fruits when storage during 4 months is insignificantly reduced, but it is established that contents of anthocyanin in terms of cyanidin-3-glucoside reduces 1.5 times in 4 months, if the raw material is frozen, and it reduces by 10% if the raw material is dried. Conclusion: Diagnostic signs of macroscopic and microscopic structures, contents of tanning substances and anthocyanins in terms of cyanidin 3-glycoside in sour cherry fruits were studied. The content of the main groups of biologically active substances decreases equally during storage of dried and frozen cherry fruits. When defrosting, it is necessary to carefully collect the juice, as it contains the bulk of the anthocyanins. It is promising to study various options for freezing and drying of cherry fruits with kernels in order to reduce the loss of fruits juice to a minimum. In this case, it is important to ensure that the kernels are whole (not destroyed), in order to avoid the ingress of cyanogenic glycosides into the medicinal plant material. The results will be used to develop normative documentation for sour cherry fruits.

Results from the Third QDaedalus Astrogeodetic System Observation Campaign in the Mountainous Terrain of the Surses Region in Switzerland

This study presents the results of an astrogeodetic survey campaign conducted in the mountainous terrain of the Surses region in Switzerland. In our third astrogeodetic campaign using the QDaedalus system, we observed new deflections of the vertical (DoV) using three astrogeodetic systems. These observations were used to validate DoV data derived from the Global Gravity Model GGMplus and the Swiss Geoid model CHGeo2004. Astrogeodetic observations were conducted at 15 benchmarks (BMs) along the astrogeodetic profile over five nights in June 2021 at elevations ranging from 1,185 to 1,800 m and a station spacing of about 1 km. This is the first time two TS60 total station-based QDaedalus systems and one zenith telescope-based COmpact DIgital Astrometric Camera (CODIAC) system were used together for an astrogeodetic observation campaign. The standard deviations (SDs) of the QDaedalus system data for each session were 0.04″–0.22″ and 0.01″–0.20″ for the N–S and E–W components, respectively, while the SDs of the CODIAC system for each session were 0.02″ for both components. These high quality data were compared to DoV data derived from GGMplus and CHGeo2004. The N–S components from GGMplus exhibited large residuals ranging from −2.31″ to 1.75″, while the E–W component residuals are from −0.27″ to 1.80″. The residuals from CHGeo2004 range from −0.60 to 1.21 for the N–S components and −1.01 to 0.32 for the E–W components. These results show that the derived DoV data from CHGeo2004 are closer to the observed DoV and more accurate than the global GGMplus model that does not incorporate local gravity field data. The first and second astrogeodetic observation campaigns were conducted in the coastal terrain of Istanbul, Turkey and in the flat terrain in the Munich region, Germany, respectively. In this study, we provide an overall comparison of these previous results to the GGMplus residuals. Our latest results show that the GGMplus model is of higher quality in the Surses mountainous terrain than in the coastal terrain of Istanbul, while it is of lower quality than in the flat terrain of the Munich region.

Comparative Measurements of Astrogeodetic Deflection of the Vertical by Latvian and Swiss Digital Zenith Cameras

Nowadays, zenith telescope-based digital zenith cameras (DZC), such as the COmpact DIgital Astrometric Camera (CODIAC) and VErtical by STArs (VESTA), are used to determine highly precise astrogeodetic deflections of the vertical (DoVs). The CODIAC and VESTA were developed by Eidgenossische Technische Hochschule (ETH) Zurich and University of Latvia, respectively, and only two CODIACs and four VESTAs were produced. The CODIAC has an established accuracy higher than 0.05″, while the accuracy of VESTA is ~0.1″. These two DZCs, which are the most used DZCs of the last decade, were used effectively over many survey campaigns. In this study, we used both the CODIAC and VESTA to conduct simultaneous observations at the School of Management and Engineering Vaud (HEIG-VD) in Yverdon-les-Bains, Switzerland, over five nights in August 2021. Our DZC measurements with CODIAC and VESTA mark the second time that simultaneous parallel observations were made with two different DZCs. Additionally, the VESTA was never tested against another DZC through comparative simultaneous measurements. These comparative measurements between the VESTA and CODIAC allowed for VESTA precision validation and checking the agreement between the two DZCs. The results of repeated, comparative DoV observations over five nights at HEIG-VD revealed a DoV measurement precision of VESTA around 0.13–0.16″ for 15 min long observation session and 0.10–0.13″ for 50 min long observation session. Mean DoV differences between CODIAC and VESTA at HEIG-VD were 0.08″ and −0.06″ for the North–South and East–West components, respectively.

Digital holographic camera with extended stochastic illumination for non-destructive inspection of silicon optics

In the present work, we propose a compact digital holographic camera (DHC) with extended stochastic illumination for full-field non-destructive inspection of silicon optics fabricated in a computerized numerical control machine. The developed technique overcomes the limitation of digital holography imparted by the finite size of the active area of the recording sensor that can image a specular surface. The original aspect of this research work is to develop a system that enables reconstruction and testing of a specular surface. For this a dual diffuser configuration is incorporated in a compact DHC developed for non-destructive testing (NDT) applications. The generation of a stochastic illumination beam using the diffusers is explained by simulating the propagation of a light beam through a random phase function of the scattering medium. The stochastic optical field produced by the combination of diffusers in the DHC makes the camera suitable for NDT of the specular surface of silicon optics. The effects of the number of diffusers and their relative positions on the imaging area of the specular object are studied for development of an optimized configuration of DHC. Applicability of the proposed scheme is demonstrated through detection of defects in silicon optics using digital holographic interferometry.

Applications of affordance and cognitive ergonomics in virtual design: A digital camera as an illustrative case

Affordance-based design (ABD) plays an important role in identifying interactions, especially effortless ones, between users and artifacts. Cognitive ergonomics extends our understanding of this effortless interaction. This study combines the two design methodologies together in order to reduce cognitive friction in using digital products. The design process of a compact digital camera is selected as a case study that includes the design of the physical shape for a camera and of its user interface. In designing a product shape, a design toolbox was developed that integrated a modified multi-objective genetic algorithm and the ABD, which was named as affordance-based interactive genetic algorithm. Using this toolbox and interactive user feedback, the camera design evolves toward a product that better satisfies the users. User interfaces (UIs) including linear and elliptic layouts were subsequently designed based on cognitive ergonomics. A predictive tool of UI, the Cog Tool, was used to evaluate the performance of skilled users on a given task by correlating the overall task completion time. Finally, this research has the potential to not only effectively address the shortcomings of the design of consumer electronics but also enrich the generation of design solutions during the preliminary design phase of such products.

An Adjustable High-Definition Imaging System for Behavioral Studies of Drosophila Adults.

Drosophila melanogaster is a very powerful model in biological research, but a bad model for photography or videography. This paper describes a simple but effective method to observe and document the behavior or morphology of flies. Flies were placed in a translucent observation chamber c.a. Ø15 x 5mm (no food inside) or Ø15 x 12 mm (with an 8 mm-high piece of food inside). After covering with an ultraviolet (UV)/clear filter with high light transmittance, the chamber was placed under a 5-50x zoom stereo microscope, and mini light-emitting diode (LED) video lights were placed on both sides of the microscope to illuminate the chamber to obtain uniform, soft, bright, and nearly shadow-free light. Then, a compact digital camera with 3-5x optical zoom, which can record 1080 P high-definition or higher resolution video (at a frame rate of ≥30 fps), was connected to the eyepiece of microscope through a bracket, and photographs or videos were taken through the eyepiece. By adjusting the zoom knob of the zoom stereo microscope, it was very easy to track the flies and take panoramic or detailed close-up images as needed, while the camera recorded everything under the microscope. Because the flies can stay at any position in the chamber, they can be observed and recorded from all directions. The photographs or videos taken are of good image quality. This method can be used both for scientific research and teaching.

A systematic review of handheld tools in lieu of colposcopy for cervical neoplasia and female genital schistosomiasis.

BackgroundVisualization of the lesions in the lower genital tract is the mainstay for diagnosis of the four lesions found in female genital schistosomiasis (FGS), but colposcopes are generally not available in low‐resource settings.ObjectiveWe sought to review handheld devices that could potentially be used for FGS diagnosis.Search strategyWe searched Medline and Embase 2015–2019 for handheld devices used in cervical cancer screening and FGS diagnosis.Selection criteriaWe excluded studies that did not compare the device to standard‐of‐care colposcopes or histopathology.Main results and conclusionIn 11 studies, four handheld colposcopes, two smartphones, and one compact digital camera were evaluated. Two handheld colposcopes were found to be potentially adequate for FGS diagnosis, namely Gynocular and Mobile ODT. The smartphones and digital camera did not have sufficient magnification to diagnose grainy sandy patches, one of the FGS lesion types. Customized software should be made to support the diagnosis of both FGS and cervical neoplasia. Real‐time postgraduate training and quality control should be considered in future studies of handheld colposcopes. For patients from schistosomiasis endemic areas, we recommend that handheld devices are used for FGS. Studies are needed to determine which of the two devices is most adequate for FGS diagnosis in schistosomiasis endemic areas.

Stereoscopic three-dimensional (3D) slit-lamp photography using a compact 3D digital camera.

We describe a novel method of stereoscopic 3D slit-lamp photography using a portable compact 3D digital camera. Thirteen eyes of 13 patients underwent slit-lamp photography using a Fujifilm 3D compact digital camera. We modified a universal smartphone microscope adapter to attach the camera to the slit-lamp. Photography was attempted on Zeiss and on HAAG-Streit slit-lamps. Success was defined as capturing a stereogram that consists of two simultaneous pictures, one from each slit-lamp ocular. Stereoscopic 3D slit-lamp photos could be captured in all 13 eyes in which they were attempted on Zeiss slit-lamps. Captured 3D media included external, eyelid, conjunctival, corneal, anterior chamber, lens, vitreous, and optic disc pathologies. Stereoscopic 3D photography could not be obtained using this Fujifilm 3D digital camera on Haag-Streit slit-lamps because of alignment incompatibility between the oculars of the slit-lamp and the camera. Digital stereoscopic 3D slit-lamp photography is feasible using a compact 3D digital camera and compatible slit-lamp design. Images obtained using this technique may be helpful in clinical education.

A COMPARISON OF LOW-COST CAMERAS APPLIED TO FIXED MULTI-IMAGE MONITORING SYSTEMS

Abstract. Photogrammetry is becoming a widely used technique for slope monitoring and rock fall data collection. Its scalability, simplicity of components and low costs for hardware and operations makes its use constantly increasing for both civil and mining applications. Recent on site permanent installation of cameras resulted particularly viable for the monitoring of extended surfaces at very reasonable costs. The current work investigates the performances of a customised Raspberry Pi camera module V2 system and three additional low-cost camera systems including an ELP-USB8MP02G camera module, a compact digital camera (Nikon S3100) and a DSLR (Nikon D3). All system, except the Nikon D3, are available at comparable price. The comparison was conducted by collecting images of rock surfaces, one located in Australia and three located in Italy, from distances between 55 and 110 m. Results are presented in terms of image quality and three dimensional reconstruction error. Thereby, the multi-view reconstructions are compared to a reference model acquired with a terrestrial laser scanner.

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 Simple Strategy for Methylene Blue Determination in Human and Veterinary Dosage Forms by Digital Imaging

A colorimetric method based on digital image processing and an image capture device as a detector has been developed for determining methylene blue (MB) in human and veterinary dosage forms. Operational variables, such as capture devices, angle and modes of capture as well as measuring vessel geometry, were evaluated in order to establish the most suitable conditions to obtain accurate measurements. Three different capture devices including a webcam, a compact digital camera and a smartphone camera were compared. Digital images were analyzed using the open source program ImageJ. Suitable results were achieved when using a 20.7 MP back camera of a smartphone and white-LED lighting conditions. Grayscale values were finally employed as response to determine MB concentration. Satisfactory linearity was achieved in the concentration range from 3.5 × 10–7 to 4.7 × 10–6 M, with the determination coefficient R2 > 0.97 and the limit of detection of 1.7 × 10–7 M. The proposed approach was successfully applied to the detection of MB in two commercially available dosage forms for human and veterinary treatment.

Seeing and communicating: photography and young male adults with Autism Spectrum Disorder

Digital photography is deeply embedded in people’s daily lives, as camera phones and digital compact cameras are widely used in social and cultural settings. People have an increased agency and choice over what they want to photograph, where and when; many people carry their smartphones everywhere and share their images instantly via social media platforms. Within the recent scholarship on everyday photography, however, little attention has been paid to the photographic practices of people with Autism Spectrum Disorder (ASD), one of many marginalized groups whose photography has not been explored. This article addresses this shortfall. Drawing on a qualitative, image-based investigation, the author turns to phenomenology to examine four young male ASD adults’ unique ways of seeing and being-in-the-world as expressed through the use of their camera. Their involvement indicates that ASD people have the potential to have a powerful voice in how society conceives of what autism is and what it means to live with ASD. A case study discussion of key research findings presents examples of the pictures taken in the sphere of participants’ everyday lives, revealing that the camera acts as an extension of experience and perception, a mediator and filter. Photography enables the four male ASD individuals’ being-in-the-world and exposes the social life of this marginalized group. The article offers a significant contribution to the field of visual communication and sensory experience.

Yield prediction by machine learning from UAS-based multi-sensor data fusion in soybean

BackgroundNowadays, automated phenotyping of plants is essential for precise and cost-effective improvement in the efficiency of crop genetics. In recent years, machine learning (ML) techniques have shown great success in the classification and modelling of crop parameters. In this research, we consider the capability of ML to perform grain yield prediction in soybeans by combining data from different optical sensors via RF (Random Forest) and XGBoost (eXtreme Gradient Boosting). During the 2018 growing season, a panel of 382 soybean recombinant inbred lines were evaluated in a yield trial at the Agronomy Center for Research and Education (ACRE) in West Lafayette (Indiana, USA). Images were acquired by the Parrot Sequoia Multispectral Sensor and the S.O.D.A. compact digital camera on board a senseFly eBee UAS (Unnamed Aircraft System) solution at R4 and early R5 growth stages. Next, a standard photogrammetric pipeline was carried out by SfM (Structure from Motion). Multispectral imagery serves to analyse the spectral response of the soybean end-member in 2D. In addition, RGB images were used to reconstruct the study area in 3D, evaluating the physiological growth dynamics per plot via height variations and crop volume estimations. As ground truth, destructive grain yield measurements were taken at the end of the growing season.ResultsAlgorithms and feature extraction techniques were combined to develop a regression model to predict final yield from imagery, achieving an accuracy of over 90.72% by RF and 91.36% by XGBoost.ConclusionsResults provide practical information for the selection of phenotypes for breeding coming from UAS data as a decision support tool, affording constant operational improvement and proactive management for high spatial precision.

Large Scale Topographic Map Comparison Using Unmanned Aerial Vehicle (UAV) Imagers and Real Time Kinematic (RTK)

Large scale topographical mapping is important in geospatial industries in providing high resolution 3D geospatial data sources. The field of aerial photogrammetry also plays an important role in the surveying scope and map production. Nowadays, the use of Unmanned Aerial Vehicle (UAV) platform is a quick way for low altitude aerial data acquisition for mapping. For collecting ground details data at the land-scape level, real time kinematic global positioning system (RTK GPS) is a useful tool for Ground-based topographic mapping. RTK GPS is mobile, collects data quickly at field, and measures elevation within an accuracy of 1 – 5 cm. This work aims to do a comparison of topo-graphic map generated by UAV imagers and by RTK GPS in term of accuracy. The study was conducted using UAV with high resolution non-metric digital compact camera while the ground control point were established using static observation method and ground detail survey using RTK observation method. Vertical accuracy for digital elevation model (DEM) obtained from this study was 8.015 cm at the altitude of 116 m.

Automatic exposure algorithms for digital photography

In this paper we deal with the problem of calculating Automatic Exposure (AE) in digital cameras. The main problem that often occurs when taking pictures is correct exposure setting. Typically, smartphones with built-in cameras, as well as “cheap” compact digital cameras do not offer possibility of manual exposure setting. The reason is that users do not have knowledge how to set the optimal exposure, or just simply do not want to do this. Therefore, it forces that user has to rely on automatic exposure algorithms implemented in the camera. Unfortunately, these algorithms often do not perform well what causes improperly exposed images. In this paper, new algorithms for automatic exposure are proposed with the special focus on minimizing overexposed areas in the images. We have implemented proposed algorithms and conducted experiments for their efficiency, comparing with some modern cameras or smartphones. Experimental verification (enhanced by statistical analysis) shows that proposed algorithms give statistically less overexposed areas than comparative AEs.

Canopy Roughness: A New Phenotypic Trait to Estimate Aboveground Biomass from Unmanned Aerial System.

Cost-effective phenotyping methods are urgently needed to advance crop genetics in order to meet the food, fuel, and fiber demands of the coming decades. Concretely, characterizing plot level traits in fields is of particular interest. Recent developments in high-resolution imaging sensors for UAS (unmanned aerial systems) focused on collecting detailed phenotypic measurements are a potential solution. We introduce canopy roughness as a new plant plot-level trait. We tested its usability with soybean by optical data collected from UAS to estimate biomass. We validate canopy roughness on a panel of 108 soybean [Glycine max (L.) Merr.] recombinant inbred lines in a multienvironment trial during the R2 growth stage. A senseFly eBee UAS platform obtained aerial images with a senseFly S.O.D.A. compact digital camera. Using a structure from motion (SfM) technique, we reconstructed 3D point clouds of the soybean experiment. A novel pipeline for feature extraction was developed to compute canopy roughness from point clouds. We used regression analysis to correlate canopy roughness with field-measured aboveground biomass (AGB) with a leave-one-out cross-validation. Overall, our models achieved a coefficient of determination (R2) greater than 0.5 in all trials. Moreover, we found that canopy roughness has the ability to discern AGB variations among different genotypes. Our test trials demonstrate the potential of canopy roughness as a reliable trait for high-throughput phenotyping to estimate AGB. As such, canopy roughness provides practical information to breeders in order to select phenotypes on the basis of UAS data.

A Method for Dehazing Images Obtained from Low Altitudes during High-Pressure Fronts

Unmanned aerial vehicles (UAVs) equipped with compact digital cameras and multi-spectral sensors are used in remote sensing applications and environmental studies. Recently, due to the reduction of costs of these types of system, the increase in their reliability, and the possibility of image acquisition with very high spatial resolution, low altitudes imaging is used in many qualitative and quantitative analyses in remote sensing. Also, there has been an enormous development in the processing of images obtained with UAV platforms. Until now, research on UAV imaging has focused mainly on aspects of geometric and partially radiometric correction. And consideration of the effects of low atmosphere and haze on images has so far been neglected due to the low operating altitudes of UAVs. However, it proved to be the case that the path of sunlight passing through various layers of the low atmosphere causes refraction and causes incorrect registration of reflection by the imaging sensor. Images obtained from low altitudes may be degraded due to the scattering process caused by fog and weather conditions. These negative atmospheric factors cause a reduction in contrast and colour reproduction in the image, thereby reducing its radiometric quality. This paper presents a method of dehazing images acquired with UAV platforms. As part of the research, a methodology for imagery acquisition from a low altitude was introduced, and methods of atmospheric calibration based on the atmosphere scattering model were presented. Moreover, a modified dehazing model using Wiener’s adaptive filter was presented. The accuracy assessment of the proposed dehazing method was made using qualitative indices such as structural similarity (SSIM), peak signal to noise ratio (PSNR), root mean square error (RMSE), Correlation Coefficient, Universal Image Quality Index (Q index) and Entropy. The experimental results showed that using the proposed dehazing method allowed the removal of the negative impact of haze and improved image quality, based on the PSNR index, even by an average of 34% compared to other similar methods. The obtained results show that our approach allows processing of the images to remove the negative impact of the low atmosphere. Thanks to this technique, it is possible to obtain a dehazing effect on images acquired at high humidity and radiation fog. The results from this study can provide better quality images for remote sensing analysis.

Geometric Evaluation of Mobile-Phone Camera Images for 3D Information

This study aimed to investigate the usability of smartphone camera images in 3D positioning applications with photogrammetric techniques. These investigations were performed in two stages. In the first stage, the cameras of five smartphones and a digital compact camera were calibrated using a calibration reference object, with signalized points having known three-dimensional (3D) coordinates. In the calibration process, the self-calibration bundle adjustment method was used. To evaluate the metric performances, the geometric accuracy tests in the image and object spaces were performed and the test results were compared. In the second stage, a 3D mesh model of a historical cylindrical structure (height = 8 m and diameter = 5 m) was generated using Structure-from-Motion and Multi-View-Stereo (SfM-MVS) approach. The images were captured using the Galaxy S4 smartphone camera, which produced the best result in the geometric accuracy tests for smartphone cameras. The accuracy tests on the generated 3D model were also applied in order to examine 3D object reconstruction capabilities of imaging with this device. The results demonstrated that smartphone cameras can be easily used as image acquisition tools for multiple photogrammetric applications.

HIGH THROUGHPUT PHENOTYPING OF PHYSIOLOGICAL GROWTH DYNAMICS FROM UAS-BASED 3D MODELING IN SOYBEAN

Abstract. Nowadays, an essential tool to improve the efficiency of crop genetics is automated, precise and cost-effective phenotyping of the plants. The aim of this study is to generate a methodology for high throughput phenotyping the physiological growth dynamics of soybeans by UAS-based 3D modelling. During the 2018 growing season, a soybean experiment was performed at the Agronomy Center for Research and Education (ACRE) in West-Lafayette (Indiana, USA). Periodic images were acquired by G9X Canon compact digital camera on board senseFly eBee. The study area is reconstructed in 3D by Image-based modelling. Algorithms and techniques were combined to analyse growth dynamics of the crop via height variations and to quantify biomass. Results provide practical information for the selection of phenotypes for breeding.

Accuracy Analysis of a 3D Model of Excavation, Created from Images Acquired with an Action Camera from Low Altitudes

In the last few years, Unmanned Aerial Vehicles (UAVs) equipped with compact digital cameras, have become a cheap and efficient alternative to classic aerial photogrammetry and close-range photogrammetry. Low-altitude photogrammetry has great potential not only in the development of orthophoto maps but is also increasingly used in surveying and rapid mapping. This paper presents a practical aspect of the application of the custom homemade low-cost UAV, equipped with an action camera, to obtain images from low altitudes and develop a digital elevation model of the excavation. The conducted analyses examine the possibilities of using low-cost UAVs to deliver useful photogrammetric products. The experiments were carried out on a closed excavation in the town of Mince (north-eastern Poland). The flight over the examined area was carried out autonomously. A photogrammetric network was designed, and the reference areas in the mine were measured using the Global Navigation Satellite System-Real Time Kinematic (GNSS-RTK) method to perform accuracy analyses of the excavation 3D model. Representation of the created numerical terrain model was a dense point cloud. The average height difference between the generated dense point cloud and the reference model was within the range of 0.01–0.13 m. The difference between the volume of the excavation measured by the GNSS kinematic method and the volume measured on the basis of a dense point cloud was less than 1%. The obtained results show that the application of the low-cost UAV equipped with an action camera with a wide-angle lens, allows for obtaining high-accuracy images comparable to classic, compact digital cameras.