Digital Camera System Research Articles

Modifying the Silt Lamp by Using a White Laser in Place of the Halogen Light

This paper explores the modification of the slit lamp, a vital ophthalmic instrument, by replacing the traditional halogen light source with a white laser. This modification aims to enhance the diagnostic capabilities and efficiency of the slit lamp. White laser technology offers superior brightness, intensity, and color accuracy, which improves the visibility and differentiation of ocular tissues. Additionally, white lasers are more energy-efficient, provide consistent light output, and require less maintenance. The redesign process includes adjustments to the optical system, incorporating specialized filters and lenses, and ensuring proper thermal management. The integration of a high-resolution digital camera system with white laser illumination further improves image quality and diagnostic precision. The study outlines the benefits, potential challenges, and implementation steps, concluding that the use of white lasers in slit lamps can significantly enhance the effectiveness of ocular diagnostics, benefiting both ophthalmologists and patients.

Retinal Image Dataset of Infants and Retinopathy of Prematurity

Retinopathy of prematurity (ROP) represents a vasoproliferative disease, especially in newborns and infants, which can potentially affect and damage the vision. Despite recent advances in neonatal care and medical guidelines, ROP still remains one of the leading causes of worldwide childhood blindness. The paper presents a unique dataset of 6,004 retinal images of 188 newborns, most of whom are premature infants. The dataset is accompanied by the anonymized patients’ information from the ROP screening acquired at the University Hospital Ostrava, Czech Republic. Three digital retinal imaging camera systems are used in the study: Clarity RetCam 3, Natus RetCam Envision, and Phoenix ICON. The study is enriched by the software tool ReLeSeT which is aimed at automatic retinal lesion segmentation and extraction from retinal images. Consequently, this tool enables computing geometric and intensity features of retinal lesions. Also, we publish a set of pre-processing tools for feature boosting of retinal lesions and retinal blood vessels for building classification and segmentation models in ROP analysis.

Airside Surveillance by Computer Vision in Low-Visibility and Low-Fidelity Environment

Low visibility at airports can significantly impact airside capacity, leading to ground delays and runway/taxiway incursions. Digital tower technology, enabled by live camera feeds, leverages computer vision to enhance airside surveillance and operational efficiency. However, technical challenges in digital camera systems can introduce low-fidelity transmission effects such as blurring, pixelation, or JPEG compression. Additionally, adverse weather conditions like rain and fog can further reduce visibility for tower controllers, whether from digital video or out-of-tower views. This paper proposes a computer vision framework and deep learning algorithms to detect and track aircraft in low-visibility (due to bad weather) and low-fidelity (due to technical issues) environments to enhance visibility using digital video input. The framework employs a convolutional neural network for aircraft detection and Kalman filters for tracking, especially in low-visibility conditions. Performance enhancements come from pre- and postprocessing algorithms like object filtering, corrupted image detection, and image enhancement. It proves effective on an airport video dataset from Houston Airport, enhancing visibility under adverse weather conditions.

Drought shortens subtropical understory growing season by advancing leaf senescence.

Subtropical forests, recognized for their intricate vertical canopy stratification, exhibit high resistance to extreme drought. However, the response of leaf phenology to drought in the species-rich understory remains poorly understood. In this study, we constructed a digital camera system, amassing over 360,000 images through a 70% throughfall exclusion experiment, to explore the drought response of understory leaf phenology. The results revealed a significant advancement in understory leaf senescence phenology under drought, with 11.75 and 15.76 days for the start and end of the leaf-falling event, respectively. Pre-season temperature primarily regulated leaf development phenology, whereas soil water dominated the variability in leaf senescence phenology. Under drought conditions, temperature sensitivities for the end of leaf emergence decreased from -13.72 to -11.06 days °C-1, with insignificance observed for the start of leaf emergence. Consequently, drought treatment shortened both the length of the growing season (15.69 days) and the peak growth season (9.80 days) for understory plants. Moreover, this study identified diverse responses among intraspecies and interspecies to drought, particularly during the leaf development phase. These findings underscore the pivotal role of water availability in shaping understory phenology patterns, especially in subtropical forests.

Initial institutional experience using a robotic arm-enabled 4K 3D exoscope in neurosurgical operations.

The extracorporeal telescope (exoscope) presents a novel digital camera system as a versatile alternative to traditional optical microscopy for microsurgery and minimally invasive neurosurgical operations. Recent innovations in exoscope technology offer 4K-definition multiscreen outputs, pneumatic robot arms, 3-dimensional depth perception, and greater illumination, focus, and magnification powers for enhanced intraoperative visualization. The authors present their initial institutional experience using a robotic arm-enabled 4K 3D exoscope in a variety of cranial and spinal neurosurgical operations, namely Chiari decompression, microvascular decompression for trigeminal neuralgia, anterior cervical discectomy, and lumbar decompressions. The video can be found here: https://stream.cadmore.media/r10.3171/2023.10.FOCVID23150.

First Record, Distribution and Occurrence of A Protistan Entomopathogen, Adelina mesnili Perez (Coccidia: Adeleidae) in the Indian Meal Moth, Plodia interpunctella (Hübner) (Lepidoptera: Pyralidae) Populations in Türkiye.

Plodia interpunctella (Hübner) (Lepidoptera: Pyralidae) originating from South America is one of the important insect pests that damages storage products and is found on every continent. There is a new interest in using enthomopathogens for microbial control of P. interpunctella as well as other stored product pests. Coccidia as a group of protistan entomopathogens are host specific and their pathogenic effects on the hosts are more pronounced. Although this pathogenic effect results in increased host mortality or higher susceptibility to insecticides, the suppressive potential of coccidia in natural populations has not been adequately studied. In this study, characterization, distribution and occurrence of a coccidian entomopathogen was aim to show its natural suppressing potential in P. interpunctella populations. During the three years (from 2019 to 2021), a total of 3.432 P. interpunctella samples (2.047 dead and 413 living larvae, 932 adults and 40 pupae) were collected from fourteen populations. After macroscopic examination, suspected samples were dissected in Ringer's solution and then prepared wet smears including host fat body were examined for presence of coccidian pathogens under a light microscope at a magnification of 400-1000X. The oocysts of the coccidian were measured and photographed using a microscope with a digital camera and soft imaging system. The pathogen was observed in the fat bodies of the larvae, pupae and adults. Oocysts measured as 29.52±3.32 (25.27- 35.08) μm in diameter and they include 8 sporocysts. Sporocysts measured as 9.11±0.61 (8.90-9.85) μm. Forty-five of 3.432 P. interpunctella larvae, pupae and adults were found to be infected. Coccidian infections have also reached to the levels that can be considered high in some populations, as significant as 29.2%. The infection was observed in the three (21.4%) of the examined fourteen populations. The coccidian entomopathogen presented in this study is the first Adeleid coccidian record from P. interpunctella populations in Türkiye. The detection of Adelina mesnili Perez (Coccidia: Adeleidae) in at least three populations and the infection rate reaching 29.2 percent, confirms that this pathogen has a considerable effect P. interpunctella populations that cannot be underestimated. Our results confirm that the coccidian pathogen is very effective in the larval stage.

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.

Comparison of a high-definition three-dimensional digital camera system with a conventional state-of-the-art operation microscope for microsurgical anastomoses

Since its clinical implementation, microvascular surgery has depended on the continuous improvement of magnification tools. One of the more recent developments is a high-definition three-dimensional (3D) digital system (exoscope), which provides an alternative to the state-of-the-art operating microscopes. This study aimed to evaluate the advantages and disadvantages of this technology and compare it with its predecessor. The study included 14 surgeons with varying levels of experience, none of which had used a 3D optical system previously. Six of these surgeons performed five arterial and five venous anastomoses in the chicken thigh model with both the VITOM 3D exoscope-guided system and the Pentero operating microscope. These anastomoses were then evaluated for their quality and anastomosis time. The participants and the other eight surgeons, who had used the digital 3D camera system for microsurgical training exercises and vascular sutures, answered a questionnaire. The anastomosis time and number of complications were lower with the conventional microscope. Participants rated the image quality with the conventional microscope as higher, whereas the field of view and ergonomics were favorable in the digital 3D camera system. Exoscopes are optics suitable for performing simple microvascular procedures and are superior to classical microscopes ergonomically. Thus far, they are inferior to classical microscopes in terms of image quality and 3D imaging.

A combination of Light Detection and Ranging with Digital Panoramic Borehole Camera System in fracture mapping to characterize discrete fracture networks

A combination of Light Detection and Ranging with Digital Panoramic Borehole Camera System in fracture mapping to characterize discrete fracture networks

Use of unmanned ground vehicle systems in urbanized zones: A study of vector Mosquito surveillance in Kaohsiung.

Dengue fever is a vector-borne disease that has become a serious global public health problem over the past decade. An essential aspect of controlling and preventing mosquito-borne diseases is reduction of mosquito density. Through the process of urbanization, sewers (ditches) have become easy breeding sources of vector mosquitoes. In this study, we, for the first time, used unmanned ground vehicle systems (UGVs) to enter ditches in urban areas to observe vector mosquito ecology. We found traces of vector mosquitoes in ~20.7% of inspected ditches, suggesting that these constitute viable breeding sources of vector mosquitoes in urban areas. We also analyzed the average gravitrap catch of five administrative districts in Kaohsiung city from May to August 2018. The gravitrap indices of Nanzi and Fengshan districts were above the expected average (3.26), indicating that the vector mosquitoes density in these areas is high. Using the UGVs to detect positive ditches within the five districts followed by insecticide application generally yielded good control results. Further improving the high-resolution digital camera and spraying system of the UGVs may be able to effectively and instantly monitor vector mosquitoes and implement spraying controls. This approach may be suitable to solve the complex and difficult task of detecting mosquito breeding sources in urban ditches.

Consistency Discrimination and Experimental Study of Rock Discontinuities Based on Borehole Optical Images

The structural plane is a geological interface of a particular scale, and how to determine the extension of the structural plane in space is an essential issue in the study of rock structure. This paper analyses the structural plane information of multiple boreholes collected by the digital panoramic borehole camera system to determine the structural plane consistency. The discriminative conditions of structural plane consistency in multiple boreholes are deduced through mathematical analysis methods such as spatial geometry and vector. The structural planes that may be connected are quickly screened out. The consistency is further judged by combining the relevant characteristics of the structural planes, thus forming a complete method based on digital borehole images. The method has been validated by a series of indoor tests. Structural planes with specific parameters were presented in the test blocks in these tests, and several boreholes were drilled. The experimental results show that (1) the structural plane consistency discrimination method can be applied to both flat structural planes and structural planes with certain undulation angles and roughness; (2) the tilt of the borehole does not affect the structural plane consistency using the borehole camera, and the structural plane consistency can be judged by this method in any two boreholes in space; and (3) the analysis method proposed in this paper can quickly complete the structural plane consistency discrimination, and is also suitable for the consistency discrimination and screening of a large number of structural planes in deep boreholes. Finally, the method based on the optical borehole images is successfully applied in the slope survey of the Xichang iron ore mine.

The Surgeon Ergonomic Impact of a Tubular-Based Digital Camera to Perform a Seated Posterior Cervical Foraminotomy

Posterior cervical decompression is a common spine procedure that can be performed with the patient in prone or sitting position. The sitting position provides the potential benefits of more facile retraction of surrounding soft tissues, increased operative field and fluoroscopic visualization, and decreased epidural bleeding. However, the surgeon's ergonomics of this positioning can be quite challenging when using the standard operative microscope to perform the procedure and may cause musculoskeletal harm to the surgeon. A sterile digital camera was brought into the field to perform a sitting foraminotomy completed through the tube retractor at both C6-7 and C7-T1 levels. For half of the procedure, a typical neurosurgical operative microscope was brought into the field to evaluate surgeon ergonomics using baseline Rapid Entire Body Assessment (REBA) scores for 2 surgeons of differing stature. The digital camera was inserted onto the tubular retractor, and REBA scores were calculated. With a microscope, the surgeon with taller stature scored a 5 on the initial REBA scale, and the surgeon with shorter stature scored a 6, placing both in the medium-risk category. Once the tubular-based camera was placed, repeated REBA score of both surgeons was 3, placing them in the low-risk category. Using a tubular-based digital camera system, the ergonomics of the surgery are substantially improved. The surgeon can stand closer to the operative field and look directly at a front-facing screen, allowing increased relaxation of the upper extremity and cervical musculature; improving overall ergonomic function.

Visualization of dose distribution and basic study of dose estimation using plastic scintillator and digital camera

Radiation can be visualized using a scintillator and a digital camera. If the amount of light emitted by the scintillator increases with dose, the dose estimation can be obtained from the amount of light emitted. In this study, the basic performance of the scintillator and digital camera system was evaluated by measuring computed tomography dose index (CTDI). A circular plastic scintillator plate was sandwiched between polymethyl methacrylate (PMMA) phantoms, and x-rays were irradiated to them while rotating the x-ray tube to confirm changes in light emission. In addition, CTDI was estimated from the amount of light emitted by the scintillator during the helical scan and compared with the value measured from dosimeter. The scintillator emitted light while changing its distribution according to the movement of the x-ray tube. The measured CTDIvol was 33.20 mGy, the CTDIvol estimated from the scintillation light was approximately 46 mGy, which was 40% larger. In particular, when the scintillator was directly irradiated, the dose was overestimated compared with the value measured from the dosimeter. This overestimation can be because of the reproducibility of the position and the difference between the sensitivity of the scintillator to detect light emission and the sensitivity of the dosimeter, and the non-uniformity of position sensitivity due to the wide-angle lens.

ISRAELI NATIONAL AERIAL DATA CAPTURING STANDARD FOR GENERATION OF DIGITAL GEOSPATIAL PRODUCTS AT NATIONAL SCALE

Abstract. Digital camera systems are a key component in the production of reliable, geometrically accurate, high-resolution geospatial products in a national scale. These systems have replaced film imaging in photogrammetric data capturing. Today, we are witnessing a proliferation of imaging sensors, collecting images in different ground resolutions, spectral bands, swath sizes, radiometric characteristics and accuracies being carried on varied mobile platforms. In addition, these imaging sensors combined with navigational tools (such as GPS and IMU), active sensors such as laser scanning and powerful processing tools, to obtain high quality geospatial products. The quality of these geospatial products based on the utilization of calibrated, high-quality digital camera systems.The new Survey of Israel (SOI) regulations specify the quality requirements for each geospatial product including maps at different scales and for different purposes, elevation models, ortho imagery etc. In addition, the regulations require that digital camera systems utilized for mapping purposes should be certified, using a rigorous mapping systems certification and validation process, which are specified in the SOI Director General Instructions (DGI).In 2019 the SOI has updated the camera certification and validation procedure and published a new national aerial capturing standard for digital geospatial products as a basis for the public bid in three main fields:Aerial data capturing including ground control points (GCP) measurements and aerial triangulation.Ortho imagery in several ground resolution distance (GSD) and several projections.Digital Elevation models including: points clouds, Digital Surface Model (DSM) and Digital Terrain Model (DTM). This article provides the details of the Israeli Directive for camera certification and Standard for digital geospatial products including the main technical requirements of the public bid that was carried out.

Experimental Investigation on Slip Conditions during Thread Rolling with Flat Dies

Rolling operations with flat dies allow the highly efficient production of cylindrical parts in large quantities. [1] Latest trends towards shorter lifecycle times and increasing product complexity [2] strengthen the need for an efficient design process of flat die rolling operations. Finite element modelling plays a major role in establishing an efficient design process. Precise modelling of the friction conditions during rolling operations with flat dies is still posing a challenge today. [3] The present work aims to experimentally identifying the limits of rolling of an axisymmetric part, using flat dies. By gradually increasing the stroke rate, the process limits caused by excessive slippage are determined for six different tribological systems. The workpiece rotation and tool movement is measured optically by using a digital camera system. Large differences in slippage are observed, depending on the tribological system. While systems with polymer based lubricants show excessive slippage at low stroke rates, systems using oil or no lubricant bear higher stroke rates before process limits are reached. Furthermore the optical measurements reveal that slip may also occur without complete process failure leading to the assumption that the process limit of excessive slippage in rolling operations is rather fluent than binary. Based on this experimental data, future investigations will focus on methods to predict these process limits through FEM using advanced friction modelling and tribometer tests.

Application of Wireless Sensor Networks to Prevent the Spread of Forest Fires

The objective of this article is to identify current trends and prospects for the use of technical facilities and installations to prevent the spread of wildfires by analyzing the literature. The analysis of the literature has allowed an analysis of different ground-based wildfire detection and monitoring systems: optical sensors and digital camera systems, and wireless sensor network systems. The author concludes that the wireless sensor network can be seen as a partial solution when used in combination with other technologies. Keywords—observation towers, optical systems, optical sensors, digital cameras, wireless sensor network.

Результаты сравнения астрономо-геодезического и навигационно-геодезического методов определения составляющих уклонения отвесной линии

The authors present the results of comparing the components of deflection of vertical obtained through astronomical-geodetic and navigational-geodetic methods. The first one is based on comparing astronomical and geodetic coordinates of a location. This method has recently been widely implemented in a digital zenith camera systems using a small-sized digital telescope with an astronomical camera based on CCD or CMOS technologies, a high-precision inclinometer and satellite navigation system receiver. In this case, the combination of a telescope, an astronomical camera and an inclinometer enables determining the local direction of the plumb line, expressed by astronomical coordinates, from observations of stars at the zenith and using high-precision star catalogs. The navigational-geodetic method is based on comparing the results of the normal heights’ increments, defined through geometric leveling, and geodetic heights, computed with the relative method of satellite coordinate determinations. For each method, random and systematic components of the error and its confidence bounds were calculated; the absolute values of the deflection of vertical components at two geographically separated points were compared.

62 Comparative Analysis of Digital Camera Systems for the Documentation of Anogenital Injuries Following Sexual Assault

Photo-documentation is a standard of care and essential skill for forensic clinicians responding to patients affected by violence and trauma. Colposcope images have been shown to have poor accuracy as well as limited interobserver agreement for the classification and location of anogenital injuries following sexual assault. This retrospective study compares the frequency and type of anogenital injuries detected by colposcope digital imaging compared to those injuries detected using a high-resolution camera system.

Application of 3D Image Technology in Motor and Sensory Nerve Classification

Objective. To explore the application of 3D image technology in motor and sensory nerve classification. Methods. A total of 200 sections of the 5cm-long popliteal fossa peroneal nerve from adult volunteers were cut and frozen. The slices were 10 m thick, and the interval between the slices was 0.25 mm. Acetylcholinesterase histochemical staining was used to observe the changes of nerve bundles under the microscope. The stained sections were transformed into digital images by the digital camera system, and the images were stitched to obtain a two-dimensional panoramic image 100 times magnified. The properties of the functional bundles were manually judged. Using Amira 3.1 three‐dimensional reconstruction software to realize the three-dimensional reconstruction and visualization of nerve can not only accurately perceive the complex three-dimensional surface structure of nerve, but also arbitrarily display, rotate, scale, and segment the three-dimensional structure inside nerve, and carry out three-dimensional measurement in time. It has made preliminary achievements in brachial plexus, lumbosacral plexus, neural stem functional bundle (group), and intramuscular nerve routing and distribution, including the regeneration process of sensory nerve and three-dimensional reconstruction and visualization of composite tissue containing sensory nerve. Conclusion. Based on histology and computer technology, the functional band of short peroneal nerve can be reconstructed in 3D, which provides a feasible basis for the three-dimensional reconstruction of the functional band of the long peripheral nerve.

Benchmarking acquisition parameters for digital aerial photogrammetric data for forest inventory applications: Impacts of image overlap and resolution

Research has demonstrated the utility of digital aerial photogrammetry (DAP) for area-based predictions of forest inventory attributes. To date, studies have used DAP data acquired with a range of spatial resolutions and image overlaps. The systematic benchmarking of DAP acquisition parameters remains an outstanding research and operational gap for forest applications. While the impact of along-track overlap on point cloud metrics and area-based attribute estimates can be readily simulated, the impact of image resolution or across-track overlap requires purpose-acquired data. Moreover, although increases in along-track overlap are enabled by digital camera systems, costs for increasing across-track overlap can be substantial and may negate the cost-effectiveness of DAP for forest inventory. Hence, determining the impacts of varying acquisition parameters is of practical value for inventory programs. Researchers and practitioners have often assumed that more overlap will result in better DAP data, and that minimal overlaps often associated with historic airborne image campaigns are inadequate to support DAP processing. In our study, we found no marked difference among 15 and 20 cm spatial resolutions and overlap scenarios unless across-track overlap was reduced to 40%. Mean differences between DAP metrics and the ALS reference generally increased with decreasing overlap, and mean differences were larger for lower height percentiles (p10). Estimates of canopy height using the p90 metric varied by a root mean squared difference (RMSD) of approximately 5% between 15 cm and 20 cm datasets when along-track overlap was greater than 40%. Lower height percentiles were more strongly impacted by overlaps and resolution. Cover metrics varied by 2% RMSD across all overlap scenarios and resolutions. Comparisons between forest types (conifer, deciduous, mixed), terrain slope and aspect, and ALS-derived canopy cover were conducted to determine whether significant mean differences existed between DAP and the ALS reference. Although some significant differences were found by forest type and terrain variables, significant differences were most commonly associated with canopy cover. Based on the results reported herein, along and across-track overlaps ≥ 60% result in DAP metrics that were more similar to ALS. Increasing across-track overlap from 60% to 80% did not consistently improve the level of agreement between DAP metrics and ALS reference metrics. Conversely, DAP metrics generated using across-track overlaps <60% resulted in metrics with greater differences from the ALS reference, and a greater range of variability in DAP metric values. Image acquisitions for forest inventory must consider a broad range of factors and herein we have quantified that increasing along- or across-track overlap beyond 60% does not improve agreement with ALS area-based point cloud metrics commonly used to model forest inventory attributes. Likewise, overlap that is <60% does result in greater differences with ALS reference. Other applications beyond forest inventory may have different overlap requirements.