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Camera System (camera + system)
Selected AbstractsWhy Use a Digital Camera System?DERMATOLOGIC SURGERY, Issue 1 2001Robert A. Yoho MD No abstract is available for this article. [source] Design of an unmanned ground vehicle, bearcat III, theory and practiceJOURNAL OF FIELD ROBOTICS (FORMERLY JOURNAL OF ROBOTIC SYSTEMS), Issue 9 2004Masoud Ghaffari The purpose of this paper is to describe the design and implementation of an unmanned ground vehicle, called the Bearcat III, named after the University of Cincinnati mascot. The Bearcat III is an electric powered, three-wheeled vehicle that was designed for the Intelligent Ground Vehicle Competition and has been tested in the contest for 5 years. The dynamic model, control system, and design of the sensory systems are described. For the autonomous challenge line following, obstacle detection and pothole avoidance are required. Line following is accomplished with a dual camera system and video tracker. Obstacle detection is accomplished with either a rotating ultrasound or laser scanner. Pothole detection is implemented with a video frame grabber. For the navigation challenge waypoint following and obstacle detection are required. The waypoint navigation is implemented with a global positioning system. The Bearcat III has provided an educational test bed for not only the contest requirements but also other studies in developing artificial intelligence algorithms such as adaptive learning, creative control, automatic calibration, and internet-based control. The significance of this effort is in helping engineering and technology students understand the transition from theory to practice. © 2004 Wiley Periodicals, Inc. [source] Autonomous selection and modification of camera configurations using visibility and manipulability measuresJOURNAL OF FIELD ROBOTICS (FORMERLY JOURNAL OF ROBOTIC SYSTEMS), Issue 5 2002Gil W. Chu In this article, we present a camera control method in which the selection of an optimal camera position and the modification of camera configurations are accomplished according to changes in the surroundings. For the autonomous selection and modification of camera configurations during tasks, we consider the camera's visibility and the manipulator's manipulability. The visibility constraint guarantees that the whole of a target object can be "viewed" with no occlusions by the surroundings, and the manipulability constraint guarantees avoidance of the singular position of the manipulator and rapid modification of the camera position. By considering visibility and manipulability constraints simultaneously, we determine the optimal camera position and modify the camera configuration such that visual information for the target object can be obtained continuously during tasks. The results of simulations and experiments show that the active camera system with an eye-in-hand configuration can modify its configuration autonomously according to the motion of the surroundings by applying the proposed camera control method. © 2002 Wiley Periodicals, Inc. [source] Stimulatory action of mitemcinal (GM-611), an acid-resistant non-peptide motilin receptor agonist, on colonic motor activity and defecation: spontaneous and mitemcinal-induced giant migrating contractions during defecation in dogsNEUROGASTROENTEROLOGY & MOTILITY, Issue 10 2009T. Hirabayashi Abstract, The aim of this study was to characterize giant migrating contractions (GMCs) during spontaneous defecation in dogs and to investigate the effect of mitemcinal (an orally active and highly acid-resistant motilin receptor agonist) on colonic motility to assess the possibility of using it for the treatment of colonic motility disorders. To assess colonic motility, strain-gauge force transducers were implanted on the gastrointestinal tract of five dogs, and the behaviour of the dogs was monitored with a noctovision-video camera system. The effect of mitemcinal (0, 3, 10 or 30 mg per dog) and sennoside (300 mg per dog) on colonic motility was assessed 24 h after oral administration. During a 39-day period, the starting point of most of the 140 GMCs was between the transverse colon and the descending colon, but some variation was observed. In the daytime, the GMCs originated from somewhat more proximal positions than at night. Mitemcinal caused an increase in the GMC-index (integration of contractile amplitude and duration) and proximal translocation of the GMC starting point, but did not cause an increase in the number of defecations 12 h after administration. Sennoside, however, caused a significant increase in the number of defecations, an increase in the GMC-index, and prolongation of the duration of GMCs. The GMC starting point in the canine colon varied during spontaneous defecation. Mitemcinal was a potent prokinetic drug to mimic a spontaneous defecation compared with sennoside. Mitemcinal evacuates more intestinal luminal contents during the defecation than does sennoside. [source] Experimentally generated footprints in sand: Analysis and consequences for the interpretation of fossil and forensic footprintsAMERICAN JOURNAL OF PHYSICAL ANTHROPOLOGY, Issue 4 2010K. D'Août Abstract Fossilized footprints contain information about the dynamics of gait, but their interpretation is difficult, as they are the combined result of foot anatomy, gait dynamics, and substrate properties. We explore how footprints are generated in modern humans. Sixteen healthy subjects walked on a solid surface and in a layer of fine-grained sand. In each condition, 3D kinematics of the leg and foot were analyzed for three trials at preferred speed, using an infrared camera system. Additionally, calibrated plantar pressures were recorded. After each trial in sand, the depth of the imprint was measured under specific sites. When walking in sand, subjects showed greater toe clearance during swing and a 7° higher knee yield during stance. Maximal pressure was the most influential factor for footprint depth under the heel. For other foot zones, a combination of factors correlates with imprint depth, with pressure impulse (the pressure-time integral) gaining importance distally, at the metatarsal heads and the hallux. We conclude that footprint topology cannot be related to a single variable, but that different zones of the footprint reflect different aspects of the kinesiology of walking. Therefore, an integrated approach, combining anatomical, kinesiological, and substrate-mechanical insights, is necessary for a correct interpretation. Am J Phys Anthropol, 2010. © 2009 Wiley-Liss, Inc. [source] The Z/I Imaging Digital Camera SystemTHE PHOTOGRAMMETRIC RECORD, Issue 96 2000A. Hinz Market needs for airborne and spaceborne imagery used in photogrammetry and GIS applications are changing. Fundamental changes in sensors, platforms and applications are currently taking place. Most recently, new high resolution spaceborne sensors have become available. Besides classical photogrammetry, new thematic applications will drive the future image market. Savings in cost and time, together with the need for higher and reproducible radiometric resolution or spectral information will push forward the change from analogue to digital imagery. High resolution satellites will compete with airborne film-based photography and digital camera systems. With the availability of a digital airborne camera, it is possible to completely close the digital chain from image acquisition to exploitation and data distribution. The key decision regarding the camera design in this case is whether a linear or area array sensor should be used. In view of the high geometric accuracy requirements in photogrammetry, Z/I Imaging has focused development on a digital camera based on an area sensor. An essential aspect of this decision was not only the aerial camera system, but also the entire photogrammetric process to the finished photographic or mapping product. If this point of view is adopted, it becomes clear that the development of a digital camera involves more than simply exchanging film for silicon. Aspects such as data transfer rates, in-flight data processing and storage, image archiving, georeferencing, colour fusion, calibration and preprocessing have the same influence on the economic assessment of a digital camera system. This paper describes current development activities and application aspects of a digital modular airborne camera system. [source] Determination of the optimal stylet strategy for the C-MAC® videolaryngoscopeANAESTHESIA, Issue 4 2010J. McElwain Summary The C-MAC® videolaryngoscope is a novel intubation device that incorporates a camera system at the end of its blade, thereby facilitating obtaining a view of the glottis without alignment of the oral, pharyngeal and tracheal axes. It retains the traditional Macintosh blade shape and can be used as a direct or indirect laryngoscope. We wished to determine the optimal stylet strategy for use with the C-MAC. Ten anaesthetists were allowed up to three attempts to intubate the trachea in one easy and three progressively more difficult laryngoscopy scenarios in a SimMan® manikin with four tracheal tube stylet strategies: no stylet; stylet; directional stylet (Parker Flex-ItÔ); and hockey-stick stylet. The use of a stylet conferred no advantage in the easy laryngoscopy scenario. In the difficult scenarios, the directional and hockey-stick stylets performed best. In the most difficult scenario, the median (IQR [range]) duration of the successful intubation attempt was lowest with the hockey-stick stylet; 18 s (15,22 [12,43]) s, highest with the unstyletted tracheal tube; 60 s (60,60 [60, 60]) s and styletted tracheal tube 60 s (29,60 [18,60]) s, and intermediate with the directional stylet 21 s (15,60 [8,60]) s. The use of a stylet alone does not confer benefit in the setting of easy laryngoscopy. However, in more difficult laryngoscopy scenarios, the C-MAC videolaryngoscope performs best when used with a stylet that angulates the distal tracheal tube. The hockey-stick stylet configuration performed best in the scenarios tested. [source] A synoptic program for large solar telescopes: Cyclic variation of turbulent magnetic fieldsASTRONOMISCHE NACHRICHTEN, Issue 6 2010L. Kleint Abstract Upcoming large solar telescopes will offer the possibility of unprecedented high resolution observations. However, during periods of non-ideal seeing such measurements are impossible and alternative programs should be considered to best use the available observing time. We present a synoptic program, currently carried out at the Istituto Ricerche Solari Locarno (IRSOL), to monitor turbulent magnetic fields employing the differential Hanle effect in atomic and molecular lines. This program can be easily adapted for the use at large telescopes exploring new science goals, nowadays impossible to achieve with smaller telescopes. The current, interesting scientific results prove that such programs are worthwhile to be continued and expanded in the future. We calculate the approximately achievable spatial resolution at a large telescope like ATST for polarimetric measurements with a noise level below 5 × 10 -5 and a temporal resolution which is sufficient to explore variations on the granular scale. We show that it would be important to optimize the system for maximal photon throughput and to install a high-speed camera system to be able to study turbulent magnetic fields with unprecedented accuracy (© 2010 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source] Dynamic contour tonometry in corneal oedemaACTA OPHTHALMOLOGICA, Issue 2007CA RENNINGS Purpose: Tonometry in corneal oedema is a current problem. In clinical routine intraocular pressure (IOP) may be measured erroneously too low in edematous thickened cornea using Goldmann applanation tonometry. To compare Goldmann applanation tonometry (GAT) and dynamic contour tonometry (DCT, Pascal, Technomed, Germany) in postsurgical corneal oedema. Methods: Fifty patients with cataract were included in a prospective study. IOP was measured by means of GAT and DCT before and one day after cataract surgery. Corneal thickness was determined using a Scheimpflug camera system (Pentacam, Oculus, Germany). Results: After surgery corneal thickness increased significantly (pre-surgery: 548 ,m, post-surgery: 677 ,m, p<0.0001). No significant difference of IOP values measured with DCT compared to GAT was detected before and after cataract surgery (pre-surgery: GAT: 17 ±5 mmHg, DCT: 17 ±6 mmHg; post-surgery: GAT 15 ± 7 mmHg, DCT: 15 ±7 mmHg). IOP measured with DCT and GAT were significantly correlated (pre-surgery: r=0.808, p<0.0001; post-surgery: r=0.767, p<0.0001). The difference between GAT and DCT pre-surgery compared to post-surgery was not significantly different. The IOP difference using GAT or DCT pre-surgery compared to post-surgery was not correlated to the change in corneal thickness. Conclusions: DCT does not give any additional information compared to GAT in patients with corneal oedema. However, a marked difference in IOP values using GAT or DCT is apparent in some subjects. [source] Accurate estimation of the nonlinearity of input/output response for color camerasCOLOR RESEARCH & APPLICATION, Issue 6 2004Vien Cheung Abstract This study investigates techniques for accounting for the nonlinearity of the input/output response of a camera system. A simple power-law form of the nonlinearity was assumed and estimates of the value for the exponent for each of the color channels were made using three different methods. The responses from an Agfa StudioCam camera were linearized and then device characterization was attempted. Characterization errors were up to 10% better using the spectral-sensitivities-based method for estimating the nature of the nonlinearity than using the other two methods. We therefore suggest that the spectral-sensitivities-based method should be preferred for characterization or any other computational process that requires linearization of the camera responses. We expect greater benefits using this method for "low-end" camera systems and/or for cameras where the spectral sensitivities are known or more precisely estimated. We also expect the smoothness of the illumination to influence the error in the estimates of the nonlinearity using the luminance- and mean-reflectance-based methods. © 2004 Wiley Periodicals, Inc. Col Res Appl, 29, 406,412, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/col.20061 [source] Infrared imaging with InAs/GaSb type-II superlatticesPHYSICA STATUS SOLIDI (A) APPLICATIONS AND MATERIALS SCIENCE, Issue 14 2006M. Walther Abstract InAs/GaSb short period superlattices (SLs) with broken gap typ-II band alignment are very well suited for the fabrication of high performance infrared camera systems for the second atmospheric window (3,5 µm). High resolution focal plane arrays for single- and dual-colour applications based on InAs/GaSb SLs have been fabricated. Those camera systems reveal excellent performance data which are comparable and even superior to state of the art thermal imaging systems. (© 2006 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source] The Z/I Imaging Digital Camera SystemTHE PHOTOGRAMMETRIC RECORD, Issue 96 2000A. Hinz Market needs for airborne and spaceborne imagery used in photogrammetry and GIS applications are changing. Fundamental changes in sensors, platforms and applications are currently taking place. Most recently, new high resolution spaceborne sensors have become available. Besides classical photogrammetry, new thematic applications will drive the future image market. Savings in cost and time, together with the need for higher and reproducible radiometric resolution or spectral information will push forward the change from analogue to digital imagery. High resolution satellites will compete with airborne film-based photography and digital camera systems. With the availability of a digital airborne camera, it is possible to completely close the digital chain from image acquisition to exploitation and data distribution. The key decision regarding the camera design in this case is whether a linear or area array sensor should be used. In view of the high geometric accuracy requirements in photogrammetry, Z/I Imaging has focused development on a digital camera based on an area sensor. An essential aspect of this decision was not only the aerial camera system, but also the entire photogrammetric process to the finished photographic or mapping product. If this point of view is adopted, it becomes clear that the development of a digital camera involves more than simply exchanging film for silicon. Aspects such as data transfer rates, in-flight data processing and storage, image archiving, georeferencing, colour fusion, calibration and preprocessing have the same influence on the economic assessment of a digital camera system. This paper describes current development activities and application aspects of a digital modular airborne camera system. [source] GREGOR solar telescope: Design and statusASTRONOMISCHE NACHRICHTEN, Issue 6 2010R. Volkmer Abstract The integration and verification phase of the GREGOR telescope reached an important milestone with the installation of the interim 1 m SolarLite primary mirror. This was the first time that the entire light path had seen sunlight. Since then extensive testing of the telescope and its subsystems has been carried out. The integration and verification phase will culminate with the delivery and installation of the final 1.5 m Zerodur primary mirror in the summer of 2010. Observatory level tests and science verification will commence in the second half of 2010 and in 2011. This phase includes testing of the main optics, adaptive optics, cooling and pointing systems. In addition, assuming the viewpoint of a typical user, various observational modes of the GREGOR Fabry-Pérot Interferometer (GFPI), the Grating Infrared Spectrograph (GRIS), and high-speed camera systems will be tested to evaluate if they match the expectations and science requirements. This ensures that GREGOR will provide high-quality observations with its combination of (multi-conjugate) adaptive optics and advanced post-focus instruments. Routine observations are expected for 2012 (© 2010 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source] Accurate estimation of the nonlinearity of input/output response for color camerasCOLOR RESEARCH & APPLICATION, Issue 6 2004Vien Cheung Abstract This study investigates techniques for accounting for the nonlinearity of the input/output response of a camera system. A simple power-law form of the nonlinearity was assumed and estimates of the value for the exponent for each of the color channels were made using three different methods. The responses from an Agfa StudioCam camera were linearized and then device characterization was attempted. Characterization errors were up to 10% better using the spectral-sensitivities-based method for estimating the nature of the nonlinearity than using the other two methods. We therefore suggest that the spectral-sensitivities-based method should be preferred for characterization or any other computational process that requires linearization of the camera responses. We expect greater benefits using this method for "low-end" camera systems and/or for cameras where the spectral sensitivities are known or more precisely estimated. We also expect the smoothness of the illumination to influence the error in the estimates of the nonlinearity using the luminance- and mean-reflectance-based methods. © 2004 Wiley Periodicals, Inc. Col Res Appl, 29, 406,412, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/col.20061 [source] | |||||||||||||