A state observer for using a slow camera as a sensor for fast control applications

NASA Astrophysics Data System (ADS)

Gahleitner, Reinhard; Schagerl, Martin

2013-03-01

This contribution concerns about a problem that often arises in vision based control, when a camera is used as a sensor for fast control applications, or more precisely, when the sample rate of the control loop is higher than the frame rate of the camera. In control applications for mechanical axes, e.g. in robotics or automated production, a camera and some image processing can be used as a sensor to detect positions or angles. The sample time in these applications is typically in the range of a few milliseconds or less and this demands the use of a camera with a high frame rate up to 1000 fps. The presented solution is a special state observer that can work with a slower and therefore cheaper camera to estimate the state variables at the higher sample rate of the control loop. To simplify the image processing for the determination of positions or angles and make it more robust, some LED markers are applied to the plant. Simulation and experimental results show that the concept can be used even if the plant is unstable like the inverted pendulum.

R&D 100, 2016: Ultrafast X-ray Imager

ScienceCinema

Porter, John; Claus, Liam; Sanchez, Marcos; Robertson, Gideon; Riley, Nathan; Rochau, Greg

2018-06-13

The Ultrafast X-ray Imager is a solid-state camera capable of capturing a sequence of images with user-selectable exposure times as short as 2 billionths of a second. Using 3D semiconductor integration techniques to form a hybrid chip, this camera was developed to enable scientists to study the heating and compression of fusion targets in the quest to harness the energy process that powers the stars.

R&D 100, 2016: Ultrafast X-ray Imager

DOE Office of Scientific and Technical Information (OSTI.GOV)

Porter, John; Claus, Liam; Sanchez, Marcos

The Ultrafast X-ray Imager is a solid-state camera capable of capturing a sequence of images with user-selectable exposure times as short as 2 billionths of a second. Using 3D semiconductor integration techniques to form a hybrid chip, this camera was developed to enable scientists to study the heating and compression of fusion targets in the quest to harness the energy process that powers the stars.

Camera-on-a-Chip

NASA Technical Reports Server (NTRS)

1999-01-01

Jet Propulsion Laboratory's research on a second generation, solid-state image sensor technology has resulted in the Complementary Metal- Oxide Semiconductor Active Pixel Sensor (CMOS), establishing an alternative to the Charged Coupled Device (CCD). Photobit Corporation, the leading supplier of CMOS image sensors, has commercialized two products of their own based on this technology: the PB-100 and PB-300. These devices are cameras on a chip, combining all camera functions. CMOS "active-pixel" digital image sensors offer several advantages over CCDs, a technology used in video and still-camera applications for 30 years. The CMOS sensors draw less energy, they use the same manufacturing platform as most microprocessors and memory chips, and they allow on-chip programming of frame size, exposure, and other parameters.

Brute Force Matching Between Camera Shots and Synthetic Images from Point Clouds

NASA Astrophysics Data System (ADS)

Boerner, R.; Kröhnert, M.

2016-06-01

3D point clouds, acquired by state-of-the-art terrestrial laser scanning techniques (TLS), provide spatial information about accuracies up to several millimetres. Unfortunately, common TLS data has no spectral information about the covered scene. However, the matching of TLS data with images is important for monoplotting purposes and point cloud colouration. Well-established methods solve this issue by matching of close range images and point cloud data by fitting optical camera systems on top of laser scanners or rather using ground control points. The approach addressed in this paper aims for the matching of 2D image and 3D point cloud data from a freely moving camera within an environment covered by a large 3D point cloud, e.g. a 3D city model. The key advantage of the free movement affects augmented reality applications or real time measurements. Therefore, a so-called real image, captured by a smartphone camera, has to be matched with a so-called synthetic image which consists of reverse projected 3D point cloud data to a synthetic projection centre whose exterior orientation parameters match the parameters of the image, assuming an ideal distortion free camera.

State of the art in video system performance

NASA Technical Reports Server (NTRS)

Lewis, Michael J.

1990-01-01

The closed circuit television (CCTV) system that is onboard the Space Shuttle has the following capabilities: camera, video signal switching and routing unit (VSU); and Space Shuttle video tape recorder. However, this system is inadequate for use with many experiments that require video imaging. In order to assess the state-of-the-art in video technology and data storage systems, a survey was conducted of the High Resolution, High Frame Rate Video Technology (HHVT) products. The performance of the state-of-the-art solid state cameras and image sensors, video recording systems, data transmission devices, and data storage systems versus users' requirements are shown graphically.

Establishing imaging sensor specifications for digital still cameras

NASA Astrophysics Data System (ADS)

Kriss, Michael A.

2007-02-01

Digital Still Cameras, DSCs, have now displaced conventional still cameras in most markets. The heart of a DSC is thought to be the imaging sensor, be it Full Frame CCD, and Interline CCD, a CMOS sensor or the newer Foveon buried photodiode sensors. There is a strong tendency by consumers to consider only the number of mega-pixels in a camera and not to consider the overall performance of the imaging system, including sharpness, artifact control, noise, color reproduction, exposure latitude and dynamic range. This paper will provide a systematic method to characterize the physical requirements of an imaging sensor and supporting system components based on the desired usage. The analysis is based on two software programs that determine the "sharpness", potential for artifacts, sensor "photographic speed", dynamic range and exposure latitude based on the physical nature of the imaging optics, sensor characteristics (including size of pixels, sensor architecture, noise characteristics, surface states that cause dark current, quantum efficiency, effective MTF, and the intrinsic full well capacity in terms of electrons per square centimeter). Examples will be given for consumer, pro-consumer, and professional camera systems. Where possible, these results will be compared to imaging system currently on the market.

Person re-identification over camera networks using multi-task distance metric learning.

PubMed

Ma, Lianyang; Yang, Xiaokang; Tao, Dacheng

2014-08-01

Person reidentification in a camera network is a valuable yet challenging problem to solve. Existing methods learn a common Mahalanobis distance metric by using the data collected from different cameras and then exploit the learned metric for identifying people in the images. However, the cameras in a camera network have different settings and the recorded images are seriously affected by variability in illumination conditions, camera viewing angles, and background clutter. Using a common metric to conduct person reidentification tasks on different camera pairs overlooks the differences in camera settings; however, it is very time-consuming to label people manually in images from surveillance videos. For example, in most existing person reidentification data sets, only one image of a person is collected from each of only two cameras; therefore, directly learning a unique Mahalanobis distance metric for each camera pair is susceptible to over-fitting by using insufficiently labeled data. In this paper, we reformulate person reidentification in a camera network as a multitask distance metric learning problem. The proposed method designs multiple Mahalanobis distance metrics to cope with the complicated conditions that exist in typical camera networks. We address the fact that these Mahalanobis distance metrics are different but related, and learned by adding joint regularization to alleviate over-fitting. Furthermore, by extending, we present a novel multitask maximally collapsing metric learning (MtMCML) model for person reidentification in a camera network. Experimental results demonstrate that formulating person reidentification over camera networks as multitask distance metric learning problem can improve performance, and our proposed MtMCML works substantially better than other current state-of-the-art person reidentification methods.

Environmental performance evaluation of an advanced-design solid-state television camera

NASA Technical Reports Server (NTRS)

1979-01-01

The development of an advanced-design black-and-white solid-state television camera which can survive exposure to space environmental conditions was undertaken. A 380 x 488 element buried-channel CCD is utilized as the image sensor to ensure compatibility with 525-line transmission and display equipment. Specific camera design approaches selected for study and analysis included: (1) component and circuit sensitivity to temperature; (2) circuit board thermal and mechanical design; and (3) CCD temperature control. Preferred approaches were determined and integrated into the final design for two deliverable solid-state TV cameras. One of these cameras was subjected to environmental tests to determine stress limits for exposure to vibration, shock, acceleration, and temperature-vacuum conditions. These tests indicate performance at the design goal limits can be achieved for most of the specified conditions.

SOAR Optical Imager (SOI) | SOAR

Science.gov Websites

SPARTAN Near-IR Camera Ohio State Infrared Imager/Spectrograph (OSIRIS) - NO LONGER AVAILABLE SOAR ?: ADS link to SOI instrument SPIE paper Last update: C. Briceño, Aug 23, 2017 SOAR Optical Imager

Imaging characteristics of photogrammetric camera systems

USGS Publications Warehouse

Welch, R.; Halliday, J.

1973-01-01

In view of the current interest in high-altitude and space photographic systems for photogrammetric mapping, the United States Geological Survey (U.S.G.S.) undertook a comprehensive research project designed to explore the practical aspects of applying the latest image quality evaluation techniques to the analysis of such systems. The project had two direct objectives: (1) to evaluate the imaging characteristics of current U.S.G.S. photogrammetric camera systems; and (2) to develop methodologies for predicting the imaging capabilities of photogrammetric camera systems, comparing conventional systems with new or different types of systems, and analyzing the image quality of photographs. Image quality was judged in terms of a number of evaluation factors including response functions, resolving power, and the detectability and measurability of small detail. The limiting capabilities of the U.S.G.S. 6-inch and 12-inch focal length camera systems were established by analyzing laboratory and aerial photographs in terms of these evaluation factors. In the process, the contributing effects of relevant parameters such as lens aberrations, lens aperture, shutter function, image motion, film type, and target contrast procedures for analyzing image quality and predicting and comparing performance capabilities. ?? 1973.

Extrinsic Calibration of Camera Networks Based on Pedestrians

PubMed Central

Guan, Junzhi; Deboeverie, Francis; Slembrouck, Maarten; Van Haerenborgh, Dirk; Van Cauwelaert, Dimitri; Veelaert, Peter; Philips, Wilfried

2016-01-01

In this paper, we propose a novel extrinsic calibration method for camera networks by analyzing tracks of pedestrians. First of all, we extract the center lines of walking persons by detecting their heads and feet in the camera images. We propose an easy and accurate method to estimate the 3D positions of the head and feet w.r.t. a local camera coordinate system from these center lines. We also propose a RANSAC-based orthogonal Procrustes approach to compute relative extrinsic parameters connecting the coordinate systems of cameras in a pairwise fashion. Finally, we refine the extrinsic calibration matrices using a method that minimizes the reprojection error. While existing state-of-the-art calibration methods explore epipolar geometry and use image positions directly, the proposed method first computes 3D positions per camera and then fuses the data. This results in simpler computations and a more flexible and accurate calibration method. Another advantage of our method is that it can also handle the case of persons walking along straight lines, which cannot be handled by most of the existing state-of-the-art calibration methods since all head and feet positions are co-planar. This situation often happens in real life. PMID:27171080

Imaging bolometer

DOEpatents

Wurden, G.A.

1999-01-19

Radiation-hard, steady-state imaging bolometer is disclosed. A bolometer employing infrared (IR) imaging of a segmented-matrix absorber of plasma radiation in a cooled-pinhole camera geometry is described. The bolometer design parameters are determined by modeling the temperature of the foils from which the absorbing matrix is fabricated by using a two-dimensional time-dependent solution of the heat conduction equation. The resulting design will give a steady-state bolometry capability, with approximately 100 Hz time resolution, while simultaneously providing hundreds of channels of spatial information. No wiring harnesses will be required, as the temperature-rise data will be measured via an IR camera. The resulting spatial data may be used to tomographically investigate the profile of plasmas. 2 figs.

Imaging bolometer

DOEpatents

Wurden, Glen A.

1999-01-01

Radiation-hard, steady-state imaging bolometer. A bolometer employing infrared (IR) imaging of a segmented-matrix absorber of plasma radiation in a cooled-pinhole camera geometry is described. The bolometer design parameters are determined by modeling the temperature of the foils from which the absorbing matrix is fabricated by using a two-dimensional time-dependent solution of the heat conduction equation. The resulting design will give a steady-state bolometry capability, with approximately 100 Hz time resolution, while simultaneously providing hundreds of channels of spatial information. No wiring harnesses will be required, as the temperature-rise data will be measured via an IR camera. The resulting spatial data may be used to tomographically investigate the profile of plasmas.

Person Recognition System Based on a Combination of Body Images from Visible Light and Thermal Cameras.

PubMed

Nguyen, Dat Tien; Hong, Hyung Gil; Kim, Ki Wan; Park, Kang Ryoung

2017-03-16

The human body contains identity information that can be used for the person recognition (verification/recognition) problem. In this paper, we propose a person recognition method using the information extracted from body images. Our research is novel in the following three ways compared to previous studies. First, we use the images of human body for recognizing individuals. To overcome the limitations of previous studies on body-based person recognition that use only visible light images for recognition, we use human body images captured by two different kinds of camera, including a visible light camera and a thermal camera. The use of two different kinds of body image helps us to reduce the effects of noise, background, and variation in the appearance of a human body. Second, we apply a state-of-the art method, called convolutional neural network (CNN) among various available methods, for image features extraction in order to overcome the limitations of traditional hand-designed image feature extraction methods. Finally, with the extracted image features from body images, the recognition task is performed by measuring the distance between the input and enrolled samples. The experimental results show that the proposed method is efficient for enhancing recognition accuracy compared to systems that use only visible light or thermal images of the human body.

Cinematic camera emulation using two-dimensional color transforms

NASA Astrophysics Data System (ADS)

McElvain, Jon S.; Gish, Walter

2015-02-01

For cinematic and episodic productions, on-set look management is an important component of the creative process, and involves iterative adjustments of the set, actors, lighting and camera configuration. Instead of using the professional motion capture device to establish a particular look, the use of a smaller form factor DSLR is considered for this purpose due to its increased agility. Because the spectral response characteristics will be different between the two camera systems, a camera emulation transform is needed to approximate the behavior of the destination camera. Recently, twodimensional transforms have been shown to provide high-accuracy conversion of raw camera signals to a defined colorimetric state. In this study, the same formalism is used for camera emulation, whereby a Canon 5D Mark III DSLR is used to approximate the behavior a Red Epic cinematic camera. The spectral response characteristics for both cameras were measured and used to build 2D as well as 3x3 matrix emulation transforms. When tested on multispectral image databases, the 2D emulation transforms outperform their matrix counterparts, particularly for images containing highly chromatic content.

Recent technology and usage of plastic lenses in image taking objectives

NASA Astrophysics Data System (ADS)

Yamaguchi, Susumu; Sato, Hiroshi; Mori, Nobuyoshi; Kiriki, Toshihiko

2005-09-01

Recently, plastic lenses produced by injection molding are widely used in image taking objectives for digital cameras, camcorders, and mobile phone cameras, because of their suitability for volume production and ease of obtaining an advantage of aspherical surfaces. For digital camera and camcorder objectives, it is desirable that there is no image point variation with the temperature change in spite of employing several plastic lenses. At the same time, due to the shrinking pixel size of solid-state image sensor, there is now a requirement to assemble lenses with high accuracy. In order to satisfy these requirements, we have developed 16 times compact zoom objective for camcorder and 3 times class folded zoom objectives for digital camera, incorporating cemented plastic doublet consisting of a positive lens and a negative lens. Over the last few years, production volumes of camera-equipped mobile phones have increased substantially. Therefore, for mobile phone cameras, the consideration of productivity is more important than ever. For this application, we have developed a 1.3-mega pixels compact camera module with macro function utilizing the advantage of a plastic lens that can be given mechanically functional shape to outer flange part. Its objective consists of three plastic lenses and all critical dimensions related to optical performance can be determined by high precise optical elements. Therefore this camera module is manufactured without optical adjustment in automatic assembling line, and achieves both high productivity and high performance. Reported here are the constructions and the technical topics of image taking objectives described above.

Clinical trials of the prototype Rutherford Appleton Laboratory MWPC positron camera at the Royal Marsden Hospital

NASA Astrophysics Data System (ADS)

Flower, M. A.; Ott, R. J.; Webb, S.; Leach, M. O.; Marsden, P. K.; Clack, R.; Khan, O.; Batty, V.; McCready, V. R.; Bateman, J. E.

1988-06-01

Two clinical trials of the prototype RAL multiwire proportional chamber (MWPC) positron camera were carried out prior to the development of a clinical system with large-area detectors. During the first clinical trial, the patient studies included skeletal imaging using 18F, imaging of brain glucose metabolism using 18F FDG, bone marrow imaging using 52Fe citrate and thyroid imaging with Na 124I. Longitudinal tomograms were produced from the limited-angle data acquisition from the static detectors. During the second clinical trial, transaxial, coronal and sagittal images were produced from the multiview data acquisition. A more detailed thyroid study was performed in which the volume of the functioning thyroid tissue was obtained from the 3D PET image and this volume was used in estimating the radiation dose achieved during radioiodine therapy of patients with thyrotoxicosis. Despite the small field of view of the prototype camera, and the use of smaller than usual amounts of activity administered, the PET images were in most cases comparable with, and in a few cases visually better than, the equivalent planar view using a state-of-the-art gamma camera with a large field of view and routine radiopharmaceuticals.

Versatile microsecond movie camera

NASA Astrophysics Data System (ADS)

Dreyfus, R. W.

1980-03-01

A laboratory-type movie camera is described which satisfies many requirements in the range 1 microsec to 1 sec. The camera consists of a He-Ne laser and compatible state-of-the-art components; the primary components are an acoustooptic modulator, an electromechanical beam deflector, and a video tape system. The present camera is distinct in its operation in that submicrosecond laser flashes freeze the image motion while still allowing the simplicity of electromechanical image deflection in the millisecond range. The gating and pulse delay circuits of an oscilloscope synchronize the modulator and scanner relative to the subject being photographed. The optical table construction and electronic control enhance the camera's versatility and adaptability. The instant replay video tape recording allows for easy synchronization and immediate viewing of the results. Economy is achieved by using off-the-shelf components, optical table construction, and short assembly time.

Solid state television camera (CCD-buried channel)

NASA Technical Reports Server (NTRS)

1976-01-01

The development of an all solid state television camera, which uses a buried channel charge coupled device (CCD) as the image sensor, was undertaken. A 380 x 488 element CCD array is utilized to ensure compatibility with 525 line transmission and display monitor equipment. Specific camera design approaches selected for study and analysis included (a) optional clocking modes for either fast (1/60 second) or normal (1/30 second) frame readout, (b) techniques for the elimination or suppression of CCD blemish effects, and (c) automatic light control and video gain control (i.e., ALC and AGC) techniques to eliminate or minimize sensor overload due to bright objects in the scene. Preferred approaches were determined and integrated into a deliverable solid state TV camera which addressed the program requirements for a prototype qualifiable to space environment conditions.

Solid state television camera (CCD-buried channel), revision 1

NASA Technical Reports Server (NTRS)

1977-01-01

An all solid state television camera was designed which uses a buried channel charge coupled device (CCD) as the image sensor. A 380 x 488 element CCD array is utilized to ensure compatibility with 525-line transmission and display monitor equipment. Specific camera design approaches selected for study and analysis included (1) optional clocking modes for either fast (1/60 second) or normal (1/30 second) frame readout, (2) techniques for the elimination or suppression of CCD blemish effects, and (3) automatic light control and video gain control techniques to eliminate or minimize sensor overload due to bright objects in the scene. Preferred approaches were determined and integrated into a deliverable solid state TV camera which addressed the program requirements for a prototype qualifiable to space environment conditions.

Solid state, CCD-buried channel, television camera study and design

NASA Technical Reports Server (NTRS)

Hoagland, K. A.; Balopole, H.

1976-01-01

An investigation of an all solid state television camera design, which uses a buried channel charge-coupled device (CCD) as the image sensor, was undertaken. A 380 x 488 element CCD array was utilized to ensure compatibility with 525 line transmission and display monitor equipment. Specific camera design approaches selected for study and analysis included (a) optional clocking modes for either fast (1/60 second) or normal (1/30 second) frame readout, (b) techniques for the elimination or suppression of CCD blemish effects, and (c) automatic light control and video gain control techniques to eliminate or minimize sensor overload due to bright objects in the scene. Preferred approaches were determined and integrated into a design which addresses the program requirements for a deliverable solid state TV camera.

Development of an image converter of radical design. [employing solid state electronics towards the production of an advanced engineering model camera system

NASA Technical Reports Server (NTRS)

Irwin, E. L.; Farnsworth, D. L.

1972-01-01

A long term investigation of thin film sensors, monolithic photo-field effect transistors, and epitaxially diffused phototransistors and photodiodes to meet requirements to produce acceptable all solid state, electronically scanned imaging system, led to the production of an advanced engineering model camera which employs a 200,000 element phototransistor array (organized in a matrix of 400 rows by 500 columns) to secure resolution comparable to commercial television. The full investigation is described for the period July 1962 through July 1972, and covers the following broad topics in detail: (1) sensor monoliths; (2) fabrication technology; (3) functional theory; (4) system methodology; and (5) deployment profile. A summary of the work and conclusions are given, along with extensive schematic diagrams of the final solid state imaging system product.

Precise color images a high-speed color video camera system with three intensified sensors

NASA Astrophysics Data System (ADS)

Oki, Sachio; Yamakawa, Masafumi; Gohda, Susumu; Etoh, Takeharu G.

1999-06-01

High speed imaging systems have been used in a large field of science and engineering. Although the high speed camera systems have been improved to high performance, most of their applications are only to get high speed motion pictures. However, in some fields of science and technology, it is useful to get some other information, such as temperature of combustion flame, thermal plasma and molten materials. Recent digital high speed video imaging technology should be able to get such information from those objects. For this purpose, we have already developed a high speed video camera system with three-intensified-sensors and cubic prism image splitter. The maximum frame rate is 40,500 pps (picture per second) at 64 X 64 pixels and 4,500 pps at 256 X 256 pixels with 256 (8 bit) intensity resolution for each pixel. The camera system can store more than 1,000 pictures continuously in solid state memory. In order to get the precise color images from this camera system, we need to develop a digital technique, which consists of a computer program and ancillary instruments, to adjust displacement of images taken from two or three image sensors and to calibrate relationship between incident light intensity and corresponding digital output signals. In this paper, the digital technique for pixel-based displacement adjustment are proposed. Although the displacement of the corresponding circle was more than 8 pixels in original image, the displacement was adjusted within 0.2 pixels at most by this method.

Person Recognition System Based on a Combination of Body Images from Visible Light and Thermal Cameras

PubMed Central

Nguyen, Dat Tien; Hong, Hyung Gil; Kim, Ki Wan; Park, Kang Ryoung

2017-01-01

The human body contains identity information that can be used for the person recognition (verification/recognition) problem. In this paper, we propose a person recognition method using the information extracted from body images. Our research is novel in the following three ways compared to previous studies. First, we use the images of human body for recognizing individuals. To overcome the limitations of previous studies on body-based person recognition that use only visible light images for recognition, we use human body images captured by two different kinds of camera, including a visible light camera and a thermal camera. The use of two different kinds of body image helps us to reduce the effects of noise, background, and variation in the appearance of a human body. Second, we apply a state-of-the art method, called convolutional neural network (CNN) among various available methods, for image features extraction in order to overcome the limitations of traditional hand-designed image feature extraction methods. Finally, with the extracted image features from body images, the recognition task is performed by measuring the distance between the input and enrolled samples. The experimental results show that the proposed method is efficient for enhancing recognition accuracy compared to systems that use only visible light or thermal images of the human body. PMID:28300783

Geiger-mode APD camera system for single-photon 3D LADAR imaging

NASA Astrophysics Data System (ADS)

Entwistle, Mark; Itzler, Mark A.; Chen, Jim; Owens, Mark; Patel, Ketan; Jiang, Xudong; Slomkowski, Krystyna; Rangwala, Sabbir

2012-06-01

The unparalleled sensitivity of 3D LADAR imaging sensors based on single photon detection provides substantial benefits for imaging at long stand-off distances and minimizing laser pulse energy requirements. To obtain 3D LADAR images with single photon sensitivity, we have demonstrated focal plane arrays (FPAs) based on InGaAsP Geiger-mode avalanche photodiodes (GmAPDs) optimized for use at either 1.06 μm or 1.55 μm. These state-of-the-art FPAs exhibit excellent pixel-level performance and the capability for 100% pixel yield on a 32 x 32 format. To realize the full potential of these FPAs, we have recently developed an integrated camera system providing turnkey operation based on FPGA control. This system implementation enables the extremely high frame-rate capability of the GmAPD FPA, and frame rates in excess of 250 kHz (for 0.4 μs range gates) can be accommodated using an industry-standard CameraLink interface in full configuration. Real-time data streaming for continuous acquisition of 2 μs range gate point cloud data with 13-bit time-stamp resolution at 186 kHz frame rates has been established using multiple solid-state storage drives. Range gate durations spanning 4 ns to 10 μs provide broad operational flexibility. The camera also provides real-time signal processing in the form of multi-frame gray-scale contrast images and single-frame time-stamp histograms, and automated bias control has been implemented to maintain a constant photon detection efficiency in the presence of ambient temperature changes. A comprehensive graphical user interface has been developed to provide complete camera control using a simple serial command set, and this command set supports highly flexible end-user customization.

Automated Ground-based Time-lapse Camera Monitoring of West Greenland ice sheet outlet Glaciers: Challenges and Solutions

NASA Astrophysics Data System (ADS)

Ahn, Y.; Box, J. E.; Balog, J.; Lewinter, A.

2008-12-01

Monitoring Greenland outlet glaciers using remotely sensed data has drawn a great attention in earth science communities for decades and time series analysis of sensory data has provided important variability information of glacier flow by detecting speed and thickness changes, tracking features and acquiring model input. Thanks to advancements of commercial digital camera technology and increased solid state storage, we activated automatic ground-based time-lapse camera stations with high spatial/temporal resolution in west Greenland outlet and collected one-hour interval data continuous for more than one year at some but not all sites. We believe that important information of ice dynamics are contained in these data and that terrestrial mono-/stereo-photogrammetry can provide theoretical/practical fundamentals in data processing along with digital image processing techniques. Time-lapse images over periods in west Greenland indicate various phenomenon. Problematic is rain, snow, fog, shadows, freezing of water on camera enclosure window, image over-exposure, camera motion, sensor platform drift, and fox chewing of instrument cables, and the pecking of plastic window by ravens. Other problems include: feature identification, camera orientation, image registration, feature matching in image pairs, and feature tracking. Another obstacle is that non-metric digital camera contains large distortion to be compensated for precise photogrammetric use. Further, a massive number of images need to be processed in a way that is sufficiently computationally efficient. We meet these challenges by 1) identifying problems in possible photogrammetric processes, 2) categorizing them based on feasibility, and 3) clarifying limitation and alternatives, while emphasizing displacement computation and analyzing regional/temporal variability. We experiment with mono and stereo photogrammetric techniques in the aide of automatic correlation matching for efficiently handling the enormous data volumes.

Making Connections with Digital Data

ERIC Educational Resources Information Center

Leonard, William; Bassett, Rick; Clinger, Alicia; Edmondson, Elizabeth; Horton, Robert

2004-01-01

State-of-the-art digital cameras open up enormous possibilities in the science classroom, especially when used as data collectors. Because most high school students are not fully formal thinkers, the digital camera can provide a much richer learning experience than traditional observation. Data taken through digital images can make the…

Assessment of the metrological performance of an in situ storage image sensor ultra-high speed camera for full-field deformation measurements

NASA Astrophysics Data System (ADS)

Rossi, Marco; Pierron, Fabrice; Forquin, Pascal

2014-02-01

Ultra-high speed (UHS) cameras allow us to acquire images typically up to about 1 million frames s-1 for a full spatial resolution of the order of 1 Mpixel. Different technologies are available nowadays to achieve these performances, an interesting one is the so-called in situ storage image sensor architecture where the image storage is incorporated into the sensor chip. Such an architecture is all solid state and does not contain movable devices as occurs, for instance, in the rotating mirror UHS cameras. One of the disadvantages of this system is the low fill factor (around 76% in the vertical direction and 14% in the horizontal direction) since most of the space in the sensor is occupied by memory. This peculiarity introduces a series of systematic errors when the camera is used to perform full-field strain measurements. The aim of this paper is to develop an experimental procedure to thoroughly characterize the performance of such kinds of cameras in full-field deformation measurement and identify the best operative conditions which minimize the measurement errors. A series of tests was performed on a Shimadzu HPV-1 UHS camera first using uniform scenes and then grids under rigid movements. The grid method was used as full-field measurement optical technique here. From these tests, it has been possible to appropriately identify the camera behaviour and utilize this information to improve actual measurements.

The PMC-Turbo Balloon Mission to Study Gravity Waves and Turbulence through High-Resolution Imaging of Polar Mesospheric Clouds

NASA Astrophysics Data System (ADS)

Williams, B. P.; Kjellstrand, B.; Jones, G.; Reimuller, J. D.; Fritts, D. C.; Miller, A.; Geach, C.; Limon, M.; Hanany, S.; Kaifler, B.; Wang, L.; Taylor, M. J.

2017-12-01

PMC-Turbo is a NASA long-duration, high-altitude balloon mission that will deploy 7 high-resolution cameras to image polar mesospheric clouds (PMC) and measure gravity wave breakdown and turbulence. The mission has been enhanced by the addition of the DLR Balloon Lidar Experiment (BOLIDE) and an OH imager from Utah State University. This instrument suite will provide high horizontal and vertical resolution of the wave-modified PMC structure along a several thousand kilometer flight track. We have requested a flight from Kiruna, Sweden to Canada in June 2017 or McMurdo Base, Antarctica in Dec 2017. Three of the PMC camera systems were deployed on an aircraft and two tomographic ground sites for the High Level campaign in Canada in June/July 2017. On several nights the cameras observed PMC's with strong gravity wave breaking signatures. One PMC camera will piggyback on the Super Tiger mission scheduled to be launched in Dec 2017 from McMurdo, so we will obtain PMC images and wave/turbulence data from both the northern and southern hemispheres.

Achieving sub-millimetre precision with a solid-state full-field heterodyning range imaging camera

NASA Astrophysics Data System (ADS)

Dorrington, A. A.; Cree, M. J.; Payne, A. D.; Conroy, R. M.; Carnegie, D. A.

2007-09-01

We have developed a full-field solid-state range imaging system capable of capturing range and intensity data simultaneously for every pixel in a scene with sub-millimetre range precision. The system is based on indirect time-of-flight measurements by heterodyning intensity-modulated illumination with a gain modulation intensified digital video camera. Sub-millimetre precision to beyond 5 m and 2 mm precision out to 12 m has been achieved. In this paper, we describe the new sub-millimetre class range imaging system in detail, and review the important aspects that have been instrumental in achieving high precision ranging. We also present the results of performance characterization experiments and a method of resolving the range ambiguity problem associated with homodyne and heterodyne ranging systems.

Miniaturized unified imaging system using bio-inspired fluidic lens

NASA Astrophysics Data System (ADS)

Tsai, Frank S.; Cho, Sung Hwan; Qiao, Wen; Kim, Nam-Hyong; Lo, Yu-Hwa

2008-08-01

Miniaturized imaging systems have become ubiquitous as they are found in an ever-increasing number of devices, such as cellular phones, personal digital assistants, and web cameras. Until now, the design and fabrication methodology of such systems have not been significantly different from conventional cameras. The only established method to achieve focusing is by varying the lens distance. On the other hand, the variable-shape crystalline lens found in animal eyes offers inspiration for a more natural way of achieving an optical system with high functionality. Learning from the working concepts of the optics in the animal kingdom, we developed bio-inspired fluidic lenses for a miniature universal imager with auto-focusing, macro, and super-macro capabilities. Because of the enormous dynamic range of fluidic lenses, the miniature camera can even function as a microscope. To compensate for the image quality difference between the central vision and peripheral vision and the shape difference between a solid-state image sensor and a curved retina, we adopted a hybrid design consisting of fluidic lenses for tunability and fixed lenses for aberration and color dispersion correction. A design of the world's smallest surgical camera with 3X optical zoom capabilities is also demonstrated using the approach of hybrid lenses.

Evolutionary Fuzzy Block-Matching-Based Camera Raw Image Denoising.

PubMed

Yang, Chin-Chang; Guo, Shu-Mei; Tsai, Jason Sheng-Hong

2017-09-01

An evolutionary fuzzy block-matching-based image denoising algorithm is proposed to remove noise from a camera raw image. Recently, a variance stabilization transform is widely used to stabilize the noise variance, so that a Gaussian denoising algorithm can be used to remove the signal-dependent noise in camera sensors. However, in the stabilized domain, the existed denoising algorithm may blur too much detail. To provide a better estimate of the noise-free signal, a new block-matching approach is proposed to find similar blocks by the use of a type-2 fuzzy logic system (FLS). Then, these similar blocks are averaged with the weightings which are determined by the FLS. Finally, an efficient differential evolution is used to further improve the performance of the proposed denoising algorithm. The experimental results show that the proposed denoising algorithm effectively improves the performance of image denoising. Furthermore, the average performance of the proposed method is better than those of two state-of-the-art image denoising algorithms in subjective and objective measures.

Robust and adaptive band-to-band image transform of UAS miniature multi-lens multispectral camera

NASA Astrophysics Data System (ADS)

Jhan, Jyun-Ping; Rau, Jiann-Yeou; Haala, Norbert

2018-03-01

Utilizing miniature multispectral (MS) or hyperspectral (HS) cameras by mounting them on an Unmanned Aerial System (UAS) has the benefits of convenience and flexibility to collect remote sensing imagery for precision agriculture, vegetation monitoring, and environment investigation applications. Most miniature MS cameras adopt a multi-lens structure to record discrete MS bands of visible and invisible information. The differences in lens distortion, mounting positions, and viewing angles among lenses mean that the acquired original MS images have significant band misregistration errors. We have developed a Robust and Adaptive Band-to-Band Image Transform (RABBIT) method for dealing with the band co-registration of various types of miniature multi-lens multispectral cameras (Mini-MSCs) to obtain band co-registered MS imagery for remote sensing applications. The RABBIT utilizes modified projective transformation (MPT) to transfer the multiple image geometry of a multi-lens imaging system to one sensor geometry, and combines this with a robust and adaptive correction (RAC) procedure to correct several systematic errors and to obtain sub-pixel accuracy. This study applies three state-of-the-art Mini-MSCs to evaluate the RABBIT method's performance, specifically the Tetracam Miniature Multiple Camera Array (MiniMCA), Micasense RedEdge, and Parrot Sequoia. Six MS datasets acquired at different target distances and dates, and locations are also applied to prove its reliability and applicability. Results prove that RABBIT is feasible for different types of Mini-MSCs with accurate, robust, and rapid image processing efficiency.

Advances in Heavy Ion Beam Probe Technology and Operation on MST

NASA Astrophysics Data System (ADS)

Demers, D. R.; Connor, K. A.; Schoch, P. M.; Radke, R. J.; Anderson, J. K.; Craig, D.; den Hartog, D. J.

2003-10-01

A technique to map the magnetic field of a plasma via spectral imaging is being developed with the Heavy Ion Beam Probe on the Madison Symmetric Torus. The technique will utilize two-dimensional images of the ion beam in the plasma, acquired by two CCD cameras, to generate a three-dimensional reconstruction of the beam trajectory. This trajectory, and the known beam ion mass, energy and charge-state, will be used to determine the magnetic field of the plasma. A suitable emission line has not yet been observed since radiation from the MST plasma is both broadband and intense. An effort to raise the emission intensity from the ion beam by increasing beam focus and current has been undertaken. Simulations of the accelerator ion optics and beam characteristics led to a technique, confirmed by experiment, that achieves a narrower beam and marked increase in ion current near the plasma surface. The improvements arising from these simulations will be discussed. Realization of the magnetic field mapping technique is contingent upon accurate reconstruction of the beam trajectory from the camera images. Simulations of two camera CCD images, including the interior of MST, its various landmarks and beam trajectories have been developed. These simulations accept user input such as camera locations, resolution via pixellization and noise. The quality of the images simulated with these and other variables will help guide the selection of viewing port pairs, image size and camera specifications. The results of these simulations will be presented.

Vision-based control for flight relative to dynamic environments

NASA Astrophysics Data System (ADS)

Causey, Ryan Scott

The concept of autonomous systems has been considered an enabling technology for a diverse group of military and civilian applications. The current direction for autonomous systems is increased capabilities through more advanced systems that are useful for missions that require autonomous avoidance, navigation, tracking, and docking. To facilitate this level of mission capability, passive sensors, such as cameras, and complex software are added to the vehicle. By incorporating an on-board camera, visual information can be processed to interpret the surroundings. This information allows decision making with increased situational awareness without the cost of a sensor signature, which is critical in military applications. The concepts presented in this dissertation facilitate the issues inherent to vision-based state estimation of moving objects for a monocular camera configuration. The process consists of several stages involving image processing such as detection, estimation, and modeling. The detection algorithm segments the motion field through a least-squares approach and classifies motions not obeying the dominant trend as independently moving objects. An approach to state estimation of moving targets is derived using a homography approach. The algorithm requires knowledge of the camera motion, a reference motion, and additional feature point geometry for both the target and reference objects. The target state estimates are then observed over time to model the dynamics using a probabilistic technique. The effects of uncertainty on state estimation due to camera calibration are considered through a bounded deterministic approach. The system framework focuses on an aircraft platform of which the system dynamics are derived to relate vehicle states to image plane quantities. Control designs using standard guidance and navigation schemes are then applied to the tracking and homing problems using the derived state estimation. Four simulations are implemented in MATLAB that build on the image concepts present in this dissertation. The first two simulations deal with feature point computations and the effects of uncertainty. The third simulation demonstrates the open-loop estimation of a target ground vehicle in pursuit whereas the four implements a homing control design for the Autonomous Aerial Refueling (AAR) using target estimates as feedback.

Fusion of Building Information and Range Imaging for Autonomous Location Estimation in Indoor Environments

PubMed Central

Kohoutek, Tobias K.; Mautz, Rainer; Wegner, Jan D.

2013-01-01

We present a novel approach for autonomous location estimation and navigation in indoor environments using range images and prior scene knowledge from a GIS database (CityGML). What makes this task challenging is the arbitrary relative spatial relation between GIS and Time-of-Flight (ToF) range camera further complicated by a markerless configuration. We propose to estimate the camera's pose solely based on matching of GIS objects and their detected location in image sequences. We develop a coarse-to-fine matching strategy that is able to match point clouds without any initial parameters. Experiments with a state-of-the-art ToF point cloud show that our proposed method delivers an absolute camera position with decimeter accuracy, which is sufficient for many real-world applications (e.g., collision avoidance). PMID:23435055

Micro-polarimetry for pre-clinical diagnostics of pathological changes in human tissues

NASA Astrophysics Data System (ADS)

Golnik, Andrzej; Golnik, Natalia; Pałko, Tadeusz; Sołtysiński, Tomasz

2008-05-01

The paper presents a practical study of several methods of image analysis applied to polarimetric images of regular and malignant human tissues. The images of physiological and pathologically changed tissues from body and cervix of uterus, intestine, kidneys and breast were recorded in transmitted light of different polarization state. The set up of the conventional optical microscope with CCD camera and rotating polarizer's were used for analysis of the polarization state of the light transmitted through the tissue slice for each pixel of the camera image. The set of images corresponding to the different coefficients of the Stockes vectors, a 3×3 subset of the Mueller matrix as well as the maps of the magnitude and in-plane direction of the birefringent components in the sample were calculated. Then, the statistical analysis and the Fourier transform as well as the autocorrelation methods were used to analyze spatial distribution of birefringent elements in the tissue samples. For better recognition of tissue state we proposed a novel method that takes advantage of multiscale image data decomposition The results were used for selection of the optical characteristics with significantly different values for regular and malignant tissues.

Image Intensifier Modules For Use With Commercially Available Solid State Cameras

NASA Astrophysics Data System (ADS)

Murphy, Howard; Tyler, Al; Lake, Donald W.

1989-04-01

A modular approach to design has contributed greatly to the success of the family of machine vision video equipment produced by EG&G Reticon during the past several years. Internal modularity allows high-performance area (matrix) and line scan cameras to be assembled with two or three electronic subassemblies with very low labor costs, and permits camera control and interface circuitry to be realized by assemblages of various modules suiting the needs of specific applications. Product modularity benefits equipment users in several ways. Modular matrix and line scan cameras are available in identical enclosures (Fig. 1), which allows enclosure components to be purchased in volume for economies of scale and allows field replacement or exchange of cameras within a customer-designed system to be easily accomplished. The cameras are optically aligned (boresighted) at final test; modularity permits optical adjustments to be made with the same precise test equipment for all camera varieties. The modular cameras contain two, or sometimes three, hybrid microelectronic packages (Fig. 2). These rugged and reliable "submodules" perform all of the electronic operations internal to the camera except for the job of image acquisition performed by the monolithic image sensor. Heat produced by electrical power dissipation in the electronic modules is conducted through low resistance paths to the camera case by the metal plates, which results in a thermally efficient and environmentally tolerant camera with low manufacturing costs. A modular approach has also been followed in design of the camera control, video processor, and computer interface accessory called the Formatter (Fig. 3). This unit can be attached directly onto either a line scan or matrix modular camera to form a self-contained units, or connected via a cable to retain the advantages inherent to a small, light weight, and rugged image sensing component. Available modules permit the bus-structured Formatter to be configured as required by a specific camera application. Modular line and matrix scan cameras incorporating sensors with fiber optic faceplates (Fig 4) are also available. These units retain the advantages of interchangeability, simple construction, ruggedness, and optical precision offered by the more common lens input units. Fiber optic faceplate cameras are used for a wide variety of applications. A common usage involves mating of the Reticon-supplied camera to a customer-supplied intensifier tube for low light level and/or short exposure time situations.

Adding polarimetric imaging to depth map using improved light field camera 2.0 structure

NASA Astrophysics Data System (ADS)

Zhang, Xuanzhe; Yang, Yi; Du, Shaojun; Cao, Yu

2017-06-01

Polarization imaging plays an important role in various fields, especially for skylight navigation and target identification, whose imaging system is always required to be designed with high resolution, broad band, and single-lens structure. This paper describe such a imaging system based on light field 2.0 camera structure, which can calculate the polarization state and depth distance from reference plane for every objet point within a single shot. This structure, including a modified main lens, a multi-quadrants Polaroid, a honeycomb-liked micro lens array, and a high resolution CCD, is equal to an "eyes array", with 3 or more polarization imaging "glasses" in front of each "eye". Therefore, depth can be calculated by matching the relative offset of corresponding patch on neighboring "eyes", while polarization state by its relative intensity difference, and their resolution will be approximately equal to each other. An application on navigation under clear sky shows that this method has a high accuracy and strong robustness.

Possibilities of Processing Archival Photogrammetric Images Captured by Rollei 6006 Metric Camera Using Current Method

NASA Astrophysics Data System (ADS)

Dlesk, A.; Raeva, P.; Vach, K.

2018-05-01

Processing of analog photogrammetric negatives using current methods brings new challenges and possibilities, for example, creation of a 3D model from archival images which enables the comparison of historical state and current state of cultural heritage objects. The main purpose of this paper is to present possibilities of processing archival analog images captured by photogrammetric camera Rollei 6006 metric. In 1994, the Czech company EuroGV s.r.o. carried out photogrammetric measurements of former limestone quarry the Great America located in the Central Bohemian Region in the Czech Republic. All the negatives of photogrammetric images, complete documentation, coordinates of geodetically measured ground control points, calibration reports and external orientation of images calculated in the Combined Adjustment Program are preserved and were available for the current processing. Negatives of images were scanned and processed using structure from motion method (SfM). The result of the research is a statement of what accuracy is possible to expect from the proposed methodology using Rollei metric images originally obtained for terrestrial intersection photogrammetry while adhering to the proposed methodology.

Towards Kilo-Hertz 6-DoF Visual Tracking Using an Egocentric Cluster of Rolling Shutter Cameras.

PubMed

Bapat, Akash; Dunn, Enrique; Frahm, Jan-Michael

2016-11-01

To maintain a reliable registration of the virtual world with the real world, augmented reality (AR) applications require highly accurate, low-latency tracking of the device. In this paper, we propose a novel method for performing this fast 6-DOF head pose tracking using a cluster of rolling shutter cameras. The key idea is that a rolling shutter camera works by capturing the rows of an image in rapid succession, essentially acting as a high-frequency 1D image sensor. By integrating multiple rolling shutter cameras on the AR device, our tracker is able to perform 6-DOF markerless tracking in a static indoor environment with minimal latency. Compared to state-of-the-art tracking systems, this tracking approach performs at significantly higher frequency, and it works in generalized environments. To demonstrate the feasibility of our system, we present thorough evaluations on synthetically generated data with tracking frequencies reaching 56.7 kHz. We further validate the method's accuracy on real-world images collected from a prototype of our tracking system against ground truth data using standard commodity GoPro cameras capturing at 120 Hz frame rate.

Technical and instrumental prerequisites for single-port laparoscopic solo surgery: state of art.

PubMed

Kim, Say-June; Lee, Sang Chul

2015-04-21

With the aid of advanced surgical techniques and instruments, single-port laparoscopic surgery (SPLS) can be accomplished with just two surgical members: an operator and a camera assistant. Under these circumstances, the reasonable replacement of a human camera assistant by a mechanical camera holder has resulted in a new surgical procedure termed single-port solo surgery (SPSS). In SPSS, the fixation and coordinated movement of a camera held by mechanical devices provides fixed and stable operative images that are under the control of the operator. Therefore, SPSS primarily benefits from the provision of the operator's eye-to-hand coordination. Because SPSS is an intuitive modification of SPLS, the indications for SPSS are the same as those for SPLS. Though SPSS necessitates more actions than the surgery with a human assistant, these difficulties seem to be easily overcome by the greater provision of static operative images and the need for less lens cleaning and repositioning of the camera. When the operation is expected to be difficult and demanding, the SPSS process could be assisted by the addition of another instrument holder besides the camera holder.

STS-31 crew activity on the middeck of the Earth-orbiting Discovery, OV-103

NASA Image and Video Library

1990-04-29

STS031-05-002 (24-29 April 1990) --- A 35mm camera with a "fish eye" lens captured this high angle image on Discovery's middeck. Astronaut Kathryn D. Sullivan works with the IMAX camera in foreground, while Astronaut Steven A. Hawley consults a checklist in corner. An Arriflex motion picture camera records student ion arc experiment in apparatus mounted on stowage locker. The experiment was the project of Gregory S. Peterson, currently a student at Utah State University.

Development of the SEASIS instrument for SEDSAT

NASA Technical Reports Server (NTRS)

Maier, Mark W.

1996-01-01

Two SEASIS experiment objectives are key: take images that allow three axis attitude determination and take multi-spectral images of the earth. During the tether mission it is also desirable to capture images for the recoiling tether from the endmass perspective (which has never been observed). SEASIS must store all its imagery taken during the tether mission until the earth downlink can be established. SEASIS determines attitude with a panoramic camera and performs earth observation with a telephoto lens camera. Camera video is digitized, compressed, and stored in solid state memory. These objectives are addressed through the following architectural choices: (1) A camera system using a Panoramic Annular Lens (PAL). This lens has a 360 deg. azimuthal field of view by a +45 degree vertical field measured from a plan normal to the lens boresight axis. It has been shown in Mr. Mark Steadham's UAH M.S. thesis that his camera can determine three axis attitude anytime the earth and one other recognizable celestial object (for example, the sun) is in the field of view. This will be essentially all the time during tether deployment. (2) A second camera system using telephoto lens and filter wheel. The camera is a black and white standard video camera. The filters are chosen to cover the visible spectral bands of remote sensing interest. (3) A processor and mass memory arrangement linked to the cameras. Video signals from the cameras are digitized, compressed in the processor, and stored in a large static RAM bank. The processor is a multi-chip module consisting of a T800 Transputer and three Zoran floating point Digital Signal Processors. This processor module was supplied under ARPA contract by the Space Computer Corporation to demonstrate its use in space.

Very High-Speed Digital Video Capability for In-Flight Use

NASA Technical Reports Server (NTRS)

Corda, Stephen; Tseng, Ting; Reaves, Matthew; Mauldin, Kendall; Whiteman, Donald

2006-01-01

digital video camera system has been qualified for use in flight on the NASA supersonic F-15B Research Testbed aircraft. This system is capable of very-high-speed color digital imaging at flight speeds up to Mach 2. The components of this system have been ruggedized and shock-mounted in the aircraft to survive the severe pressure, temperature, and vibration of the flight environment. The system includes two synchronized camera subsystems installed in fuselage-mounted camera pods (see Figure 1). Each camera subsystem comprises a camera controller/recorder unit and a camera head. The two camera subsystems are synchronized by use of an MHub(TradeMark) synchronization unit. Each camera subsystem is capable of recording at a rate up to 10,000 pictures per second (pps). A state-of-the-art complementary metal oxide/semiconductor (CMOS) sensor in the camera head has a maximum resolution of 1,280 1,024 pixels at 1,000 pps. Exposure times of the electronic shutter of the camera range from 1/200,000 of a second to full open. The recorded images are captured in a dynamic random-access memory (DRAM) and can be downloaded directly to a personal computer or saved on a compact flash memory card. In addition to the high-rate recording of images, the system can display images in real time at 30 pps. Inter Range Instrumentation Group (IRIG) time code can be inserted into the individual camera controllers or into the M-Hub unit. The video data could also be used to obtain quantitative, three-dimensional trajectory information. The first use of this system was in support of the Space Shuttle Return to Flight effort. Data were needed to help in understanding how thermally insulating foam is shed from a space shuttle external fuel tank during launch. The cameras captured images of simulated external tank debris ejected from a fixture mounted under the centerline of the F-15B aircraft. Digital video was obtained at subsonic and supersonic flight conditions, including speeds up to Mach 2 and altitudes up to 50,000 ft (15.24 km). The digital video was used to determine the structural survivability of the debris in a real flight environment and quantify the aerodynamic trajectories of the debris.

HUBBLE'S PANORAMIC PICTURE OF COMET SHOEMAKER-LEVY 9

NASA Technical Reports Server (NTRS)

2002-01-01

Infrared image shows bright spot, aftermath of the impact of the first fragment of Comet Shoemaker-Levy 9 on the planet Jupiter. The image was made using an infrared camera built by Ohio State University and the 4-meter telescope at the Cerro Tololo Interamerican Observatory (CTIO) at La Serena, Chile. Credit: John Spencer (Lowell Observatory), Darren Depoy (Ohio State University), CTIO.

Visible-regime polarimetric imager: a fully polarimetric, real-time imaging system.

PubMed

Barter, James D; Thompson, Harold R; Richardson, Christine L

2003-03-20

A fully polarimetric optical camera system has been constructed to obtain polarimetric information simultaneously from four synchronized charge-coupled device imagers at video frame rates of 60 Hz and a resolution of 640 x 480 pixels. The imagers view the same scene along the same optical axis by means of a four-way beam-splitting prism similar to ones used for multiple-imager, common-aperture color TV cameras. Appropriate polarizing filters in front of each imager provide the polarimetric information. Mueller matrix analysis of the polarimetric response of the prism, analyzing filters, and imagers is applied to the detected intensities in each imager as a function of the applied state of polarization over a wide range of linear and circular polarization combinations to obtain an average polarimetric calibration consistent to approximately 2%. Higher accuracies can be obtained by improvement of the polarimetric modeling of the splitting prism and by implementation of a pixel-by-pixel calibration.

Teaching physics and understanding infrared thermal imaging

NASA Astrophysics Data System (ADS)

Vollmer, Michael; Möllmann, Klaus-Peter

2017-08-01

Infrared thermal imaging is a very rapidly evolving field. The latest trends are small smartphone IR camera accessories, making infrared imaging a widespread and well-known consumer product. Applications range from medical diagnosis methods via building inspections and industrial predictive maintenance etc. also to visualization in the natural sciences. Infrared cameras do allow qualitative imaging and visualization but also quantitative measurements of the surface temperatures of objects. On the one hand, they are a particularly suitable tool to teach optics and radiation physics and many selected topics in different fields of physics, on the other hand there is an increasing need of engineers and physicists who understand these complex state of the art photonics systems. Therefore students must also learn and understand the physics underlying these systems.

Automatic treatment of flight test images using modern tools: SAAB and Aeritalia joint approach

NASA Astrophysics Data System (ADS)

Kaelldahl, A.; Duranti, P.

The use of onboard cine cameras, as well as that of on ground cinetheodolites, is very popular in flight tests. The high resolution of film and the high frame rate of cinecameras are still not exceeded by video technology. Video technology can successfully enter the flight test scenario once the availability of solid-state optical sensors dramatically reduces the dimensions, and weight of TV cameras, thus allowing to locate them in positions compatible with space or operational limitations (e.g., HUD cameras). A proper combination of cine and video cameras is the typical solution for a complex flight test program. The output of such devices is very helpful in many flight areas. Several sucessful applications of this technology are summarized. Analysis of the large amount of data produced (frames of images) requires a very long time. The analysis is normally carried out manually. In order to improve the situation, in the last few years, several flight test centers have devoted their attention to possible techniques which allow for quicker and more effective image treatment.

Gaspra Approach Sequence

NASA Image and Video Library

1996-01-29

This montage of 11 images taken by NASA Galileo spacecraft as it flew by the asteroid Gaspra on Oct. 1991, shows Gaspra growing progressively larger in the field of view of Galileo solid-state imaging camera as the spacecraft approached the asteroid. http://photojournal.jpl.nasa.gov/catalog/PIA00079

Lytro camera technology: theory, algorithms, performance analysis

NASA Astrophysics Data System (ADS)

Georgiev, Todor; Yu, Zhan; Lumsdaine, Andrew; Goma, Sergio

2013-03-01

The Lytro camera is the first implementation of a plenoptic camera for the consumer market. We consider it a successful example of the miniaturization aided by the increase in computational power characterizing mobile computational photography. The plenoptic camera approach to radiance capture uses a microlens array as an imaging system focused on the focal plane of the main camera lens. This paper analyzes the performance of Lytro camera from a system level perspective, considering the Lytro camera as a black box, and uses our interpretation of Lytro image data saved by the camera. We present our findings based on our interpretation of Lytro camera file structure, image calibration and image rendering; in this context, artifacts and final image resolution are discussed.

Image quality prediction - An aid to the Viking lander imaging investigation on Mars

NASA Technical Reports Server (NTRS)

Huck, F. O.; Wall, S. D.

1976-01-01

Image quality criteria and image quality predictions are formulated for the multispectral panoramic cameras carried by the Viking Mars landers. Image quality predictions are based on expected camera performance, Mars surface radiance, and lighting and viewing geometry (fields of view, Mars lander shadows, solar day-night alternation), and are needed in diagnosis of camera performance, in arriving at a preflight imaging strategy, and revision of that strategy should the need arise. Landing considerations, camera control instructions, camera control logic, aspects of the imaging process (spectral response, spatial response, sensitivity), and likely problems are discussed. Major concerns include: degradation of camera response by isotope radiation, uncertainties in lighting and viewing geometry and in landing site local topography, contamination of camera window by dust abrasion, and initial errors in assigning camera dynamic ranges (gains and offsets).

Of Detection Limits and Effective Mitigation: The Use of Infrared Cameras for Methane Leak Detection

NASA Astrophysics Data System (ADS)

Ravikumar, A. P.; Wang, J.; McGuire, M.; Bell, C.; Brandt, A. R.

2017-12-01

Mitigating methane emissions, a short-lived and potent greenhouse gas, is critical to limiting global temperature rise to two degree Celsius as outlined in the Paris Agreement. A major source of anthropogenic methane emissions in the United States is the oil and gas sector. To this effect, state and federal governments have recommended the use of optical gas imaging systems in periodic leak detection and repair (LDAR) surveys to detect for fugitive emissions or leaks. The most commonly used optical gas imaging systems (OGI) are infrared cameras. In this work, we systematically evaluate the limits of infrared (IR) camera based OGI system for use in methane leak detection programs. We analyze the effect of various parameters that influence the minimum detectable leak rates of infrared cameras. Blind leak detection tests were carried out at the Department of Energy's MONITOR natural gas test-facility in Fort Collins, CO. Leak sources included natural gas wellheads, separators, and tanks. With an EPA mandated 60 g/hr leak detection threshold for IR cameras, we test leak rates ranging from 4 g/hr to over 350 g/hr at imaging distances between 5 ft and 70 ft from the leak source. We perform these experiments over the course of a week, encompassing a wide range of wind and weather conditions. Using repeated measurements at a given leak rate and imaging distance, we generate detection probability curves as a function of leak-size for various imaging distances, and measurement conditions. In addition, we estimate the median detection threshold - leak-size at which the probability of detection is 50% - under various scenarios to reduce uncertainty in mitigation effectiveness. Preliminary analysis shows that the median detection threshold varies from 3 g/hr at an imaging distance of 5 ft to over 150 g/hr at 50 ft (ambient temperature: 80 F, winds < 4 m/s). Results from this study can be directly used to improve OGI based LDAR protocols and reduce uncertainty in estimated mitigation effectiveness. Furthermore, detection limits determined in this study can be used as standards to compare new detection technologies.

4K x 2K pixel color video pickup system

NASA Astrophysics Data System (ADS)

Sugawara, Masayuki; Mitani, Kohji; Shimamoto, Hiroshi; Fujita, Yoshihiro; Yuyama, Ichiro; Itakura, Keijirou

1998-12-01

This paper describes the development of an experimental super- high-definition color video camera system. During the past several years there has been much interest in super-high- definition images as the next generation image media. One of the difficulties in implementing a super-high-definition motion imaging system is constructing the image-capturing section (camera). Even the state-of-the-art semiconductor technology can not realize the image sensor which has enough pixels and output data rate for super-high-definition images. The present study is an attempt to fill the gap in this respect. The authors intend to solve the problem by using new imaging method in which four HDTV sensors are attached on a new color separation optics so that their pixel sample pattern forms checkerboard pattern. A series of imaging experiments demonstrate that this technique is an effective approach to capturing super-high-definition moving images in the present situation where no image sensors exist for such images.

Motion Estimation Utilizing Range Detection-Enhanced Visual Odometry

NASA Technical Reports Server (NTRS)

Morris, Daniel Dale (Inventor); Chang, Hong (Inventor); Friend, Paul Russell (Inventor); Chen, Qi (Inventor); Graf, Jodi Seaborn (Inventor)

2016-01-01

A motion determination system is disclosed. The system may receive a first and a second camera image from a camera, the first camera image received earlier than the second camera image. The system may identify corresponding features in the first and second camera images. The system may receive range data comprising at least one of a first and a second range data from a range detection unit, corresponding to the first and second camera images, respectively. The system may determine first positions and the second positions of the corresponding features using the first camera image and the second camera image. The first positions or the second positions may be determined by also using the range data. The system may determine a change in position of the machine based on differences between the first and second positions, and a VO-based velocity of the machine based on the determined change in position.

An imaging system for PLIF/Mie measurements for a combusting flow

NASA Technical Reports Server (NTRS)

Wey, C. C.; Ghorashi, B.; Marek, C. J.; Wey, C.

1990-01-01

The equipment required to establish an imaging system can be divided into four parts: (1) the light source and beam shaping optics; (2) camera and recording; (3) image acquisition and processing; and (4) computer and output systems. A pulsed, Nd:YAG-pummped, frequency-doubled dye laser which can freeze motion in the flowfield is used for an illumination source. A set of lenses is used to form the laser beam into a sheet. The induced fluorescence is collected by an UV-enhanced lens and passes through an UV-enhanced microchannel plate intensifier which is optically coupled to a gated solid state CCD camera. The output of the camera is simultaneously displayed on a monitor and recorded on either a laser videodisc set of a Super VHS VCR. This videodisc set is controlled by a minicomputer via a connection to the RS-232C interface terminals. The imaging system is connected to the host computer by a bus repeater and can be multiplexed between four video input sources. Sample images from a planar shear layer experiment are presented to show the processing capability of the imaging system with the host computer.

Dual-polarized light-field imaging micro-system via a liquid-crystal microlens array for direct three-dimensional observation.

PubMed

Xin, Zhaowei; Wei, Dong; Xie, Xingwang; Chen, Mingce; Zhang, Xinyu; Liao, Jing; Wang, Haiwei; Xie, Changsheng

2018-02-19

Light-field imaging is a crucial and straightforward way of measuring and analyzing surrounding light worlds. In this paper, a dual-polarized light-field imaging micro-system based on a twisted nematic liquid-crystal microlens array (TN-LCMLA) for direct three-dimensional (3D) observation is fabricated and demonstrated. The prototyped camera has been constructed by integrating a TN-LCMLA with a common CMOS sensor array. By switching the working state of the TN-LCMLA, two orthogonally polarized light-field images can be remapped through the functioned imaging sensors. The imaging micro-system in conjunction with the electric-optical microstructure can be used to perform polarization and light-field imaging, simultaneously. Compared with conventional plenoptic cameras using liquid-crystal microlens array, the polarization-independent light-field images with a high image quality can be obtained in the arbitrary polarization state selected. We experimentally demonstrate characters including a relatively wide operation range in the manipulation of incident beams and the multiple imaging modes, such as conventional two-dimensional imaging, light-field imaging, and polarization imaging. Considering the obvious features of the TN-LCMLA, such as very low power consumption, providing multiple imaging modes mentioned, simple and low-cost manufacturing, the imaging micro-system integrated with this kind of liquid-crystal microstructure driven electrically presents the potential capability of directly observing a 3D object in typical scattering media.

Use of a Non-Metric Digital Camera for Tree Stem Evaluation

Treesearch

Neil Clark; Randolph H. Wynne; Daniel L. Schmoldt; Philip A. Araman; Matthew F. Winn

1998-01-01

We are investigating the use of a commercially-available solid-state matrix camera as a dendrometer for tree stem measurements. Thirty-two images of four hardwood stems were used to measure 54 diameters at various heights on the stems ranging from 1.4 m to 21 m. These measurements were compared to caliper measurements taken at the same heights. The percent inaccuracy...

Application of Sensor Fusion to Improve Uav Image Classification

NASA Astrophysics Data System (ADS)

Jabari, S.; Fathollahi, F.; Zhang, Y.

2017-08-01

Image classification is one of the most important tasks of remote sensing projects including the ones that are based on using UAV images. Improving the quality of UAV images directly affects the classification results and can save a huge amount of time and effort in this area. In this study, we show that sensor fusion can improve image quality which results in increasing the accuracy of image classification. Here, we tested two sensor fusion configurations by using a Panchromatic (Pan) camera along with either a colour camera or a four-band multi-spectral (MS) camera. We use the Pan camera to benefit from its higher sensitivity and the colour or MS camera to benefit from its spectral properties. The resulting images are then compared to the ones acquired by a high resolution single Bayer-pattern colour camera (here referred to as HRC). We assessed the quality of the output images by performing image classification tests. The outputs prove that the proposed sensor fusion configurations can achieve higher accuracies compared to the images of the single Bayer-pattern colour camera. Therefore, incorporating a Pan camera on-board in the UAV missions and performing image fusion can help achieving higher quality images and accordingly higher accuracy classification results.

THE DARK ENERGY CAMERA

DOE Office of Scientific and Technical Information (OSTI.GOV)

Flaugher, B.; Diehl, H. T.; Alvarez, O.

2015-11-15

The Dark Energy Camera is a new imager with a 2.°2 diameter field of view mounted at the prime focus of the Victor M. Blanco 4 m telescope on Cerro Tololo near La Serena, Chile. The camera was designed and constructed by the Dark Energy Survey Collaboration and meets or exceeds the stringent requirements designed for the wide-field and supernova surveys for which the collaboration uses it. The camera consists of a five-element optical corrector, seven filters, a shutter with a 60 cm aperture, and a charge-coupled device (CCD) focal plane of 250 μm thick fully depleted CCDs cooled inside a vacuummore » Dewar. The 570 megapixel focal plane comprises 62 2k × 4k CCDs for imaging and 12 2k × 2k CCDs for guiding and focus. The CCDs have 15 μm × 15 μm pixels with a plate scale of 0.″263 pixel{sup −1}. A hexapod system provides state-of-the-art focus and alignment capability. The camera is read out in 20 s with 6–9 electron readout noise. This paper provides a technical description of the camera's engineering, construction, installation, and current status.« less

Technical and instrumental prerequisites for single-port laparoscopic solo surgery: State of art

PubMed Central

Kim, Say-June; Lee, Sang Chul

2015-01-01

With the aid of advanced surgical techniques and instruments, single-port laparoscopic surgery (SPLS) can be accomplished with just two surgical members: an operator and a camera assistant. Under these circumstances, the reasonable replacement of a human camera assistant by a mechanical camera holder has resulted in a new surgical procedure termed single-port solo surgery (SPSS). In SPSS, the fixation and coordinated movement of a camera held by mechanical devices provides fixed and stable operative images that are under the control of the operator. Therefore, SPSS primarily benefits from the provision of the operator’s eye-to-hand coordination. Because SPSS is an intuitive modification of SPLS, the indications for SPSS are the same as those for SPLS. Though SPSS necessitates more actions than the surgery with a human assistant, these difficulties seem to be easily overcome by the greater provision of static operative images and the need for less lens cleaning and repositioning of the camera. When the operation is expected to be difficult and demanding, the SPSS process could be assisted by the addition of another instrument holder besides the camera holder. PMID:25914453

The Dark Energy Camera

DOE PAGES

Flaugher, B.

2015-04-11

The Dark Energy Camera is a new imager with a 2.2-degree diameter field of view mounted at the prime focus of the Victor M. Blanco 4-meter telescope on Cerro Tololo near La Serena, Chile. The camera was designed and constructed by the Dark Energy Survey Collaboration, and meets or exceeds the stringent requirements designed for the wide-field and supernova surveys for which the collaboration uses it. The camera consists of a five element optical corrector, seven filters, a shutter with a 60 cm aperture, and a CCD focal plane of 250-μm thick fully depleted CCDs cooled inside a vacuum Dewar.more » The 570 Mpixel focal plane comprises 62 2k x 4k CCDs for imaging and 12 2k x 2k CCDs for guiding and focus. The CCDs have 15μm x 15μm pixels with a plate scale of 0.263" per pixel. A hexapod system provides state-of-the-art focus and alignment capability. The camera is read out in 20 seconds with 6-9 electrons readout noise. This paper provides a technical description of the camera's engineering, construction, installation, and current status.« less

Measurement of cosmic-ray muons with the Distributed Electronic Cosmic-ray Observatory, a network of smartphones

NASA Astrophysics Data System (ADS)

Vandenbroucke, J.; BenZvi, S.; Bravo, S.; Jensen, K.; Karn, P.; Meehan, M.; Peacock, J.; Plewa, M.; Ruggles, T.; Santander, M.; Schultz, D.; Simons, A. L.; Tosi, D.

2016-04-01

Solid-state camera image sensors can be used to detect ionizing radiation in addition to optical photons. We describe the Distributed Electronic Cosmic-ray Observatory (DECO), an app and associated public database that enables a network of consumer devices to detect cosmic rays and other ionizing radiation. In addition to terrestrial background radiation, cosmic-ray muon candidate events are detected as long, straight tracks passing through multiple pixels. The distribution of track lengths can be related to the thickness of the active (depleted) region of the camera image sensor through the known angular distribution of muons at sea level. We use a sample of candidate muon events detected by DECO to measure the thickness of the depletion region of the camera image sensor in a particular consumer smartphone model, the HTC Wildfire S. The track length distribution is fit better by a cosmic-ray muon angular distribution than an isotropic distribution, demonstrating that DECO can detect and identify cosmic-ray muons despite a background of other particle detections. Using the cosmic-ray distribution, we measure the depletion thickness to be 26.3 ± 1.4 μm. With additional data, the same method can be applied to additional models of image sensor. Once measured, the thickness can be used to convert track length to incident polar angle on a per-event basis. Combined with a determination of the incident azimuthal angle directly from the track orientation in the sensor plane, this enables direction reconstruction of individual cosmic-ray events using a single consumer device. The results simultaneously validate the use of cell phone camera image sensors as cosmic-ray muon detectors and provide a measurement of a parameter of camera image sensor performance which is not otherwise publicly available.

Gender Recognition from Human-Body Images Using Visible-Light and Thermal Camera Videos Based on a Convolutional Neural Network for Image Feature Extraction

PubMed Central

Nguyen, Dat Tien; Kim, Ki Wan; Hong, Hyung Gil; Koo, Ja Hyung; Kim, Min Cheol; Park, Kang Ryoung

2017-01-01

Extracting powerful image features plays an important role in computer vision systems. Many methods have previously been proposed to extract image features for various computer vision applications, such as the scale-invariant feature transform (SIFT), speed-up robust feature (SURF), local binary patterns (LBP), histogram of oriented gradients (HOG), and weighted HOG. Recently, the convolutional neural network (CNN) method for image feature extraction and classification in computer vision has been used in various applications. In this research, we propose a new gender recognition method for recognizing males and females in observation scenes of surveillance systems based on feature extraction from visible-light and thermal camera videos through CNN. Experimental results confirm the superiority of our proposed method over state-of-the-art recognition methods for the gender recognition problem using human body images. PMID:28335510

Gender Recognition from Human-Body Images Using Visible-Light and Thermal Camera Videos Based on a Convolutional Neural Network for Image Feature Extraction.

PubMed

Nguyen, Dat Tien; Kim, Ki Wan; Hong, Hyung Gil; Koo, Ja Hyung; Kim, Min Cheol; Park, Kang Ryoung

2017-03-20

Extracting powerful image features plays an important role in computer vision systems. Many methods have previously been proposed to extract image features for various computer vision applications, such as the scale-invariant feature transform (SIFT), speed-up robust feature (SURF), local binary patterns (LBP), histogram of oriented gradients (HOG), and weighted HOG. Recently, the convolutional neural network (CNN) method for image feature extraction and classification in computer vision has been used in various applications. In this research, we propose a new gender recognition method for recognizing males and females in observation scenes of surveillance systems based on feature extraction from visible-light and thermal camera videos through CNN. Experimental results confirm the superiority of our proposed method over state-of-the-art recognition methods for the gender recognition problem using human body images.

3D surface reconstruction for laparoscopic computer-assisted interventions: comparison of state-of-the-art methods

NASA Astrophysics Data System (ADS)

Groch, A.; Seitel, A.; Hempel, S.; Speidel, S.; Engelbrecht, R.; Penne, J.; Höller, K.; Röhl, S.; Yung, K.; Bodenstedt, S.; Pflaum, F.; dos Santos, T. R.; Mersmann, S.; Meinzer, H.-P.; Hornegger, J.; Maier-Hein, L.

2011-03-01

One of the main challenges related to computer-assisted laparoscopic surgery is the accurate registration of pre-operative planning images with patient's anatomy. One popular approach for achieving this involves intraoperative 3D reconstruction of the target organ's surface with methods based on multiple view geometry. The latter, however, require robust and fast algorithms for establishing correspondences between multiple images of the same scene. Recently, the first endoscope based on Time-of-Flight (ToF) camera technique was introduced. It generates dense range images with high update rates by continuously measuring the run-time of intensity modulated light. While this approach yielded promising results in initial experiments, the endoscopic ToF camera has not yet been evaluated in the context of related work. The aim of this paper was therefore to compare its performance with different state-of-the-art surface reconstruction methods on identical objects. For this purpose, surface data from a set of porcine organs as well as organ phantoms was acquired with four different cameras: a novel Time-of-Flight (ToF) endoscope, a standard ToF camera, a stereoscope, and a High Definition Television (HDTV) endoscope. The resulting reconstructed partial organ surfaces were then compared to corresponding ground truth shapes extracted from computed tomography (CT) data using a set of local and global distance metrics. The evaluation suggests that the ToF technique has high potential as means for intraoperative endoscopic surface registration.

Digital imaging with solid state x-ray image intensifiers

NASA Astrophysics Data System (ADS)

Damento, Michael A.; Radspinner, Rachel; Roehrig, Hans

1999-10-01

X-ray cameras in which a CCD is lens coupled to a large phosphor screen are known to suffer from a loss of x-ray signal due to poor light collection from conventional phosphors, making them unsuitable for most medical imaging applications. By replacing the standard phosphor with a solid-state image intensifier, it may be possible to improve the signal-to-noise ratio of the images produced with these cameras. The solid-state x-ray image intensifier is a multi- layer device in which a photoconductor layer controls the light output from an electroluminescent phosphor layer. While prototype devices have been used for direct viewing and video imaging, they are only now being evaluated in a digital imaging system. In the present work, the preparation and evaluation of intensifiers with a 65 mm square format are described. The intensifiers are prepared by screen- printing or doctor blading the following layers onto an ITO coated glass substrate: ZnS phosphor, opaque layer, CdS photoconductor, and carbon conductor. The total thickness of the layers is approximately 350 micrometers , 350 VAC at 400 Hz is applied to the device for operation. For a given x-ray dose, the intensifiers produce up to three times the intensity (after background subtracting) of Lanex Fast Front screens. X-ray images produced with the present intensifiers are somewhat noisy and their resolution is about half that of Lanex screens. Modifications are suggested which could improve the resolution and noise of the intensifiers.

OCAMS: The OSIRIS-REx Camera Suite

NASA Astrophysics Data System (ADS)

Rizk, B.; Drouet d'Aubigny, C.; Golish, D.; Fellows, C.; Merrill, C.; Smith, P.; Walker, M. S.; Hendershot, J. E.; Hancock, J.; Bailey, S. H.; DellaGiustina, D. N.; Lauretta, D. S.; Tanner, R.; Williams, M.; Harshman, K.; Fitzgibbon, M.; Verts, W.; Chen, J.; Connors, T.; Hamara, D.; Dowd, A.; Lowman, A.; Dubin, M.; Burt, R.; Whiteley, M.; Watson, M.; McMahon, T.; Ward, M.; Booher, D.; Read, M.; Williams, B.; Hunten, M.; Little, E.; Saltzman, T.; Alfred, D.; O'Dougherty, S.; Walthall, M.; Kenagy, K.; Peterson, S.; Crowther, B.; Perry, M. L.; See, C.; Selznick, S.; Sauve, C.; Beiser, M.; Black, W.; Pfisterer, R. N.; Lancaster, A.; Oliver, S.; Oquest, C.; Crowley, D.; Morgan, C.; Castle, C.; Dominguez, R.; Sullivan, M.

2018-02-01

The OSIRIS-REx Camera Suite (OCAMS) will acquire images essential to collecting a sample from the surface of Bennu. During proximity operations, these images will document the presence of satellites and plumes, record spin state, enable an accurate model of the asteroid's shape, and identify any surface hazards. They will confirm the presence of sampleable regolith on the surface, observe the sampling event itself, and image the sample head in order to verify its readiness to be stowed. They will document Bennu's history as an example of early solar system material, as a microgravity body with a planetesimal size-scale, and as a carbonaceous object. OCAMS is fitted with three cameras. The MapCam will record color images of Bennu as a point source on approach to the asteroid in order to connect Bennu's ground-based point-source observational record to later higher-resolution surface spectral imaging. The SamCam will document the sample site before, during, and after it is disturbed by the sample mechanism. The PolyCam, using its focus mechanism, will observe the sample site at sub-centimeter resolutions, revealing surface texture and morphology. While their imaging requirements divide naturally between the three cameras, they preserve a strong degree of functional overlap. OCAMS and the other spacecraft instruments will allow the OSIRIS-REx mission to collect a sample from a microgravity body on the same visit during which it was first optically acquired from long range, a useful capability as humanity reaches out to explore near-Earth, Main-Belt and Jupiter Trojan asteroids.

Image Sensors Enhance Camera Technologies

NASA Technical Reports Server (NTRS)

2010-01-01

In the 1990s, a Jet Propulsion Laboratory team led by Eric Fossum researched ways of improving complementary metal-oxide semiconductor (CMOS) image sensors in order to miniaturize cameras on spacecraft while maintaining scientific image quality. Fossum s team founded a company to commercialize the resulting CMOS active pixel sensor. Now called the Aptina Imaging Corporation, based in San Jose, California, the company has shipped over 1 billion sensors for use in applications such as digital cameras, camera phones, Web cameras, and automotive cameras. Today, one of every three cell phone cameras on the planet feature Aptina s sensor technology.

A comparison of select image-compression algorithms for an electronic still camera

NASA Technical Reports Server (NTRS)

Nerheim, Rosalee

1989-01-01

This effort is a study of image-compression algorithms for an electronic still camera. An electronic still camera can record and transmit high-quality images without the use of film, because images are stored digitally in computer memory. However, high-resolution images contain an enormous amount of information, and will strain the camera's data-storage system. Image compression will allow more images to be stored in the camera's memory. For the electronic still camera, a compression algorithm that produces a reconstructed image of high fidelity is most important. Efficiency of the algorithm is the second priority. High fidelity and efficiency are more important than a high compression ratio. Several algorithms were chosen for this study and judged on fidelity, efficiency and compression ratio. The transform method appears to be the best choice. At present, the method is compressing images to a ratio of 5.3:1 and producing high-fidelity reconstructed images.

Advanced Digital Forensic and Steganalysis Methods

DTIC Science & Technology

2009-02-01

investigation is simultaneously cropped, scaled, and processed, extending the technology when the digital image is printed, developing technology capable ...or other common processing operations). TECNOLOGY APPLICATIONS 1. Determining the origin of digital images 2. Matching an image to a camera...Technology Transfer and Innovation Partnerships Division of Research P.O. Box 6000 State University of New York Binghamton, NY 13902-6000 Phone: 607-777

Capturing method for integral three-dimensional imaging using multiviewpoint robotic cameras

NASA Astrophysics Data System (ADS)

Ikeya, Kensuke; Arai, Jun; Mishina, Tomoyuki; Yamaguchi, Masahiro

2018-03-01

Integral three-dimensional (3-D) technology for next-generation 3-D television must be able to capture dynamic moving subjects with pan, tilt, and zoom camerawork as good as in current TV program production. We propose a capturing method for integral 3-D imaging using multiviewpoint robotic cameras. The cameras are controlled through a cooperative synchronous system composed of a master camera controlled by a camera operator and other reference cameras that are utilized for 3-D reconstruction. When the operator captures a subject using the master camera, the region reproduced by the integral 3-D display is regulated in real space according to the subject's position and view angle of the master camera. Using the cooperative control function, the reference cameras can capture images at the narrowest view angle that does not lose any part of the object region, thereby maximizing the resolution of the image. 3-D models are reconstructed by estimating the depth from complementary multiviewpoint images captured by robotic cameras arranged in a two-dimensional array. The model is converted into elemental images to generate the integral 3-D images. In experiments, we reconstructed integral 3-D images of karate players and confirmed that the proposed method satisfied the above requirements.

An Acoustic Charge Transport Imager for High Definition Television

NASA Technical Reports Server (NTRS)

Hunt, William D.; Brennan, Kevin; May, Gary; Glenn, William E.; Richardson, Mike; Solomon, Richard

1999-01-01

This project, over its term, included funding to a variety of companies and organizations. In addition to Georgia Tech these included Florida Atlantic University with Dr. William E. Glenn as the P.I., Kodak with Mr. Mike Richardson as the P.I. and M.I.T./Polaroid with Dr. Richard Solomon as the P.I. The focus of the work conducted by these organizations was the development of camera hardware for High Definition Television (HDTV). The focus of the research at Georgia Tech was the development of new semiconductor technology to achieve a next generation solid state imager chip that would operate at a high frame rate (I 70 frames per second), operate at low light levels (via the use of avalanche photodiodes as the detector element) and contain 2 million pixels. The actual cost required to create this new semiconductor technology was probably at least 5 or 6 times the investment made under this program and hence we fell short of achieving this rather grand goal. We did, however, produce a number of spin-off technologies as a result of our efforts. These include, among others, improved avalanche photodiode structures, significant advancement of the state of understanding of ZnO/GaAs structures and significant contributions to the analysis of general GaAs semiconductor devices and the design of Surface Acoustic Wave resonator filters for wireless communication. More of these will be described in the report. The work conducted at the partner sites resulted in the development of 4 prototype HDTV cameras. The HDTV camera developed by Kodak uses the Kodak KAI-2091M high- definition monochrome image sensor. This progressively-scanned charge-coupled device (CCD) can operate at video frame rates and has 9 gm square pixels. The photosensitive area has a 16:9 aspect ratio and is consistent with the "Common Image Format" (CIF). It features an active image area of 1928 horizontal by 1084 vertical pixels and has a 55% fill factor. The camera is designed to operate in continuous mode with an output data rate of 5MHz, which gives a maximum frame rate of 4 frames per second. The MIT/Polaroid group developed two cameras under this program. The cameras have effectively four times the current video spatial resolution and at 60 frames per second are double the normal video frame rate.

Film cameras or digital sensors? The challenge ahead for aerial imaging

USGS Publications Warehouse

Light, D.L.

1996-01-01

Cartographic aerial cameras continue to play the key role in producing quality products for the aerial photography business, and specifically for the National Aerial Photography Program (NAPP). One NAPP photograph taken with cameras capable of 39 lp/mm system resolution can contain the equivalent of 432 million pixels at 11 ??m spot size, and the cost is less than $75 per photograph to scan and output the pixels on a magnetic storage medium. On the digital side, solid state charge coupled device linear and area arrays can yield quality resolution (7 to 12 ??m detector size) and a broader dynamic range. If linear arrays are to compete with film cameras, they will require precise attitude and positioning of the aircraft so that the lines of pixels can be unscrambled and put into a suitable homogeneous scene that is acceptable to an interpreter. Area arrays need to be much larger than currently available to image scenes competitive in size with film cameras. Analysis of the relative advantages and disadvantages of the two systems show that the analog approach is more economical at present. However, as arrays become larger, attitude sensors become more refined, global positioning system coordinate readouts become commonplace, and storage capacity becomes more affordable, the digital camera may emerge as the imaging system for the future. Several technical challenges must be overcome if digital sensors are to advance to where they can support mapping, charting, and geographic information system applications.

Camera Trajectory fromWide Baseline Images

NASA Astrophysics Data System (ADS)

Havlena, M.; Torii, A.; Pajdla, T.

2008-09-01

Camera trajectory estimation, which is closely related to the structure from motion computation, is one of the fundamental tasks in computer vision. Reliable camera trajectory estimation plays an important role in 3D reconstruction, self localization, and object recognition. There are essential issues for a reliable camera trajectory estimation, for instance, choice of the camera and its geometric projection model, camera calibration, image feature detection and description, and robust 3D structure computation. Most of approaches rely on classical perspective cameras because of the simplicity of their projection models and ease of their calibration. However, classical perspective cameras offer only a limited field of view, and thus occlusions and sharp camera turns may cause that consecutive frames look completely different when the baseline becomes longer. This makes the image feature matching very difficult (or impossible) and the camera trajectory estimation fails under such conditions. These problems can be avoided if omnidirectional cameras, e.g. a fish-eye lens convertor, are used. The hardware which we are using in practice is a combination of Nikon FC-E9 mounted via a mechanical adaptor onto a Kyocera Finecam M410R digital camera. Nikon FC-E9 is a megapixel omnidirectional addon convertor with 180° view angle which provides images of photographic quality. Kyocera Finecam M410R delivers 2272×1704 images at 3 frames per second. The resulting combination yields a circular view of diameter 1600 pixels in the image. Since consecutive frames of the omnidirectional camera often share a common region in 3D space, the image feature matching is often feasible. On the other hand, the calibration of these cameras is non-trivial and is crucial for the accuracy of the resulting 3D reconstruction. We calibrate omnidirectional cameras off-line using the state-of-the-art technique and Mičušík's two-parameter model, that links the radius of the image point r to the angle θ of its corresponding rays w.r.t. the optical axis as θ = ar 1+br2 . After a successful calibration, we know the correspondence of the image points to the 3D optical rays in the coordinate system of the camera. The following steps aim at finding the transformation between the camera and the world coordinate systems, i.e. the pose of the camera in the 3D world, using 2D image matches. For computing 3D structure, we construct a set of tentative matches detecting different affine covariant feature regions including MSER, Harris Affine, and Hessian Affine in acquired images. These features are alternative to popular SIFT features and work comparably in our situation. Parameters of the detectors are chosen to limit the number of regions to 1-2 thousands per image. The detected regions are assigned local affine frames (LAF) and transformed into standard positions w.r.t. their LAFs. Discrete Cosine Descriptors are computed for each region in the standard position. Finally, mutual distances of all regions in one image and all regions in the other image are computed as the Euclidean distances of their descriptors and tentative matches are constructed by selecting the mutually closest pairs. Opposed to the methods using short baseline images, simpler image features which are not affine covariant cannot be used because the view point can change a lot between consecutive frames. Furthermore, feature matching has to be performed on the whole frame because no assumptions on the proximity of the consecutive projections can be made for wide baseline images. This is making the feature detection, description, and matching much more time-consuming than it is for short baseline images and limits the usage to low frame rate sequences when operating in real-time. Robust 3D structure can be computed by RANSAC which searches for the largest subset of the set of tentative matches which is, within a predefined threshold ", consistent with an epipolar geometry. We use ordered sampling as suggested in to draw 5-tuples from the list of tentative matches ordered ascendingly by the distance of their descriptors which may help to reduce the number of samples in RANSAC. From each 5-tuple, relative orientation is computed by solving the 5-point minimal relative orientation problem for calibrated cameras. Often, there are more models which are supported by a large number of matches. Thus the chance that the correct model, even if it has the largest support, will be found by running a single RANSAC is small. Work suggested to generate models by randomized sampling as in RANSAC but to use soft (kernel) voting for a parameter instead of looking for the maximal support. The best model is then selected as the one with the parameter closest to the maximum in the accumulator space. In our case, we vote in a two-dimensional accumulator for the estimated camera motion direction. However, unlike in, we do not cast votes directly by each sampled epipolar geometry but by the best epipolar geometries recovered by ordered sampling of RANSAC. With our technique, we could go up to the 98.5 % contamination of mismatches with comparable effort as simple RANSAC does for the contamination by 84 %. The relative camera orientation with the motion direction closest to the maximum in the voting space is finally selected. As already mentioned in the first paragraph, the use of camera trajectory estimates is quite wide. In we have introduced a technique for measuring the size of camera translation relatively to the observed scene which uses the dominant apical angle computed at the reconstructed scene points and is robust against mismatches. The experiments demonstrated that the measure can be used to improve the robustness of camera path computation and object recognition for methods which use a geometric, e.g. the ground plane, constraint such as does for the detection of pedestrians. Using the camera trajectories, perspective cutouts with stabilized horizon are constructed and an arbitrary object recognition routine designed to work with images acquired by perspective cameras can be used without any further modifications.

[Intraoperative augmented reality visualization. Current state of development and initial experiences with the CamC].

PubMed

Weidert, S; Wang, L; von der Heide, A; Navab, N; Euler, E

2012-03-01

The intraoperative application of augmented reality (AR) has so far mainly taken place in the field of endoscopy. Here, the camera image of the endoscope was augmented by computer graphics derived mostly from preoperative imaging. Due to the complex setup and operation of the devices, they have not yet become part of routine clinical practice. The Camera Augmented Mobile C-arm (CamC) that extends a classic C-arm by a video camera and mirror construction is characterized by its uncomplicated handling. It combines its video live stream geometrically correct with the acquired X-ray. The clinical application of the device in 43 cases showed the strengths of the device in positioning for X-ray acquisition, incision placement, K-wire placement, and instrument guidance. With its new function and the easy integration into the OR workflow of any procedure that requires X-ray imaging, the CamC has the potential to become the first widely used AR technology for orthopedic and trauma surgery.

Gigavision - A weatherproof, multibillion pixel resolution time-lapse camera system for recording and tracking phenology in every plant in a landscape

NASA Astrophysics Data System (ADS)

Brown, T.; Borevitz, J. O.; Zimmermann, C.

2010-12-01

We have a developed a camera system that can record hourly, gigapixel (multi-billion pixel) scale images of an ecosystem in a 360x90 degree panorama. The “Gigavision” camera system is solar-powered and can wirelessly stream data to a server. Quantitative data collection from multiyear timelapse gigapixel images is facilitated through an innovative web-based toolkit for recording time-series data on developmental stages (phenology) from any plant in the camera’s field of view. Gigapixel images enable time-series recording of entire landscapes with a resolution sufficient to record phenology from a majority of individuals in entire populations of plants. When coupled with next generation sequencing, quantitative population genomics can be performed in a landscape context linking ecology and evolution in situ and in real time. The Gigavision camera system achieves gigapixel image resolution by recording rows and columns of overlapping megapixel images. These images are stitched together into a single gigapixel resolution image using commercially available panorama software. Hardware consists of a 5-18 megapixel resolution DSLR or Network IP camera mounted on a pair of heavy-duty servo motors that provide pan-tilt capabilities. The servos and camera are controlled with a low-power Windows PC. Servo movement, power switching, and system status monitoring are enabled with Phidgets-brand sensor boards. System temperature, humidity, power usage, and battery voltage are all monitored at 5 minute intervals. All sensor data is uploaded via cellular or 802.11 wireless to an interactive online interface for easy remote monitoring of system status. Systems with direct internet connections upload the full sized images directly to our automated stitching server where they are stitched and available online for viewing within an hour of capture. Systems with cellular wireless upload an 80 megapixel “thumbnail” of each larger panorama and full-sized images are manually retrieved at bi-weekly intervals. Our longer-term goal is to make gigapixel time-lapse datasets available online in an interactive interface that layers plant-level phenology data with gigapixel resolution images, genomic sequence data from individual plants with weather and other abitotic sensor data. Co-visualization of all of these data types provides researchers with a powerful new tool for examining complex ecological interactions across scales from the individual to the ecosystem. We will present detailed phenostage data from more than 100 plants of multiple species from our Gigavision timelapse camera at our “Big Blowout East” field site in the Indiana Dunes State Park, IN. This camera has been recording three to four 700 million pixel images a day since February 28, 2010. The camera field of view covers an area of about 7 hectares resulting in an average image resolution of about 1 pixel per centimeter over the entire site. We will also discuss some of the many technological challenges with developing and maintaining these types of hardware systems, collecting quantitative data from gigapixel resolution time-lapse data and effectively managing terabyte-sized datasets of millions of images.

Temporal Coding of Volumetric Imagery

NASA Astrophysics Data System (ADS)

Llull, Patrick Ryan

'Image volumes' refer to realizations of images in other dimensions such as time, spectrum, and focus. Recent advances in scientific, medical, and consumer applications demand improvements in image volume capture. Though image volume acquisition continues to advance, it maintains the same sampling mechanisms that have been used for decades; every voxel must be scanned and is presumed independent of its neighbors. Under these conditions, improving performance comes at the cost of increased system complexity, data rates, and power consumption. This dissertation explores systems and methods capable of efficiently improving sensitivity and performance for image volume cameras, and specifically proposes several sampling strategies that utilize temporal coding to improve imaging system performance and enhance our awareness for a variety of dynamic applications. Video cameras and camcorders sample the video volume (x,y,t) at fixed intervals to gain understanding of the volume's temporal evolution. Conventionally, one must reduce the spatial resolution to increase the framerate of such cameras. Using temporal coding via physical translation of an optical element known as a coded aperture, the compressive temporal imaging (CACTI) camera emonstrates a method which which to embed the temporal dimension of the video volume into spatial (x,y) measurements, thereby greatly improving temporal resolution with minimal loss of spatial resolution. This technique, which is among a family of compressive sampling strategies developed at Duke University, temporally codes the exposure readout functions at the pixel level. Since video cameras nominally integrate the remaining image volume dimensions (e.g. spectrum and focus) at capture time, spectral (x,y,t,lambda) and focal (x,y,t,z) image volumes are traditionally captured via sequential changes to the spectral and focal state of the system, respectively. The CACTI camera's ability to embed video volumes into images leads to exploration of other information within that video; namely, focal and spectral information. The next part of the thesis demonstrates derivative works of CACTI: compressive extended depth of field and compressive spectral-temporal imaging. These works successfully show the technique's extension of temporal coding to improve sensing performance in these other dimensions. Geometrical optics-related tradeoffs, such as the classic challenges of wide-field-of-view and high resolution photography, have motivated the development of mulitscale camera arrays. The advent of such designs less than a decade ago heralds a new era of research- and engineering-related challenges. One significant challenge is that of managing the focal volume (x,y,z ) over wide fields of view and resolutions. The fourth chapter shows advances on focus and image quality assessment for a class of multiscale gigapixel cameras developed at Duke. Along the same line of work, we have explored methods for dynamic and adaptive addressing of focus via point spread function engineering. We demonstrate another form of temporal coding in the form of physical translation of the image plane from its nominal focal position. We demonstrate this technique's capability to generate arbitrary point spread functions.

Optimal reproducibility of gated sestamibi and thallium myocardial perfusion study left ventricular ejection fractions obtained on a solid-state CZT cardiac camera requires operator input.

PubMed

Cherk, Martin H; Ky, Jason; Yap, Kenneth S K; Campbell, Patrina; McGrath, Catherine; Bailey, Michael; Kalff, Victor

2012-08-01

To evaluate the reproducibility of serial re-acquisitions of gated Tl-201 and Tc-99m sestamibi left ventricular ejection fraction (LVEF) measurements obtained on a new generation solid-state cardiac camera system during myocardial perfusion imaging and the importance of manual operator optimization of left ventricular wall tracking. Resting blinded automated (auto) and manual operator optimized (opt) LVEF measurements were measured using ECT toolbox (ECT) and Cedars-Sinai QGS software in two separate cohorts of 55 Tc-99m sestamibi (MIBI) and 50 thallium (Tl-201) myocardial perfusion studies (MPS) acquired in both supine and prone positions on a cadmium zinc telluride (CZT) solid-state camera system. Resting supine and prone automated LVEF measurements were similarly obtained in a further separate cohort of 52 gated cardiac blood pool scans (GCBPS) for validation of methodology and comparison. Appropriate use of Bland-Altman, chi-squared and Levene's equality of variance tests was used to analyse the resultant data comparisons. For all radiotracer and software combinations, manual checking and optimization of valve planes (+/- centre radius with ECT software) resulted in significant improvement in MPS LVEF reproducibility that approached that of planar GCBPS. No difference was demonstrated between optimized MIBI/Tl-201 QGS and planar GCBPS LVEF reproducibility (P = .17 and P = .48, respectively). ECT required significantly more manual optimization compared to QGS software in both supine and prone positions independent of radiotracer used (P < .02). Reproducibility of gated sestamibi and Tl-201 LVEF measurements obtained during myocardial perfusion imaging with ECT toolbox or QGS software packages using a new generation solid-state cardiac camera with improved image quality approaches that of planar GCBPS however requires visual quality control and operator optimization of left ventricular wall tracking for best results. Using this superior cardiac technology, Tl-201 reproducibility also appears at least equivalent to sestamibi for measuring LVEF.

Image Mosaicking Approach for a Double-Camera System in the GaoFen2 Optical Remote Sensing Satellite Based on the Big Virtual Camera.

PubMed

Cheng, Yufeng; Jin, Shuying; Wang, Mi; Zhu, Ying; Dong, Zhipeng

2017-06-20

The linear array push broom imaging mode is widely used for high resolution optical satellites (HROS). Using double-cameras attached by a high-rigidity support along with push broom imaging is one method to enlarge the field of view while ensuring high resolution. High accuracy image mosaicking is the key factor of the geometrical quality of complete stitched satellite imagery. This paper proposes a high accuracy image mosaicking approach based on the big virtual camera (BVC) in the double-camera system on the GaoFen2 optical remote sensing satellite (GF2). A big virtual camera can be built according to the rigorous imaging model of a single camera; then, each single image strip obtained by each TDI-CCD detector can be re-projected to the virtual detector of the big virtual camera coordinate system using forward-projection and backward-projection to obtain the corresponding single virtual image. After an on-orbit calibration and relative orientation, the complete final virtual image can be obtained by stitching the single virtual images together based on their coordinate information on the big virtual detector image plane. The paper subtly uses the concept of the big virtual camera to obtain a stitched image and the corresponding high accuracy rational function model (RFM) for concurrent post processing. Experiments verified that the proposed method can achieve seamless mosaicking while maintaining the geometric accuracy.

Methods for identification of images acquired with digital cameras

NASA Astrophysics Data System (ADS)

Geradts, Zeno J.; Bijhold, Jurrien; Kieft, Martijn; Kurosawa, Kenji; Kuroki, Kenro; Saitoh, Naoki

2001-02-01

From the court we were asked whether it is possible to determine if an image has been made with a specific digital camera. This question has to be answered in child pornography cases, where evidence is needed that a certain picture has been made with a specific camera. We have looked into different methods of examining the cameras to determine if a specific image has been made with a camera: defects in CCDs, file formats that are used, noise introduced by the pixel arrays and watermarking in images used by the camera manufacturer.

Aircraft engine-mounted camera system for long wavelength infrared imaging of in-service thermal barrier coated turbine blades

NASA Astrophysics Data System (ADS)

Markham, James; Cosgrove, Joseph; Scire, James; Haldeman, Charles; Agoos, Ian

2014-12-01

This paper announces the implementation of a long wavelength infrared camera to obtain high-speed thermal images of an aircraft engine's in-service thermal barrier coated turbine blades. Long wavelength thermal images were captured of first-stage blades. The achieved temporal and spatial resolutions allowed for the identification of cooling-hole locations. The software and synchronization components of the system allowed for the selection of any blade on the turbine wheel, with tuning capability to image from leading edge to trailing edge. Its first application delivered calibrated thermal images as a function of turbine rotational speed at both steady state conditions and during engine transients. In advance of presenting these data for the purpose of understanding engine operation, this paper focuses on the components of the system, verification of high-speed synchronized operation, and the integration of the system with the commercial jet engine test bed.

Aircraft engine-mounted camera system for long wavelength infrared imaging of in-service thermal barrier coated turbine blades.

PubMed

Markham, James; Cosgrove, Joseph; Scire, James; Haldeman, Charles; Agoos, Ian

2014-12-01

This paper announces the implementation of a long wavelength infrared camera to obtain high-speed thermal images of an aircraft engine's in-service thermal barrier coated turbine blades. Long wavelength thermal images were captured of first-stage blades. The achieved temporal and spatial resolutions allowed for the identification of cooling-hole locations. The software and synchronization components of the system allowed for the selection of any blade on the turbine wheel, with tuning capability to image from leading edge to trailing edge. Its first application delivered calibrated thermal images as a function of turbine rotational speed at both steady state conditions and during engine transients. In advance of presenting these data for the purpose of understanding engine operation, this paper focuses on the components of the system, verification of high-speed synchronized operation, and the integration of the system with the commercial jet engine test bed.

Intrinsic melanin and hemoglobin colour components for skin lesion malignancy detection.

PubMed

Madooei, Ali; Drew, Mark S; Sadeghi, Maryam; Atkins, M Stella

2012-01-01

In this paper we propose a new log-chromaticity 2-D colour space, an extension of previous approaches, which succeeds in removing confounding factors from dermoscopic images: (i) the effects of the particular camera characteristics for the camera system used in forming RGB images; (ii) the colour of the light used in the dermoscope; (iii) shading induced by imaging non-flat skin surfaces; (iv) and light intensity, removing the effect of light-intensity falloff toward the edges of the dermoscopic image. In the context of a blind source separation of the underlying colour, we arrive at intrinsic melanin and hemoglobin images, whose properties are then used in supervised learning to achieve excellent malignant vs. benign skin lesion classification. In addition, we propose using the geometric-mean of colour for skin lesion segmentation based on simple grey-level thresholding, with results outperforming the state of the art.

Thermal Transfer Compared To The Fourteen Other Imaging Technologies

NASA Astrophysics Data System (ADS)

O'Leary, John W.

1989-07-01

A quiet revolution in the world of imaging has been underway for the past few years. The older technologies of dot matrix, daisy wheel, thermal paper and pen plotters have been increasingly displaced by laser, ink jet and thermal transfer. The net result of this revolution is improved technologies that afford superior imaging, quiet operation, plain paper usage, instant operation, and solid state components. Thermal transfer is one of the processes that incorporates these benefits. Among the imaging application for thermal transfer are: 1. Bar code labeling and scanning. 2. New systems for airline ticketing, boarding passes, reservations, etc. 3. Color computer graphics and imaging. 4. Copying machines that copy in color. 5. Fast growing communications media such as facsimile. 6. Low cost word processors and computer printers. 7. New devices that print pictures from video cameras or television sets. 8. Cameras utilizing computer chips in place of film.

CMOS image sensors: State-of-the-art

NASA Astrophysics Data System (ADS)

Theuwissen, Albert J. P.

2008-09-01

This paper gives an overview of the state-of-the-art of CMOS image sensors. The main focus is put on the shrinkage of the pixels : what is the effect on the performance characteristics of the imagers and on the various physical parameters of the camera ? How is the CMOS pixel architecture optimized to cope with the negative performance effects of the ever-shrinking pixel size ? On the other hand, the smaller dimensions in CMOS technology allow further integration on column level and even on pixel level. This will make CMOS imagers even smarter that they are already.

Advanced electro-optical imaging techniques. [conference papers on sensor technology applicable to Large Space Telescope program

NASA Technical Reports Server (NTRS)

Sobieski, S. (Editor); Wampler, E. J. (Editor)

1973-01-01

The papers presented at the symposium are given which deal with the present state of sensors, as may be applicable to the Large Space Telescope (LST) program. Several aspects of sensors are covered including a discussion of the properties of photocathodes and the operational imaging camera tubes.

Automatic calibration method for plenoptic camera

NASA Astrophysics Data System (ADS)

Luan, Yinsen; He, Xing; Xu, Bing; Yang, Ping; Tang, Guomao

2016-04-01

An automatic calibration method is proposed for a microlens-based plenoptic camera. First, all microlens images on the white image are searched and recognized automatically based on digital morphology. Then, the center points of microlens images are rearranged according to their relative position relationships. Consequently, the microlens images are located, i.e., the plenoptic camera is calibrated without the prior knowledge of camera parameters. Furthermore, this method is appropriate for all types of microlens-based plenoptic cameras, even the multifocus plenoptic camera, the plenoptic camera with arbitrarily arranged microlenses, or the plenoptic camera with different sizes of microlenses. Finally, we verify our method by the raw data of Lytro. The experiments show that our method has higher intelligence than the methods published before.

Micro-optical system based 3D imaging for full HD depth image capturing

NASA Astrophysics Data System (ADS)

Park, Yong-Hwa; Cho, Yong-Chul; You, Jang-Woo; Park, Chang-Young; Yoon, Heesun; Lee, Sang-Hun; Kwon, Jong-Oh; Lee, Seung-Wan

2012-03-01

20 Mega-Hertz-switching high speed image shutter device for 3D image capturing and its application to system prototype are presented. For 3D image capturing, the system utilizes Time-of-Flight (TOF) principle by means of 20MHz high-speed micro-optical image modulator, so called 'optical shutter'. The high speed image modulation is obtained using the electro-optic operation of the multi-layer stacked structure having diffractive mirrors and optical resonance cavity which maximizes the magnitude of optical modulation. The optical shutter device is specially designed and fabricated realizing low resistance-capacitance cell structures having small RC-time constant. The optical shutter is positioned in front of a standard high resolution CMOS image sensor and modulates the IR image reflected from the object to capture a depth image. Suggested novel optical shutter device enables capturing of a full HD depth image with depth accuracy of mm-scale, which is the largest depth image resolution among the-state-of-the-arts, which have been limited up to VGA. The 3D camera prototype realizes color/depth concurrent sensing optical architecture to capture 14Mp color and full HD depth images, simultaneously. The resulting high definition color/depth image and its capturing device have crucial impact on 3D business eco-system in IT industry especially as 3D image sensing means in the fields of 3D camera, gesture recognition, user interface, and 3D display. This paper presents MEMS-based optical shutter design, fabrication, characterization, 3D camera system prototype and image test results.

Comparison of image quality, myocardial perfusion, and LV function between standard imaging and single-injection ultra-low-dose imaging using a high-efficiency SPECT camera: the MILLISIEVERT study

PubMed Central

Einstein, Andrew J.; Blankstein, Ron; Andrews, Howard; Fish, Mathews; Padgett, Richard; Hayes, Sean W.; Friedman, John D.; Qureshi, Mehreen; Rakotoarivelo, Harivony; Slomka, Piotr; Nakazato, Ryo; Bokhari, Sabahat; Di Carli, Marcello; Berman, Daniel S.

2015-01-01

SPECT myocardial perfusion imaging (MPI) plays a central role in coronary artery disease diagnosis; but concerns exist regarding its radiation burden. Compared to standard Anger-SPECT (A-SPECT) cameras, new high-efficiency (HE) cameras with specialized collimators and solid-state cadmium-zinc-telluride detectors offer potential to maintain image quality (IQ), while reducing administered activity and thus radiation dose to patients. No previous study has compared IQ, interpretation, total perfusion deficit (TPD), or ejection fraction (EF) in patients receiving both ultra-low-dose (ULD) imaging on a HE-SPECT camera and standard low-dose (SLD) A-SPECT imaging. Methods We compared ULD-HE-SPECT to SLD-A-SPECT imaging by dividing the rest dose in 101 patients at 3 sites scheduled to undergo clinical A-SPECT MPI using a same day rest/stress Tc-99m protocol. Patients received HE-SPECT imaging following an initial ~130 MBq (3.5mCi) dose, and SLD-A-SPECT imaging following the remainder of the planned dose. Images were scored visually by 2 blinded readers for IQ and summed rest score (SRS). TPD and EF were assessed quantitatively. Results Mean activity was 134 MBq (3.62 mCi) for ULD-HE-SPECT (effective dose 1.15 mSv) and 278 MBq (7.50 mCi, 2.39 mSv) for SLD-A-SPECT. Overall IQ was superior for ULD-HE-SPECT (p<0.0001), with twice as many studies graded excellent quality. Extracardiac activity and overall perfusion assessment were similar. Between-method correlations were high for SRS (r=0.87), TPD (r=0.91), and EF (r=0.88). Conclusion ULD-HE-SPECT rest imaging correlates highly with SLD-A-SPECT. It has improved image quality, comparable extracardiac activity, and achieves radiation dose reduction to 1 mSv for a single injection. PMID:24982439

Development of plenoptic infrared camera using low dimensional material based photodetectors

NASA Astrophysics Data System (ADS)

Chen, Liangliang

Infrared (IR) sensor has extended imaging from submicron visible spectrum to tens of microns wavelength, which has been widely used for military and civilian application. The conventional bulk semiconductor materials based IR cameras suffer from low frame rate, low resolution, temperature dependent and highly cost, while the unusual Carbon Nanotube (CNT), low dimensional material based nanotechnology has been made much progress in research and industry. The unique properties of CNT lead to investigate CNT based IR photodetectors and imaging system, resolving the sensitivity, speed and cooling difficulties in state of the art IR imagings. The reliability and stability is critical to the transition from nano science to nano engineering especially for infrared sensing. It is not only for the fundamental understanding of CNT photoresponse induced processes, but also for the development of a novel infrared sensitive material with unique optical and electrical features. In the proposed research, the sandwich-structured sensor was fabricated within two polymer layers. The substrate polyimide provided sensor with isolation to background noise, and top parylene packing blocked humid environmental factors. At the same time, the fabrication process was optimized by real time electrical detection dielectrophoresis and multiple annealing to improve fabrication yield and sensor performance. The nanoscale infrared photodetector was characterized by digital microscopy and precise linear stage in order for fully understanding it. Besides, the low noise, high gain readout system was designed together with CNT photodetector to make the nano sensor IR camera available. To explore more of infrared light, we employ compressive sensing algorithm into light field sampling, 3-D camera and compressive video sensing. The redundant of whole light field, including angular images for light field, binocular images for 3-D camera and temporal information of video streams, are extracted and expressed in compressive approach. The following computational algorithms are applied to reconstruct images beyond 2D static information. The super resolution signal processing was then used to enhance and improve the image spatial resolution. The whole camera system brings a deeply detailed content for infrared spectrum sensing.

Digital camera with apparatus for authentication of images produced from an image file

NASA Technical Reports Server (NTRS)

Friedman, Gary L. (Inventor)

1993-01-01

A digital camera equipped with a processor for authentication of images produced from an image file taken by the digital camera is provided. The digital camera processor has embedded therein a private key unique to it, and the camera housing has a public key that is so uniquely based upon the private key that digital data encrypted with the private key by the processor may be decrypted using the public key. The digital camera processor comprises means for calculating a hash of the image file using a predetermined algorithm, and second means for encrypting the image hash with the private key, thereby producing a digital signature. The image file and the digital signature are stored in suitable recording means so they will be available together. Apparatus for authenticating at any time the image file as being free of any alteration uses the public key for decrypting the digital signature, thereby deriving a secure image hash identical to the image hash produced by the digital camera and used to produce the digital signature. The apparatus calculates from the image file an image hash using the same algorithm as before. By comparing this last image hash with the secure image hash, authenticity of the image file is determined if they match, since even one bit change in the image hash will cause the image hash to be totally different from the secure hash.

Plenoptic camera image simulation for reconstruction algorithm verification

NASA Astrophysics Data System (ADS)

Schwiegerling, Jim

2014-09-01

Plenoptic cameras have emerged in recent years as a technology for capturing light field data in a single snapshot. A conventional digital camera can be modified with the addition of a lenslet array to create a plenoptic camera. Two distinct camera forms have been proposed in the literature. The first has the camera image focused onto the lenslet array. The lenslet array is placed over the camera sensor such that each lenslet forms an image of the exit pupil onto the sensor. The second plenoptic form has the lenslet array relaying the image formed by the camera lens to the sensor. We have developed a raytracing package that can simulate images formed by a generalized version of the plenoptic camera. Several rays from each sensor pixel are traced backwards through the system to define a cone of rays emanating from the entrance pupil of the camera lens. Objects that lie within this cone are integrated to lead to a color and exposure level for that pixel. To speed processing three-dimensional objects are approximated as a series of planes at different depths. Repeating this process for each pixel in the sensor leads to a simulated plenoptic image on which different reconstruction algorithms can be tested.

QuadCam - A Quadruple Polarimetric Camera for Space Situational Awareness

NASA Astrophysics Data System (ADS)

Skuljan, J.

A specialised quadruple polarimetric camera for space situational awareness, QuadCam, has been built at the Defence Technology Agency (DTA), New Zealand, as part of collaboration with the Defence Science and Technology Laboratory (Dstl), United Kingdom. The design was based on a similar system originally developed at Dstl, with some significant modifications for improved performance. The system is made up of four identical CCD cameras looking in the same direction, but in a different plane of polarisation at 0, 45, 90 and 135 degrees with respect to the reference plane. A standard set of Stokes parameters can be derived from the four images in order to describe the state of polarisation of an object captured in the field of view. The modified design of the DTA QuadCam makes use of four small Raspberry Pi computers, so that each camera is controlled by its own computer in order to speed up the readout process and ensure that the four individual frames are taken simultaneously (to within 100-200 microseconds). In addition, a new firmware was requested from the camera manufacturer so that an output signal is generated to indicate the state of the camera shutter. A specialised GPS unit (also developed at DTA) is then used to monitor the shutter signals from the four cameras and record the actual time of exposure to an accuracy of about 100 microseconds. This makes the system well suited for the observation of fast-moving objects in the low Earth orbit (LEO). The QuadCam is currently mounted on a Paramount MEII robotic telescope mount at the newly built DTA space situational awareness observatory located on Whangaparaoa Peninsula near Auckland, New Zealand. The system will be used for tracking satellites in low Earth orbit and geostationary belt as well. The performance of the camera has been evaluated and a series of test images have been collected in order to derive the polarimetric signatures for selected satellites.

An Efficient Image Compressor for Charge Coupled Devices Camera

PubMed Central

Li, Jin; Xing, Fei; You, Zheng

2014-01-01

Recently, the discrete wavelet transforms- (DWT-) based compressor, such as JPEG2000 and CCSDS-IDC, is widely seen as the state of the art compression scheme for charge coupled devices (CCD) camera. However, CCD images project on the DWT basis to produce a large number of large amplitude high-frequency coefficients because these images have a large number of complex texture and contour information, which are disadvantage for the later coding. In this paper, we proposed a low-complexity posttransform coupled with compressing sensing (PT-CS) compression approach for remote sensing image. First, the DWT is applied to the remote sensing image. Then, a pair base posttransform is applied to the DWT coefficients. The pair base are DCT base and Hadamard base, which can be used on the high and low bit-rate, respectively. The best posttransform is selected by the l p-norm-based approach. The posttransform is considered as the sparse representation stage of CS. The posttransform coefficients are resampled by sensing measurement matrix. Experimental results on on-board CCD camera images show that the proposed approach significantly outperforms the CCSDS-IDC-based coder, and its performance is comparable to that of the JPEG2000 at low bit rate and it does not have the high excessive implementation complexity of JPEG2000. PMID:25114977

The DUV Stability of Superlattice-Doped CMOS Detector Arrays

NASA Technical Reports Server (NTRS)

Hoenk, M. E.; Carver, A. G.; Jones, T.; Dickie, M.; Cheng, P.; Greer, H. F.; Nikzad, S.; Sgro, J.; Tsur, S.

2013-01-01

JPL and Alacron have recently developed a high performance, DUV camera with a superlattice doped CMOS imaging detector. Supperlattice doped detectors achieve nearly 100% internal quantum efficiency in the deep and far ultraviolet, and a single layer, Al2O3 antireflection coating enables 64% external quantum efficiency at 263nm. In lifetime tests performed at Applied Materials using 263 nm pulsed, solid state and 193 nm pulsed excimer laser, the quantum efficiency and dark current of the JPL/Alacron camera remained stable to better than 1% precision during long-term exposure to several billion laser pulses, with no measurable degradation, no blooming and no image memory at 1000 fps.

78 FR 60248 - Order Denying Export Privileges

Federal Register 2010, 2011, 2012, 2013, 2014

2013-10-01

... DEPARTMENT OF COMMERCE Bureau of Industry and Security Order Denying Export Privileges In the... commit an offense against the United States, that is, to willfully export from the United States to Belarus export-controlled items, including but not limited to L-3 x200xp Handheld Thermal Imaging Cameras...

Ultrahigh sensitivity endoscopic camera using a new CMOS image sensor: providing with clear images under low illumination in addition to fluorescent images.

PubMed

Aoki, Hisae; Yamashita, Hiromasa; Mori, Toshiyuki; Fukuyo, Tsuneo; Chiba, Toshio

2014-11-01

We developed a new ultrahigh-sensitive CMOS camera using a specific sensor that has a wide range of spectral sensitivity characteristics. The objective of this study is to present our updated endoscopic technology that has successfully integrated two innovative functions; ultrasensitive imaging as well as advanced fluorescent viewing. Two different experiments were conducted. One was carried out to evaluate the function of the ultrahigh-sensitive camera. The other was to test the availability of the newly developed sensor and its performance as a fluorescence endoscope. In both studies, the distance from the endoscopic tip to the target was varied and those endoscopic images in each setting were taken for further comparison. In the first experiment, the 3-CCD camera failed to display the clear images under low illumination, and the target was hardly seen. In contrast, the CMOS camera was able to display the targets regardless of the camera-target distance under low illumination. Under high illumination, imaging quality given by both cameras was quite alike. In the second experiment as a fluorescence endoscope, the CMOS camera was capable of clearly showing the fluorescent-activated organs. The ultrahigh sensitivity CMOS HD endoscopic camera is expected to provide us with clear images under low illumination in addition to the fluorescent images under high illumination in the field of laparoscopic surgery.

An evolution of image source camera attribution approaches.

PubMed

Jahanirad, Mehdi; Wahab, Ainuddin Wahid Abdul; Anuar, Nor Badrul

2016-05-01

Camera attribution plays an important role in digital image forensics by providing the evidence and distinguishing characteristics of the origin of the digital image. It allows the forensic analyser to find the possible source camera which captured the image under investigation. However, in real-world applications, these approaches have faced many challenges due to the large set of multimedia data publicly available through photo sharing and social network sites, captured with uncontrolled conditions and undergone variety of hardware and software post-processing operations. Moreover, the legal system only accepts the forensic analysis of the digital image evidence if the applied camera attribution techniques are unbiased, reliable, nondestructive and widely accepted by the experts in the field. The aim of this paper is to investigate the evolutionary trend of image source camera attribution approaches from fundamental to practice, in particular, with the application of image processing and data mining techniques. Extracting implicit knowledge from images using intrinsic image artifacts for source camera attribution requires a structured image mining process. In this paper, we attempt to provide an introductory tutorial on the image processing pipeline, to determine the general classification of the features corresponding to different components for source camera attribution. The article also reviews techniques of the source camera attribution more comprehensively in the domain of the image forensics in conjunction with the presentation of classifying ongoing developments within the specified area. The classification of the existing source camera attribution approaches is presented based on the specific parameters, such as colour image processing pipeline, hardware- and software-related artifacts and the methods to extract such artifacts. The more recent source camera attribution approaches, which have not yet gained sufficient attention among image forensics researchers, are also critically analysed and further categorised into four different classes, namely, optical aberrations based, sensor camera fingerprints based, processing statistics based and processing regularities based, to present a classification. Furthermore, this paper aims to investigate the challenging problems, and the proposed strategies of such schemes based on the suggested taxonomy to plot an evolution of the source camera attribution approaches with respect to the subjective optimisation criteria over the last decade. The optimisation criteria were determined based on the strategies proposed to increase the detection accuracy, robustness and computational efficiency of source camera brand, model or device attribution. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

Composite video and graphics display for multiple camera viewing system in robotics and teleoperation

NASA Technical Reports Server (NTRS)

Diner, Daniel B. (Inventor); Venema, Steven C. (Inventor)

1991-01-01

A system for real-time video image display for robotics or remote-vehicle teleoperation is described that has at least one robot arm or remotely operated vehicle controlled by an operator through hand-controllers, and one or more television cameras and optional lighting element. The system has at least one television monitor for display of a television image from a selected camera and the ability to select one of the cameras for image display. Graphics are generated with icons of cameras and lighting elements for display surrounding the television image to provide the operator information on: the location and orientation of each camera and lighting element; the region of illumination of each lighting element; the viewed region and range of focus of each camera; which camera is currently selected for image display for each monitor; and when the controller coordinate for said robot arms or remotely operated vehicles have been transformed to correspond to coordinates of a selected or nonselected camera.

Composite video and graphics display for camera viewing systems in robotics and teleoperation

NASA Technical Reports Server (NTRS)

Diner, Daniel B. (Inventor); Venema, Steven C. (Inventor)

1993-01-01

A system for real-time video image display for robotics or remote-vehicle teleoperation is described that has at least one robot arm or remotely operated vehicle controlled by an operator through hand-controllers, and one or more television cameras and optional lighting element. The system has at least one television monitor for display of a television image from a selected camera and the ability to select one of the cameras for image display. Graphics are generated with icons of cameras and lighting elements for display surrounding the television image to provide the operator information on: the location and orientation of each camera and lighting element; the region of illumination of each lighting element; the viewed region and range of focus of each camera; which camera is currently selected for image display for each monitor; and when the controller coordinate for said robot arms or remotely operated vehicles have been transformed to correspond to coordinates of a selected or nonselected camera.

Indirectly Funded Research and Exploratory Development at the Applied Physics Laboratory, Fiscal Year 1978.

DTIC Science & Technology

1979-12-01

used to reduce costs ). The orbital data from the prototype ion composi- tion telescope will not only be of great scientific interest -pro- viding for...active device whose transfer function may be almost arbitrarily defined, and cost and production trends permit contemplation of networks containing...developing solid-state television camera systems based on CCD imagers. RICA hopes to produce a $500 color camera for consumer use. Fairchild and Texas

Multispectral fundus imaging for early detection of diabetic retinopathy

NASA Astrophysics Data System (ADS)

Beach, James M.; Tiedeman, James S.; Hopkins, Mark F.; Sabharwal, Yashvinder S.

1999-04-01

Functional imaging of the retina and associated structures may provide information for early assessment of risks of developing retinopathy in diabetic patients. Here we show results of retinal oximetry performed using multi-spectral reflectance imaging techniques to assess hemoglobin (Hb) oxygen saturation (OS) in blood vessels of the inner retina and oxygen utilization at the optic nerve in diabetic patients without retinopathy and early disease during experimental hyperglycemia. Retinal images were obtained through a fundus camera and simultaneously recorded at up to four wavelengths using image-splitting modules coupled to a digital camera. Changes in OS in large retinal vessels, in average OS in disk tissue, and in the reduced state of cytochrome oxidase (CO) at the disk were determined from changes in reflectance associated with the oxidation/reduction states of Hb and CO. Step to high sugar lowered venous oxygen saturation to a degree dependent on disease duration. Moderate increase in sugar produced higher levels of reduced CO in both the disk and surrounding tissue without a detectable change in average tissue OS. Results suggest that regulation of retinal blood supply and oxygen consumption are altered by hyperglycemia and that such functional changes are present before clinical signs of retinopathy.

Digital Camera with Apparatus for Authentication of Images Produced from an Image File

NASA Technical Reports Server (NTRS)

Friedman, Gary L. (Inventor)

1996-01-01

A digital camera equipped with a processor for authentication of images produced from an image file taken by the digital camera is provided. The digital camera processor has embedded therein a private key unique to it, and the camera housing has a public key that is so uniquely related to the private key that digital data encrypted with the private key may be decrypted using the public key. The digital camera processor comprises means for calculating a hash of the image file using a predetermined algorithm, and second means for encrypting the image hash with the private key, thereby producing a digital signature. The image file and the digital signature are stored in suitable recording means so they will be available together. Apparatus for authenticating the image file as being free of any alteration uses the public key for decrypting the digital signature, thereby deriving a secure image hash identical to the image hash produced by the digital camera and used to produce the digital signature. The authenticating apparatus calculates from the image file an image hash using the same algorithm as before. By comparing this last image hash with the secure image hash, authenticity of the image file is determined if they match. Other techniques to address time-honored methods of deception, such as attaching false captions or inducing forced perspectives, are included.

Image Alignment for Multiple Camera High Dynamic Range Microscopy.

PubMed

Eastwood, Brian S; Childs, Elisabeth C

2012-01-09

This paper investigates the problem of image alignment for multiple camera high dynamic range (HDR) imaging. HDR imaging combines information from images taken with different exposure settings. Combining information from multiple cameras requires an alignment process that is robust to the intensity differences in the images. HDR applications that use a limited number of component images require an alignment technique that is robust to large exposure differences. We evaluate the suitability for HDR alignment of three exposure-robust techniques. We conclude that image alignment based on matching feature descriptors extracted from radiant power images from calibrated cameras yields the most accurate and robust solution. We demonstrate the use of this alignment technique in a high dynamic range video microscope that enables live specimen imaging with a greater level of detail than can be captured with a single camera.

Image Alignment for Multiple Camera High Dynamic Range Microscopy

PubMed Central

Eastwood, Brian S.; Childs, Elisabeth C.

2012-01-01

This paper investigates the problem of image alignment for multiple camera high dynamic range (HDR) imaging. HDR imaging combines information from images taken with different exposure settings. Combining information from multiple cameras requires an alignment process that is robust to the intensity differences in the images. HDR applications that use a limited number of component images require an alignment technique that is robust to large exposure differences. We evaluate the suitability for HDR alignment of three exposure-robust techniques. We conclude that image alignment based on matching feature descriptors extracted from radiant power images from calibrated cameras yields the most accurate and robust solution. We demonstrate the use of this alignment technique in a high dynamic range video microscope that enables live specimen imaging with a greater level of detail than can be captured with a single camera. PMID:22545028

Multi-MGy Radiation Hardened Camera for Nuclear Facilities

DOE Office of Scientific and Technical Information (OSTI.GOV)

Girard, Sylvain; Boukenter, Aziz; Ouerdane, Youcef

There is an increasing interest in developing cameras for surveillance systems to monitor nuclear facilities or nuclear waste storages. Particularly, for today's and the next generation of nuclear facilities increasing safety requirements consecutive to Fukushima Daiichi's disaster have to be considered. For some applications, radiation tolerance needs to overcome doses in the MGy(SiO{sub 2}) range whereas the most tolerant commercial or prototypes products based on solid state image sensors withstand doses up to few kGy. The objective of this work is to present the radiation hardening strategy developed by our research groups to enhance the tolerance to ionizing radiations ofmore » the various subparts of these imaging systems by working simultaneously at the component and system design levels. Developing radiation-hardened camera implies to combine several radiation-hardening strategies. In our case, we decided not to use the simplest one, the shielding approach. This approach is efficient but limits the camera miniaturization and is not compatible with its future integration in remote-handling or robotic systems. Then, the hardening-by-component strategy appears mandatory to avoid the failure of one of the camera subparts at doses lower than the MGy. Concerning the image sensor itself, the used technology is a CMOS Image Sensor (CIS) designed by ISAE team with custom pixel designs used to mitigate the total ionizing dose (TID) effects that occur well below the MGy range in classical image sensors (e.g. Charge Coupled Devices (CCD), Charge Injection Devices (CID) and classical Active Pixel Sensors (APS)), such as the complete loss of functionality, the dark current increase and the gain drop. We'll present at the conference a comparative study between these radiation-hardened pixel radiation responses with respect to conventional ones, demonstrating the efficiency of the choices made. The targeted strategy to develop the complete radiation hard camera electronics will be exposed. Another important element of the camera is the optical system that transports the image from the scene to the image sensor. This arrangement of glass-based lenses is affected by radiations through two mechanisms: the radiation induced absorption and the radiation induced refractive index changes. The first one will limit the signal to noise ratio of the image whereas the second one will directly affect the resolution of the camera. We'll present at the conference a coupled simulation/experiment study of these effects for various commercial glasses and present vulnerability study of typical optical systems to radiations at MGy doses. The last very important part of the camera is the illumination system that can be based on various technologies of emitting devices like LED, SLED or lasers. The most promising solutions for high radiation doses will be presented at the conference. In addition to this hardening-by-component approach, the global radiation tolerance of the camera can be drastically improve by working at the system level, combining innovative approaches eg. for the optical and illumination systems. We'll present at the conference the developed approach allowing to extend the camera lifetime up to the MGy dose range. (authors)« less

A New Digital Holographic Instrument for Measuring Microphysical Properties of Contrails in the SASS (Subsonic Assessment) Program

NASA Technical Reports Server (NTRS)

Lawson, R. Paul

2000-01-01

SPEC incorporated designed, built and operated a new instrument, called a pi-Nephelometer, on the NASA DC-8 for the SUCCESS field project. The pi-Nephelometer casts an image of a particle on a 400,000 pixel solid-state camera by freezing the motion of the particle using a 25 ns pulsed, high-power (60 W) laser diode. Unique optical imaging and particle detection systems precisely detect particles and define the depth-of-field so that at least one particle in the image is almost always in focus. A powerful image processing engine processes frames from the solid-state camera, identifies and records regions of interest (i.e. particle images) in real time. Images of ice crystals are displayed and recorded with 5 micron pixel resolution. In addition, a scattered light system simultaneously measures the scattering phase function of the imaged particle. The system consists of twenty-eight 1-mm optical fibers connected to microlenses bonded on the surface of avalanche photo diodes (APDs). Data collected with the pi-Nephelometer during the SUCCESS field project was reported in a special issue of Geophysical Research Letters. The pi-Nephelometer provided the basis for development of a commercial imaging probe, called the cloud particle imager (CPI), which has been installed on several research aircraft and used in More than a dozen field programs.

Pre-flight and On-orbit Geometric Calibration of the Lunar Reconnaissance Orbiter Camera

NASA Astrophysics Data System (ADS)

Speyerer, E. J.; Wagner, R. V.; Robinson, M. S.; Licht, A.; Thomas, P. C.; Becker, K.; Anderson, J.; Brylow, S. M.; Humm, D. C.; Tschimmel, M.

2016-04-01

The Lunar Reconnaissance Orbiter Camera (LROC) consists of two imaging systems that provide multispectral and high resolution imaging of the lunar surface. The Wide Angle Camera (WAC) is a seven color push-frame imager with a 90∘ field of view in monochrome mode and 60∘ field of view in color mode. From the nominal 50 km polar orbit, the WAC acquires images with a nadir ground sampling distance of 75 m for each of the five visible bands and 384 m for the two ultraviolet bands. The Narrow Angle Camera (NAC) consists of two identical cameras capable of acquiring images with a ground sampling distance of 0.5 m from an altitude of 50 km. The LROC team geometrically calibrated each camera before launch at Malin Space Science Systems in San Diego, California and the resulting measurements enabled the generation of a detailed camera model for all three cameras. The cameras were mounted and subsequently launched on the Lunar Reconnaissance Orbiter (LRO) on 18 June 2009. Using a subset of the over 793000 NAC and 207000 WAC images of illuminated terrain collected between 30 June 2009 and 15 December 2013, we improved the interior and exterior orientation parameters for each camera, including the addition of a wavelength dependent radial distortion model for the multispectral WAC. These geometric refinements, along with refined ephemeris, enable seamless projections of NAC image pairs with a geodetic accuracy better than 20 meters and sub-pixel precision and accuracy when orthorectifying WAC images.

Applying and extending ISO/TC42 digital camera resolution standards to mobile imaging products

NASA Astrophysics Data System (ADS)

Williams, Don; Burns, Peter D.

2007-01-01

There are no fundamental differences between today's mobile telephone cameras and consumer digital still cameras that suggest many existing ISO imaging performance standards do not apply. To the extent that they have lenses, color filter arrays, detectors, apertures, image processing, and are hand held, there really are no operational or architectural differences. Despite this, there are currently differences in the levels of imaging performance. These are driven by physical and economic constraints, and image-capture conditions. Several ISO standards for resolution, well established for digital consumer digital cameras, require care when applied to the current generation of cell phone cameras. In particular, accommodation of optical flare, shading non-uniformity and distortion are recommended. We offer proposals for the application of existing ISO imaging resolution performance standards to mobile imaging products, and suggestions for extending performance standards to the characteristic behavior of camera phones.

NV-CMOS HD camera for day/night imaging

NASA Astrophysics Data System (ADS)

Vogelsong, T.; Tower, J.; Sudol, Thomas; Senko, T.; Chodelka, D.

2014-06-01

SRI International (SRI) has developed a new multi-purpose day/night video camera with low-light imaging performance comparable to an image intensifier, while offering the size, weight, ruggedness, and cost advantages enabled by the use of SRI's NV-CMOS HD digital image sensor chip. The digital video output is ideal for image enhancement, sharing with others through networking, video capture for data analysis, or fusion with thermal cameras. The camera provides Camera Link output with HD/WUXGA resolution of 1920 x 1200 pixels operating at 60 Hz. Windowing to smaller sizes enables operation at higher frame rates. High sensitivity is achieved through use of backside illumination, providing high Quantum Efficiency (QE) across the visible and near infrared (NIR) bands (peak QE <90%), as well as projected low noise (<2h+) readout. Power consumption is minimized in the camera, which operates from a single 5V supply. The NVCMOS HD camera provides a substantial reduction in size, weight, and power (SWaP) , ideal for SWaP-constrained day/night imaging platforms such as UAVs, ground vehicles, fixed mount surveillance, and may be reconfigured for mobile soldier operations such as night vision goggles and weapon sights. In addition the camera with the NV-CMOS HD imager is suitable for high performance digital cinematography/broadcast systems, biofluorescence/microscopy imaging, day/night security and surveillance, and other high-end applications which require HD video imaging with high sensitivity and wide dynamic range. The camera comes with an array of lens mounts including C-mount and F-mount. The latest test data from the NV-CMOS HD camera will be presented.

Toward an image compression algorithm for the high-resolution electronic still camera

NASA Technical Reports Server (NTRS)

Nerheim, Rosalee

1989-01-01

Taking pictures with a camera that uses a digital recording medium instead of film has the advantage of recording and transmitting images without the use of a darkroom or a courier. However, high-resolution images contain an enormous amount of information and strain data-storage systems. Image compression will allow multiple images to be stored in the High-Resolution Electronic Still Camera. The camera is under development at Johnson Space Center. Fidelity of the reproduced image and compression speed are of tantamount importance. Lossless compression algorithms are fast and faithfully reproduce the image, but their compression ratios will be unacceptably low due to noise in the front end of the camera. Future efforts will include exploring methods that will reduce the noise in the image and increase the compression ratio.

Object recognition through turbulence with a modified plenoptic camera

NASA Astrophysics Data System (ADS)

Wu, Chensheng; Ko, Jonathan; Davis, Christopher

2015-03-01

Atmospheric turbulence adds accumulated distortion to images obtained by cameras and surveillance systems. When the turbulence grows stronger or when the object is further away from the observer, increasing the recording device resolution helps little to improve the quality of the image. Many sophisticated methods to correct the distorted images have been invented, such as using a known feature on or near the target object to perform a deconvolution process, or use of adaptive optics. However, most of the methods depend heavily on the object's location, and optical ray propagation through the turbulence is not directly considered. Alternatively, selecting a lucky image over many frames provides a feasible solution, but at the cost of time. In our work, we propose an innovative approach to improving image quality through turbulence by making use of a modified plenoptic camera. This type of camera adds a micro-lens array to a traditional high-resolution camera to form a semi-camera array that records duplicate copies of the object as well as "superimposed" turbulence at slightly different angles. By performing several steps of image reconstruction, turbulence effects will be suppressed to reveal more details of the object independently (without finding references near the object). Meanwhile, the redundant information obtained by the plenoptic camera raises the possibility of performing lucky image algorithmic analysis with fewer frames, which is more efficient. In our work, the details of our modified plenoptic cameras and image processing algorithms will be introduced. The proposed method can be applied to coherently illuminated object as well as incoherently illuminated objects. Our result shows that the turbulence effect can be effectively suppressed by the plenoptic camera in the hardware layer and a reconstructed "lucky image" can help the viewer identify the object even when a "lucky image" by ordinary cameras is not achievable.

Pixel-based characterisation of CMOS high-speed camera systems

NASA Astrophysics Data System (ADS)

Weber, V.; Brübach, J.; Gordon, R. L.; Dreizler, A.

2011-05-01

Quantifying high-repetition rate laser diagnostic techniques for measuring scalars in turbulent combustion relies on a complete description of the relationship between detected photons and the signal produced by the detector. CMOS-chip based cameras are becoming an accepted tool for capturing high frame rate cinematographic sequences for laser-based techniques such as Particle Image Velocimetry (PIV) and Planar Laser Induced Fluorescence (PLIF) and can be used with thermographic phosphors to determine surface temperatures. At low repetition rates, imaging techniques have benefitted from significant developments in the quality of CCD-based camera systems, particularly with the uniformity of pixel response and minimal non-linearities in the photon-to-signal conversion. The state of the art in CMOS technology displays a significant number of technical aspects that must be accounted for before these detectors can be used for quantitative diagnostics. This paper addresses these issues.

Automatic source camera identification using the intrinsic lens radial distortion

NASA Astrophysics Data System (ADS)

Choi, Kai San; Lam, Edmund Y.; Wong, Kenneth K. Y.

2006-11-01

Source camera identification refers to the task of matching digital images with the cameras that are responsible for producing these images. This is an important task in image forensics, which in turn is a critical procedure in law enforcement. Unfortunately, few digital cameras are equipped with the capability of producing watermarks for this purpose. In this paper, we demonstrate that it is possible to achieve a high rate of accuracy in the identification by noting the intrinsic lens radial distortion of each camera. To reduce manufacturing cost, the majority of digital cameras are equipped with lenses having rather spherical surfaces, whose inherent radial distortions serve as unique fingerprints in the images. We extract, for each image, parameters from aberration measurements, which are then used to train and test a support vector machine classifier. We conduct extensive experiments to evaluate the success rate of a source camera identification with five cameras. The results show that this is a viable approach with high accuracy. Additionally, we also present results on how the error rates may change with images captured using various optical zoom levels, as zooming is commonly available in digital cameras.

A general Bayesian image reconstruction algorithm with entropy prior: Preliminary application to HST data

NASA Astrophysics Data System (ADS)

Nunez, Jorge; Llacer, Jorge

1993-10-01

This paper describes a general Bayesian iterative algorithm with entropy prior for image reconstruction. It solves the cases of both pure Poisson data and Poisson data with Gaussian readout noise. The algorithm maintains positivity of the solution; it includes case-specific prior information (default map) and flatfield corrections; it removes background and can be accelerated to be faster than the Richardson-Lucy algorithm. In order to determine the hyperparameter that balances the entropy and liklihood terms in the Bayesian approach, we have used a liklihood cross-validation technique. Cross-validation is more robust than other methods because it is less demanding in terms of the knowledge of exact data characteristics and of the point-spread function. We have used the algorithm to reconstruct successfully images obtained in different space-and ground-based imaging situations. It has been possible to recover most of the original intended capabilities of the Hubble Space Telescope (HST) wide field and planetary camera (WFPC) and faint object camera (FOC) from images obtained in their present state. Semireal simulations for the future wide field planetary camera 2 show that even after the repair of the spherical abberration problem, image reconstruction can play a key role in improving the resolution of the cameras, well beyond the design of the Hubble instruments. We also show that ground-based images can be reconstructed successfully with the algorithm. A technique which consists of dividing the CCD observations into two frames, with one-half the exposure time each, emerges as a recommended procedure for the utilization of the described algorithms. We have compared our technique with two commonly used reconstruction algorithms: the Richardson-Lucy and the Cambridge maximum entropy algorithms.

Survey of United States Commercial Satellites in Geosynchronous Earth Orbit

DTIC Science & Technology

1994-09-01

248 a. Imaging Sensors ...... ............ 248 (1) Return Beam Vidicon Camera . ... 249 (2) Scanners. ...... ............ 249 b. Nonimaging ...251 a. Imaging Microwave Sensors ......... .. 251 (1) Synthetic Aperture Radar . ... 251 b. Nonimaging Microwave Sensors ..... .. 252 (1) Radar...The stream of electrons travels alonq the axis oa the tube, constrained by focusing magnets, until it reaches the collector . Surrounding this electron

Measuring Positions of Objects using Two or More Cameras

NASA Technical Reports Server (NTRS)

Klinko, Steve; Lane, John; Nelson, Christopher

2008-01-01

An improved method of computing positions of objects from digitized images acquired by two or more cameras (see figure) has been developed for use in tracking debris shed by a spacecraft during and shortly after launch. The method is also readily adaptable to such applications as (1) tracking moving and possibly interacting objects in other settings in order to determine causes of accidents and (2) measuring positions of stationary objects, as in surveying. Images acquired by cameras fixed to the ground and/or cameras mounted on tracking telescopes can be used in this method. In this method, processing of image data starts with creation of detailed computer- aided design (CAD) models of the objects to be tracked. By rotating, translating, resizing, and overlaying the models with digitized camera images, parameters that characterize the position and orientation of the camera can be determined. The final position error depends on how well the centroids of the objects in the images are measured; how accurately the centroids are interpolated for synchronization of cameras; and how effectively matches are made to determine rotation, scaling, and translation parameters. The method involves use of the perspective camera model (also denoted the point camera model), which is one of several mathematical models developed over the years to represent the relationships between external coordinates of objects and the coordinates of the objects as they appear on the image plane in a camera. The method also involves extensive use of the affine camera model, in which the distance from the camera to an object (or to a small feature on an object) is assumed to be much greater than the size of the object (or feature), resulting in a truly two-dimensional image. The affine camera model does not require advance knowledge of the positions and orientations of the cameras. This is because ultimately, positions and orientations of the cameras and of all objects are computed in a coordinate system attached to one object as defined in its CAD model.

Earth elevation map production and high resolution sensing camera imaging analysis

NASA Astrophysics Data System (ADS)

Yang, Xiubin; Jin, Guang; Jiang, Li; Dai, Lu; Xu, Kai

2010-11-01

The Earth's digital elevation which impacts space camera imaging has prepared and imaging has analysed. Based on matching error that TDI CCD integral series request of the speed of image motion, statistical experimental methods-Monte Carlo method is used to calculate the distribution histogram of Earth's elevation in image motion compensated model which includes satellite attitude changes, orbital angular rate changes, latitude, longitude and the orbital inclination changes. And then, elevation information of the earth's surface from SRTM is read. Earth elevation map which produced for aerospace electronic cameras is compressed and spliced. It can get elevation data from flash according to the shooting point of latitude and longitude. If elevation data between two data, the ways of searching data uses linear interpolation. Linear interpolation can better meet the rugged mountains and hills changing requests. At last, the deviant framework and camera controller are used to test the character of deviant angle errors, TDI CCD camera simulation system with the material point corresponding to imaging point model is used to analyze the imaging's MTF and mutual correlation similarity measure, simulation system use adding cumulation which TDI CCD imaging exceeded the corresponding pixel horizontal and vertical offset to simulate camera imaging when stability of satellite attitude changes. This process is practicality. It can effectively control the camera memory space, and meet a very good precision TDI CCD camera in the request matches the speed of image motion and imaging.

Technique for improving the quality of images from digital cameras using ink-jet printers and smoothed RGB transfer curves

NASA Astrophysics Data System (ADS)

Sampat, Nitin; Grim, John F.; O'Hara, James E.

1998-04-01

The digital camera market is growing at an explosive rate. At the same time, the quality of photographs printed on ink- jet printers continues to improve. Most of the consumer cameras are designed with the monitor as the target output device and ont the printer. When a user is printing his images from a camera, he/she needs to optimize the camera and printer combination in order to maximize image quality. We describe the details of one such method for improving image quality using a AGFA digital camera and an ink jet printer combination. Using Adobe PhotoShop, we generated optimum red, green and blue transfer curves that match the scene content to the printers output capabilities. Application of these curves to the original digital image resulted in a print with more shadow detail, no loss of highlight detail, a smoother tone scale, and more saturated colors. The image also exhibited an improved tonal scale and visually more pleasing images than those captured and printed without any 'correction'. While we report the results for one camera-printer combination we tested this technique on numbers digital cameras and printer combinations and in each case produced a better looking image. We also discuss the problems we encountered in implementing this technique.

Myocardial perfusion imaging: Lessons learned and work to be done-update.

PubMed

Iskandrian, Ami E; Dilsizian, Vasken; Garcia, Ernest V; Beanlands, Rob S; Cerqueira, Manuel; Soman, Prem; Berman, Daniel S; Cuocolo, Alberto; Einstein, Andrew J; Morgan, Charity J; Hage, Fadi G; Schelbert, Heinrich R; Bax, Jeroen J; Wu, Joseph C; Shaw, Leslee J; Sadeghi, Mehran M; Tamaki, Nagara; Kaufmann, Philipp A; Gropler, Robert; Dorbala, Sharmila; Van Decker, William

2018-02-01

As the second term of our commitment to Journal begins, we, the editors, would like to reflect on a few topics that have relevance today. These include prognostication and paradigm shifts; Serial testing: How to handle data? Is the change in perfusion predictive of outcome and which one? Ischemia-guided therapy: fractional flow reserve vs perfusion vs myocardial blood flow; positron emission tomography (PET) imaging using Rubidium-82 vs N-13 ammonia vs F-18 Flurpiridaz; How to differentiate microvascular disease from 3-vessel disease by PET? The imaging scene outside the United States, what are the differences and similarities? Radiation exposure; Special issues with the new cameras? Is attenuation correction needed? Are there normal databases and are these specific to each camera system? And finally, hybrid imaging with single-photon emission tomography or PET combined with computed tomography angiography or coronary calcium score. We hope these topics are of interest to our readers.

Molecular Imaging in the College of Optical Sciences – An Overview of Two Decades of Instrumentation Development

PubMed Central

Furenlid, Lars R.; Barrett, Harrison H.; Barber, H. Bradford; Clarkson, Eric W.; Kupinski, Matthew A.; Liu, Zhonglin; Stevenson, Gail D.; Woolfenden, James M.

2015-01-01

During the past two decades, researchers at the University of Arizona’s Center for Gamma-Ray Imaging (CGRI) have explored a variety of approaches to gamma-ray detection, including scintillation cameras, solid-state detectors, and hybrids such as the intensified Quantum Imaging Device (iQID) configuration where a scintillator is followed by optical gain and a fast CCD or CMOS camera. We have combined these detectors with a variety of collimation schemes, including single and multiple pinholes, parallel-hole collimators, synthetic apertures, and anamorphic crossed slits, to build a large number of preclinical molecular-imaging systems that perform Single-Photon Emission Computed Tomography (SPECT), Positron Emission Tomography (PET), and X-Ray Computed Tomography (CT). In this paper, we discuss the themes and methods we have developed over the years to record and fully use the information content carried by every detected gamma-ray photon. PMID:26236069

Event-Driven Random-Access-Windowing CCD Imaging System

NASA Technical Reports Server (NTRS)

Monacos, Steve; Portillo, Angel; Ortiz, Gerardo; Alexander, James; Lam, Raymond; Liu, William

2004-01-01

A charge-coupled-device (CCD) based high-speed imaging system, called a realtime, event-driven (RARE) camera, is undergoing development. This camera is capable of readout from multiple subwindows [also known as regions of interest (ROIs)] within the CCD field of view. Both the sizes and the locations of the ROIs can be controlled in real time and can be changed at the camera frame rate. The predecessor of this camera was described in High-Frame-Rate CCD Camera Having Subwindow Capability (NPO- 30564) NASA Tech Briefs, Vol. 26, No. 12 (December 2002), page 26. The architecture of the prior camera requires tight coupling between camera control logic and an external host computer that provides commands for camera operation and processes pixels from the camera. This tight coupling limits the attainable frame rate and functionality of the camera. The design of the present camera loosens this coupling to increase the achievable frame rate and functionality. From a host computer perspective, the readout operation in the prior camera was defined on a per-line basis; in this camera, it is defined on a per-ROI basis. In addition, the camera includes internal timing circuitry. This combination of features enables real-time, event-driven operation for adaptive control of the camera. Hence, this camera is well suited for applications requiring autonomous control of multiple ROIs to track multiple targets moving throughout the CCD field of view. Additionally, by eliminating the need for control intervention by the host computer during the pixel readout, the present design reduces ROI-readout times to attain higher frame rates. This camera (see figure) includes an imager card consisting of a commercial CCD imager and two signal-processor chips. The imager card converts transistor/ transistor-logic (TTL)-level signals from a field programmable gate array (FPGA) controller card. These signals are transmitted to the imager card via a low-voltage differential signaling (LVDS) cable assembly. The FPGA controller card is connected to the host computer via a standard peripheral component interface (PCI).

You are here: Earth as seen from Mars

NASA Image and Video Library

2004-03-11

This is the first image ever taken of Earth from the surface of a planet beyond the Moon. It was taken by the Mars Exploration Rover Spirit one hour before sunrise on the 63rd martian day, or sol, of its mission. The image is a mosaic of images taken by the rover's navigation camera showing a broad view of the sky, and an image taken by the rover's panoramic camera of Earth. The contrast in the panoramic camera image was increased two times to make Earth easier to see. The inset shows a combination of four panoramic camera images zoomed in on Earth. The arrow points to Earth. Earth was too faint to be detected in images taken with the panoramic camera's color filters. http://photojournal.jpl.nasa.gov/catalog/PIA05547

The sequence measurement system of the IR camera

NASA Astrophysics Data System (ADS)

Geng, Ai-hui; Han, Hong-xia; Zhang, Hai-bo

2011-08-01

Currently, the IR cameras are broadly used in the optic-electronic tracking, optic-electronic measuring, fire control and optic-electronic countermeasure field, but the output sequence of the most presently applied IR cameras in the project is complex and the giving sequence documents from the leave factory are not detailed. Aiming at the requirement that the continuous image transmission and image procession system need the detailed sequence of the IR cameras, the sequence measurement system of the IR camera is designed, and the detailed sequence measurement way of the applied IR camera is carried out. The FPGA programming combined with the SignalTap online observation way has been applied in the sequence measurement system, and the precise sequence of the IR camera's output signal has been achieved, the detailed document of the IR camera has been supplied to the continuous image transmission system, image processing system and etc. The sequence measurement system of the IR camera includes CameraLink input interface part, LVDS input interface part, FPGA part, CameraLink output interface part and etc, thereinto the FPGA part is the key composed part in the sequence measurement system. Both the video signal of the CmaeraLink style and the video signal of LVDS style can be accepted by the sequence measurement system, and because the image processing card and image memory card always use the CameraLink interface as its input interface style, the output signal style of the sequence measurement system has been designed into CameraLink interface. The sequence measurement system does the IR camera's sequence measurement work and meanwhile does the interface transmission work to some cameras. Inside the FPGA of the sequence measurement system, the sequence measurement program, the pixel clock modification, the SignalTap file configuration and the SignalTap online observation has been integrated to realize the precise measurement to the IR camera. Te sequence measurement program written by the verilog language combining the SignalTap tool on line observation can count the line numbers in one frame, pixel numbers in one line and meanwhile account the line offset and row offset of the image. Aiming at the complex sequence of the IR camera's output signal, the sequence measurement system of the IR camera accurately measures the sequence of the project applied camera, supplies the detailed sequence document to the continuous system such as image processing system and image transmission system and gives out the concrete parameters of the fval, lval, pixclk, line offset and row offset. The experiment shows that the sequence measurement system of the IR camera can get the precise sequence measurement result and works stably, laying foundation for the continuous system.

A new concept of real-time security camera monitoring with privacy protection by masking moving objects

NASA Astrophysics Data System (ADS)

Yabuta, Kenichi; Kitazawa, Hitoshi; Tanaka, Toshihisa

2006-02-01

Recently, monitoring cameras for security have been extensively increasing. However, it is normally difficult to know when and where we are monitored by these cameras and how the recorded images are stored and/or used. Therefore, how to protect privacy in the recorded images is a crucial issue. In this paper, we address this problem and introduce a framework for security monitoring systems considering the privacy protection. We state requirements for monitoring systems in this framework. We propose a possible implementation that satisfies the requirements. To protect privacy of recorded objects, they are made invisible by appropriate image processing techniques. Moreover, the original objects are encrypted and watermarked into the image with the "invisible" objects, which is coded by the JPEG standard. Therefore, the image decoded by a normal JPEG viewer includes the objects that are unrecognized or invisible. We also introduce in this paper a so-called "special viewer" in order to decrypt and display the original objects. This special viewer can be used by limited users when necessary for crime investigation, etc. The special viewer allows us to choose objects to be decoded and displayed. Moreover, in this proposed system, real-time processing can be performed, since no future frame is needed to generate a bitstream.

CIFAR10-DVS: An Event-Stream Dataset for Object Classification

PubMed Central

Li, Hongmin; Liu, Hanchao; Ji, Xiangyang; Li, Guoqi; Shi, Luping

2017-01-01

Neuromorphic vision research requires high-quality and appropriately challenging event-stream datasets to support continuous improvement of algorithms and methods. However, creating event-stream datasets is a time-consuming task, which needs to be recorded using the neuromorphic cameras. Currently, there are limited event-stream datasets available. In this work, by utilizing the popular computer vision dataset CIFAR-10, we converted 10,000 frame-based images into 10,000 event streams using a dynamic vision sensor (DVS), providing an event-stream dataset of intermediate difficulty in 10 different classes, named as “CIFAR10-DVS.” The conversion of event-stream dataset was implemented by a repeated closed-loop smooth (RCLS) movement of frame-based images. Unlike the conversion of frame-based images by moving the camera, the image movement is more realistic in respect of its practical applications. The repeated closed-loop image movement generates rich local intensity changes in continuous time which are quantized by each pixel of the DVS camera to generate events. Furthermore, a performance benchmark in event-driven object classification is provided based on state-of-the-art classification algorithms. This work provides a large event-stream dataset and an initial benchmark for comparison, which may boost algorithm developments in even-driven pattern recognition and object classification. PMID:28611582

CIFAR10-DVS: An Event-Stream Dataset for Object Classification.

PubMed

Li, Hongmin; Liu, Hanchao; Ji, Xiangyang; Li, Guoqi; Shi, Luping

2017-01-01

Neuromorphic vision research requires high-quality and appropriately challenging event-stream datasets to support continuous improvement of algorithms and methods. However, creating event-stream datasets is a time-consuming task, which needs to be recorded using the neuromorphic cameras. Currently, there are limited event-stream datasets available. In this work, by utilizing the popular computer vision dataset CIFAR-10, we converted 10,000 frame-based images into 10,000 event streams using a dynamic vision sensor (DVS), providing an event-stream dataset of intermediate difficulty in 10 different classes, named as "CIFAR10-DVS." The conversion of event-stream dataset was implemented by a repeated closed-loop smooth (RCLS) movement of frame-based images. Unlike the conversion of frame-based images by moving the camera, the image movement is more realistic in respect of its practical applications. The repeated closed-loop image movement generates rich local intensity changes in continuous time which are quantized by each pixel of the DVS camera to generate events. Furthermore, a performance benchmark in event-driven object classification is provided based on state-of-the-art classification algorithms. This work provides a large event-stream dataset and an initial benchmark for comparison, which may boost algorithm developments in even-driven pattern recognition and object classification.

The diagnosing of plasmas using spectroscopy and imaging on Proto-MPEX

NASA Astrophysics Data System (ADS)

Baldwin, K. A.; Biewer, T. M.; Crouse Powers, J.; Hardin, R.; Johnson, S.; McCleese, A.; Shaw, G. C.; Showers, M.; Skeen, C.

2015-11-01

The Prototype Material Plasma Exposure eXperiment (Proto-MPEX) is a linear plasma device being developed at Oak Ridge National Laboratory (ORNL). This machine plans to study plasma-material interaction (PMI) physics relevant to future fusion reactors. We tested and learned to use tools of spectroscopy and imaging. These tools consist of a spectrometer, a high speed camera, an infrared camera, and a thermocouple. The spectrometer measures the color of the light from the plasma and its intensity. We also used a high speed camera to see how the magnetic field acts on the plasma, and how it is heated to the fourth state of matter. The thermocouples measure the temperature of the objects they are placed against, which in this case are the end plates of the machine. We also used the infrared camera to see the heat pattern of the plasma on the end plates. Data from these instruments will be shown. This work was supported by the US. D.O.E. contract DE-AC05-00OR22725, and the Oak Ridge Associated Universities ARC program.

A new high-speed IR camera system

NASA Technical Reports Server (NTRS)

Travis, Jeffrey W.; Shu, Peter K.; Jhabvala, Murzy D.; Kasten, Michael S.; Moseley, Samuel H.; Casey, Sean C.; Mcgovern, Lawrence K.; Luers, Philip J.; Dabney, Philip W.; Kaipa, Ravi C.

1994-01-01

A multi-organizational team at the Goddard Space Flight Center is developing a new far infrared (FIR) camera system which furthers the state of the art for this type of instrument by the incorporating recent advances in several technological disciplines. All aspects of the camera system are optimized for operation at the high data rates required for astronomical observations in the far infrared. The instrument is built around a Blocked Impurity Band (BIB) detector array which exhibits responsivity over a broad wavelength band and which is capable of operating at 1000 frames/sec, and consists of a focal plane dewar, a compact camera head electronics package, and a Digital Signal Processor (DSP)-based data system residing in a standard 486 personal computer. In this paper we discuss the overall system architecture, the focal plane dewar, and advanced features and design considerations for the electronics. This system, or one derived from it, may prove useful for many commercial and/or industrial infrared imaging or spectroscopic applications, including thermal machine vision for robotic manufacturing, photographic observation of short-duration thermal events such as combustion or chemical reactions, and high-resolution surveillance imaging.

STS-99 Commander Kregel poses with EARTHKAM camera on OV-105's flight deck

NASA Image and Video Library

2000-03-30

STS099-314-035 (11-22 February 2000) ---Astronaut Kevin R. Kregel, mission commander, works with camera equipment, which was used for the EarthKAM project. The camera stayed busy throughout the 11-day mission taking vertical imagery of the Earth points of opportunity for the project. Students across the United States and in France, Germany and Japan took photos throughout the STS-99 mission. And they are using these new photos, plus all the images already available in the EarthKAM system, to enhance their classroom learning in Earth and space science, social studies, geography, mathematics and more.

Mars Descent Imager for Curiosity

NASA Image and Video Library

2010-07-19

A pocketknife provides scale for this image of the Mars Descent Imager camera; the camera will fly on the Curiosity rover of NASA Mars Science Laboratory mission. Malin Space Science Systems, San Diego, Calif., supplied the camera for the mission.

New generation of meteorology cameras

NASA Astrophysics Data System (ADS)

Janout, Petr; Blažek, Martin; Páta, Petr

2017-12-01

A new generation of the WILLIAM (WIde-field aLL-sky Image Analyzing Monitoring system) camera includes new features such as monitoring of rain and storm clouds during the day observation. Development of the new generation of weather monitoring cameras responds to the demand for monitoring of sudden weather changes. However, new WILLIAM cameras are ready to process acquired image data immediately, release warning against sudden torrential rains, and send it to user's cell phone and email. Actual weather conditions are determined from image data, and results of image processing are complemented by data from sensors of temperature, humidity, and atmospheric pressure. In this paper, we present the architecture, image data processing algorithms of mentioned monitoring camera and spatially-variant model of imaging system aberrations based on Zernike polynomials.

Practical aspects of modern interferometry for optical manufacturing quality control: Part 2

NASA Astrophysics Data System (ADS)

Smythe, Robert

2012-07-01

Modern phase shifting interferometers enable the manufacture of optical systems that drive the global economy. Semiconductor chips, solid-state cameras, cell phone cameras, infrared imaging systems, space based satellite imaging and DVD and Blu-Ray disks are all enabled by phase shifting interferometers. Theoretical treatments of data analysis and instrument design advance the technology but often are not helpful towards the practical use of interferometers. An understanding of the parameters that drive system performance is critical to produce useful results. Any interferometer will produce a data map and results; this paper, in three parts, reviews some of the key issues to minimize error sources in that data and provide a valid measurement.

Practical aspects of modern interferometry for optical manufacturing quality control, Part 3

NASA Astrophysics Data System (ADS)

Smythe, Robert A.

2012-09-01

Modern phase shifting interferometers enable the manufacture of optical systems that drive the global economy. Semiconductor chips, solid-state cameras, cell phone cameras, infrared imaging systems, space-based satellite imaging, and DVD and Blu-Ray disks are all enabled by phase-shifting interferometers. Theoretical treatments of data analysis and instrument design advance the technology but often are not helpful toward the practical use of interferometers. An understanding of the parameters that drive the system performance is critical to produce useful results. Any interferometer will produce a data map and results; this paper, in three parts, reviews some of the key issues to minimize error sources in that data and provide a valid measurement.

QWIP technology for both military and civilian applications

NASA Astrophysics Data System (ADS)

Gunapala, Sarath D.; Kukkonen, Carl A.; Sirangelo, Mark N.; McQuiston, Barbara K.; Chehayeb, Riad; Kaufmann, M.

2001-10-01

Advanced thermal imaging infrared cameras have been a cost effective and reliable method to obtain the temperature of objects. Quantum Well Infrared Photodetector (QWIP) based thermal imaging systems have advanced the state-of-the-art and are the most sensitive commercially available thermal systems. QWIP Technologies LLC, under exclusive agreement with Caltech University, is currently manufacturing the QWIP-ChipTM, a 320 X 256 element, bound-to-quasibound QWIP FPA. The camera performance falls within the long-wave IR band, spectrally peaked at 8.5 μm. The camera is equipped with a 32-bit floating-point digital signal processor combined with multi- tasking software, delivering a digital acquisition resolution of 12-bits using nominal power consumption of less than 50 Watts. With a variety of video interface options, remote control capability via an RS-232 connection, and an integrated control driver circuit to support motorized zoom and focus- compatible lenses, this camera design has excellent application in both the military and commercial sector. In the area of remote sensing, high-performance QWIP systems can be used for high-resolution, target recognition as part of a new system of airborne platforms (including UAVs). Such systems also have direct application in law enforcement, surveillance, industrial monitoring and road hazard detection systems. This presentation will cover the current performance of the commercial QWIP cameras, conceptual platform systems and advanced image processing for use in both military remote sensing and civilian applications currently being developed in road hazard monitoring.

Phenology cameras observing boreal ecosystems of Finland

NASA Astrophysics Data System (ADS)

Peltoniemi, Mikko; Böttcher, Kristin; Aurela, Mika; Kolari, Pasi; Tanis, Cemal Melih; Linkosalmi, Maiju; Loehr, John; Metsämäki, Sari; Nadir Arslan, Ali

2016-04-01

Cameras have become useful tools for monitoring seasonality of ecosystems. Low-cost cameras facilitate validation of other measurements and allow extracting some key ecological features and moments from image time series. We installed a network of phenology cameras at selected ecosystem research sites in Finland. Cameras were installed above, on the level, or/and below the canopies. Current network hosts cameras taking time lapse images in coniferous and deciduous forests as well as at open wetlands offering thus possibilities to monitor various phenological and time-associated events and elements. In this poster, we present our camera network and give examples of image series use for research. We will show results about the stability of camera derived color signals, and based on that discuss about the applicability of cameras in monitoring time-dependent phenomena. We will also present results from comparisons between camera-derived color signal time series and daily satellite-derived time series (NVDI, NDWI, and fractional snow cover) from the Moderate Resolution Imaging Spectrometer (MODIS) at selected spruce and pine forests and in a wetland. We will discuss the applicability of cameras in supporting phenological observations derived from satellites, by considering the possibility of cameras to monitor both above and below canopy phenology and snow.

High speed fluorescence imaging with compressed ultrafast photography

NASA Astrophysics Data System (ADS)

Thompson, J. V.; Mason, J. D.; Beier, H. T.; Bixler, J. N.

2017-02-01

Fluorescent lifetime imaging is an optical technique that facilitates imaging molecular interactions and cellular functions. Because the excited lifetime of a fluorophore is sensitive to its local microenvironment,1, 2 measurement of fluorescent lifetimes can be used to accurately detect regional changes in temperature, pH, and ion concentration. However, typical state of the art fluorescent lifetime methods are severely limited when it comes to acquisition time (on the order of seconds to minutes) and video rate imaging. Here we show that compressed ultrafast photography (CUP) can be used in conjunction with fluorescent lifetime imaging to overcome these acquisition rate limitations. Frame rates up to one hundred billion frames per second have been demonstrated with compressed ultrafast photography using a streak camera.3 These rates are achieved by encoding time in the spatial direction with a pseudo-random binary pattern. The time domain information is then reconstructed using a compressed sensing algorithm, resulting in a cube of data (x,y,t) for each readout image. Thus, application of compressed ultrafast photography will allow us to acquire an entire fluorescent lifetime image with a single laser pulse. Using a streak camera with a high-speed CMOS camera, acquisition rates of 100 frames per second can be achieved, which will significantly enhance our ability to quantitatively measure complex biological events with high spatial and temporal resolution. In particular, we will demonstrate the ability of this technique to do single-shot fluorescent lifetime imaging of cells and microspheres.

Light-Directed Ranging System Implementing Single Camera System for Telerobotics Applications

NASA Technical Reports Server (NTRS)

Wells, Dennis L. (Inventor); Li, Larry C. (Inventor); Cox, Brian J. (Inventor)

1997-01-01

A laser-directed ranging system has utility for use in various fields, such as telerobotics applications and other applications involving physically handicapped individuals. The ranging system includes a single video camera and a directional light source such as a laser mounted on a camera platform, and a remotely positioned operator. In one embodiment, the position of the camera platform is controlled by three servo motors to orient the roll axis, pitch axis and yaw axis of the video cameras, based upon an operator input such as head motion. The laser is offset vertically and horizontally from the camera, and the laser/camera platform is directed by the user to point the laser and the camera toward a target device. The image produced by the video camera is processed to eliminate all background images except for the spot created by the laser. This processing is performed by creating a digital image of the target prior to illumination by the laser, and then eliminating common pixels from the subsequent digital image which includes the laser spot. A reference point is defined at a point in the video frame, which may be located outside of the image area of the camera. The disparity between the digital image of the laser spot and the reference point is calculated for use in a ranging analysis to determine range to the target.

Endockscope: using mobile technology to create global point of service endoscopy.

PubMed

Sohn, William; Shreim, Samir; Yoon, Renai; Huynh, Victor B; Dash, Atreya; Clayman, Ralph; Lee, Hak J

2013-09-01

Recent advances and the widespread availability of smartphones have ushered in a new wave of innovations in healthcare. We present our initial experience with Endockscope, a new docking system that optimizes the coupling of the iPhone 4S with modern endoscopes. Using the United States Air Force resolution target, we compared the image resolution (line pairs/mm) of a flexible cystoscope coupled to the Endockscope+iPhone to the Storz high definition (HD) camera (H3-Z Versatile). We then used the Munsell ColorChecker chart to compare the color resolution with a 0° laparoscope. Furthermore, 12 expert endoscopists blindly compared and evaluated images from a porcine model using a cystoscope and ureteroscope for both systems. Finally, we also compared the cost (average of two company listed prices) and weight (lb) of the two systems. Overall, the image resolution allowed by the Endockscope was identical to the traditional HD camera (4.49 vs 4.49 lp/mm). Red (ΔE=9.26 vs 9.69) demonstrated better color resolution for iPhone, but green (ΔE=7.76 vs 10.95), and blue (ΔE=12.35 vs 14.66) revealed better color resolution with the Storz HD camera. Expert reviews of cystoscopic images acquired with the HD camera were superior in image, color, and overall quality (P=0.002, 0.042, and 0.003). In contrast, the ureteroscopic reviews yielded no statistical difference in image, color, and overall (P=1, 0.203, and 0.120) quality. The overall cost of the Endockscope+iPhone was $154 compared with $46,623 for a standard HD system. The weight of the mobile-coupled system was 0.47 lb and 1.01 lb for the Storz HD camera. Endockscope demonstrated feasibility of coupling endoscopes to a smartphone. The lighter and inexpensive Endockscope acquired images of the same resolution and acceptable color resolution. When evaluated by expert endoscopists, the quality of the images overall were equivalent for flexible ureteroscopy and somewhat inferior, but still acceptable for flexible cystoscopy.

Endockscope: Using Mobile Technology to Create Global Point of Service Endoscopy

PubMed Central

Sohn, William; Shreim, Samir; Yoon, Renai; Huynh, Victor B.; Dash, Atreya; Clayman, Ralph

2013-01-01

Abstract Background and Purpose Recent advances and the widespread availability of smartphones have ushered in a new wave of innovations in healthcare. We present our initial experience with Endockscope, a new docking system that optimizes the coupling of the iPhone 4S with modern endoscopes. Materials and Methods Using the United States Air Force resolution target, we compared the image resolution (line pairs/mm) of a flexible cystoscope coupled to the Endockscope+iPhone to the Storz high definition (HD) camera (H3-Z Versatile). We then used the Munsell ColorChecker chart to compare the color resolution with a 0° laparoscope. Furthermore, 12 expert endoscopists blindly compared and evaluated images from a porcine model using a cystoscope and ureteroscope for both systems. Finally, we also compared the cost (average of two company listed prices) and weight (lb) of the two systems. Results Overall, the image resolution allowed by the Endockscope was identical to the traditional HD camera (4.49 vs 4.49 lp/mm). Red (ΔE=9.26 vs 9.69) demonstrated better color resolution for iPhone, but green (ΔE=7.76 vs 10.95), and blue (ΔE=12.35 vs 14.66) revealed better color resolution with the Storz HD camera. Expert reviews of cystoscopic images acquired with the HD camera were superior in image, color, and overall quality (P=0.002, 0.042, and 0.003). In contrast, the ureteroscopic reviews yielded no statistical difference in image, color, and overall (P=1, 0.203, and 0.120) quality. The overall cost of the Endockscope+iPhone was $154 compared with $46,623 for a standard HD system. The weight of the mobile-coupled system was 0.47 lb and 1.01 lb for the Storz HD camera. Conclusion Endockscope demonstrated feasibility of coupling endoscopes to a smartphone. The lighter and inexpensive Endockscope acquired images of the same resolution and acceptable color resolution. When evaluated by expert endoscopists, the quality of the images overall were equivalent for flexible ureteroscopy and somewhat inferior, but still acceptable for flexible cystoscopy. PMID:23701228

Digital Image Correlation: Metrological Characterization in Mechanical Analysis

NASA Astrophysics Data System (ADS)

Petrella, Orsola; Signore, Davide; Caramuta, Pietro; Toscano, Cinzia; Ferraiuolo, Michele

2017-04-01

The Digital Image Correlation (DIC) is a newly developed optical technique that is spreading in all engineering sectors because it allows the non-destructive estimation of the entire surface deformation without any contact with the component under analysis. These characteristics make the DIC very appealing in all the cases the global deformation state is to be known without using strain gages, which are the most used measuring device. The DIC is applicable to any material subjected to distortion caused by either thermal or mechanical load, allowing to obtain high-definition mapping of displacements and deformations. That is why in the civil and the transportation industry, DIC is very useful for studying the behavior of metallic materials as well as of composite materials. DIC is also used in the medical field for the characterization of the local strain field of the vascular tissues surface subjected to uniaxial tensile loading. DIC can be carried out in the two dimension mode (2D DIC) if a single camera is used or in a three dimension mode (3D DIC) if two cameras are involved. Each point of the test surface framed by the cameras can be associated with a specific pixel of the image and the coordinates of each point are calculated knowing the relative distance between the two cameras together with their orientation. In both arrangements, when a component is subjected to a load, several images related to different deformation states can be are acquired through the cameras. A specific software analyzes the images via the mutual correlation between the reference image (obtained without any applied load) and those acquired during the deformation giving the relative displacements. In this paper, a Metrological Characterization of the Digital Image Correlation is performed on aluminum and composite targets both in static and dynamic loading conditions by comparison between DIC and strain gauges measures. In the static test, interesting results have been obtained thanks to an excellent agreement between the two measuring techniques. In addition, the deformation detected by the DIC is compliant with the result of a FEM simulation In the dynamic test the DIC was able to follow with a good accuracy the periodic deformation of the specimen giving results coherent with the ones given by FEM simulation. In both situations, it was seen that the DIC measurement accuracy depends on several parameters such as the optical focusing, the parameters chosen to perform the mutual correlation between the images and, finally, the reference points on image to be analyzed. In the future the influence of these parameters will be studied and a method to increase the accuracy of the measurements will be developed in accordance with the requirements of the industries especially of the aerospace one.

Design principles and applications of a cooled CCD camera for electron microscopy.

PubMed

Faruqi, A R

1998-01-01

Cooled CCD cameras offer a number of advantages in recording electron microscope images with CCDs rather than film which include: immediate availability of the image in a digital format suitable for further computer processing, high dynamic range, excellent linearity and a high detective quantum efficiency for recording electrons. In one important respect however, film has superior properties: the spatial resolution of CCD detectors tested so far (in terms of point spread function or modulation transfer function) are inferior to film and a great deal of our effort has been spent in designing detectors with improved spatial resolution. Various instrumental contributions to spatial resolution have been analysed and in this paper we discuss the contribution of the phosphor-fibre optics system in this measurement. We have evaluated the performance of a number of detector components and parameters, e.g. different phosphors (and a scintillator), optical coupling with lens or fibre optics with various demagnification factors, to improve the detector performance. The camera described in this paper, which is based on this analysis, uses a tapered fibre optics coupling between the phosphor and the CCD and is installed on a Philips CM12 electron microscope equipped to perform cryo-microscopy. The main use of the camera so far has been in recording electron diffraction patterns from two dimensional crystals of bacteriorhodopsin--from wild type and from different trapped states during the photocycle. As one example of the type of data obtained with the CCD camera a two dimensional Fourier projection map from the trapped O-state is also included. With faster computers, it will soon be possible to undertake this type of work on an on-line basis. Also, with improvements in detector size and resolution, CCD detectors, already ideal for diffraction, will be able to compete with film in the recording of high resolution images.

A digital gigapixel large-format tile-scan camera.

PubMed

Ben-Ezra, M

2011-01-01

Although the resolution of single-lens reflex (SLR) and medium-format digital cameras has increased in recent years, applications for cultural-heritage preservation and computational photography require even higher resolutions. Addressing this issue, a large-format cameras' large image planes can achieve very high resolution without compromising pixel size and thus can provide high-quality, high-resolution images.This digital large-format tile scan camera can acquire high-quality, high-resolution images of static scenes. It employs unique calibration techniques and a simple algorithm for focal-stack processing of very large images with significant magnification variations. The camera automatically collects overlapping focal stacks and processes them into a high-resolution, extended-depth-of-field image.

Feasibility of SPECT myocardial perfusion imaging in the super-obese using a multi-head semiconductor camera with attenuation correction.

PubMed

DeCicco, Anthony E; Sokil, Alexis B; Marhefka, Gregary D; Reist, Kirk; Hansen, Christopher L

2015-04-01

Obesity is not only associated with an increased risk of coronary artery disease, but also decreases the accuracy of many diagnostic modalities pertinent to this disease. Advances in myocardial perfusion imaging (MPI) have mitigated somewhat the effects of obesity, although the feasibility of MPI in the super-obese (defined as a BMI > 50) is currently untested. We undertook this study to assess the practicality of MPI in the super-obese using a multi-headed solid-state gamma camera with attenuation correction. We retrospectively identified consecutive super-obese patients referred for MPI at our institution. The images were interpreted by 3 blinded, experienced readers and graded for quality and diagnosis, and subjectively evaluated the contribution of attenuation correction. Clinical follow-up was obtained from review of medical records. 72 consecutive super-obese patients were included. Their BMI ranged from 50 to 67 (55.7 ± 5.1). Stress image quality was considered good or excellent in 45 (63%), satisfactory in 24 (33%), poor in 3 (4%), and uninterpretable in 0 patients. Rest images were considered good or excellent in 34 (49%), satisfactory in 23 (33%), poor in 13 (19%), and uninterpretable in 0 patients. Attenuation correction changed the interpretation in 34 (47%) of studies. MPI is feasible and provides acceptable image quality for super-obese patients, although it may be camera and protocol dependent.

Color constancy by characterization of illumination chromaticity

NASA Astrophysics Data System (ADS)

Nikkanen, Jarno T.

2011-05-01

Computational color constancy algorithms play a key role in achieving desired color reproduction in digital cameras. Failure to estimate illumination chromaticity correctly will result in invalid overall colour cast in the image that will be easily detected by human observers. A new algorithm is presented for computational color constancy. Low computational complexity and low memory requirement make the algorithm suitable for resource-limited camera devices, such as consumer digital cameras and camera phones. Operation of the algorithm relies on characterization of the range of possible illumination chromaticities in terms of camera sensor response. The fact that only illumination chromaticity is characterized instead of the full color gamut, for example, increases robustness against variations in sensor characteristics and against failure of diagonal model of illumination change. Multiple databases are used in order to demonstrate the good performance of the algorithm in comparison to the state-of-the-art color constancy algorithms.

Geometric rectification of camera-captured document images.

PubMed

Liang, Jian; DeMenthon, Daniel; Doermann, David

2008-04-01

Compared to typical scanners, handheld cameras offer convenient, flexible, portable, and non-contact image capture, which enables many new applications and breathes new life into existing ones. However, camera-captured documents may suffer from distortions caused by non-planar document shape and perspective projection, which lead to failure of current OCR technologies. We present a geometric rectification framework for restoring the frontal-flat view of a document from a single camera-captured image. Our approach estimates 3D document shape from texture flow information obtained directly from the image without requiring additional 3D/metric data or prior camera calibration. Our framework provides a unified solution for both planar and curved documents and can be applied in many, especially mobile, camera-based document analysis applications. Experiments show that our method produces results that are significantly more OCR compatible than the original images.

The Art of Astrophotography

NASA Astrophysics Data System (ADS)

Morison, Ian

2017-02-01

1. Imaging star trails; 2. Imaging a constellation with a DSLR and tripod; 3. Imaging the Milky Way with a DSLR and tracking mount; 4. Imaging the Moon with a compact camera or smartphone; 5. Imaging the Moon with a DSLR; 6. Imaging the Pleiades Cluster with a DSLR and small refractor; 7. Imaging the Orion Nebula, M42, with a modified Canon DSLR; 8. Telescopes and their accessories for use in astroimaging; 9. Towards stellar excellence; 10. Cooling a DSLR camera to reduce sensor noise; 11. Imaging the North American and Pelican Nebulae; 12. Combating light pollution - the bane of astrophotographers; 13. Imaging planets with an astronomical video camera or Canon DSLR; 14. Video imaging the Moon with a webcam or DSLR; 15. Imaging the Sun in white light; 16. Imaging the Sun in the light of its H-alpha emission; 17. Imaging meteors; 18. Imaging comets; 19. Using a cooled 'one shot colour' camera; 20. Using a cooled monochrome CCD camera; 21. LRGB colour imaging; 22. Narrow band colour imaging; Appendix A. Telescopes for imaging; Appendix B. Telescope mounts; Appendix C. The effects of the atmosphere; Appendix D. Auto guiding; Appendix E. Image calibration; Appendix F. Practical aspects of astroimaging.

Comparison and evaluation of datasets for off-angle iris recognition

NASA Astrophysics Data System (ADS)

Kurtuncu, Osman M.; Cerme, Gamze N.; Karakaya, Mahmut

2016-05-01

In this paper, we investigated the publicly available iris recognition datasets and their data capture procedures in order to determine if they are suitable for the stand-off iris recognition research. Majority of the iris recognition datasets include only frontal iris images. Even if a few datasets include off-angle iris images, the frontal and off-angle iris images are not captured at the same time. The comparison of the frontal and off-angle iris images shows not only differences in the gaze angle but also change in pupil dilation and accommodation as well. In order to isolate the effect of the gaze angle from other challenging issues including dilation and accommodation, the frontal and off-angle iris images are supposed to be captured at the same time by using two different cameras. Therefore, we developed an iris image acquisition platform by using two cameras in this work where one camera captures frontal iris image and the other one captures iris images from off-angle. Based on the comparison of Hamming distance between frontal and off-angle iris images captured with the two-camera- setup and one-camera-setup, we observed that Hamming distance in two-camera-setup is less than one-camera-setup ranging from 0.05 to 0.001. These results show that in order to have accurate results in the off-angle iris recognition research, two-camera-setup is necessary in order to distinguish the challenging issues from each other.

Sub-Camera Calibration of a Penta-Camera

NASA Astrophysics Data System (ADS)

Jacobsen, K.; Gerke, M.

2016-03-01

Penta cameras consisting of a nadir and four inclined cameras are becoming more and more popular, having the advantage of imaging also facades in built up areas from four directions. Such system cameras require a boresight calibration of the geometric relation of the cameras to each other, but also a calibration of the sub-cameras. Based on data sets of the ISPRS/EuroSDR benchmark for multi platform photogrammetry the inner orientation of the used IGI Penta DigiCAM has been analyzed. The required image coordinates of the blocks Dortmund and Zeche Zollern have been determined by Pix4Dmapper and have been independently adjusted and analyzed by program system BLUH. With 4.1 million image points in 314 images respectively 3.9 million image points in 248 images a dense matching was provided by Pix4Dmapper. With up to 19 respectively 29 images per object point the images are well connected, nevertheless the high number of images per object point are concentrated to the block centres while the inclined images outside the block centre are satisfying but not very strongly connected. This leads to very high values for the Student test (T-test) of the finally used additional parameters or in other words, additional parameters are highly significant. The estimated radial symmetric distortion of the nadir sub-camera corresponds to the laboratory calibration of IGI, but there are still radial symmetric distortions also for the inclined cameras with a size exceeding 5μm even if mentioned as negligible based on the laboratory calibration. Radial and tangential effects of the image corners are limited but still available. Remarkable angular affine systematic image errors can be seen especially in the block Zeche Zollern. Such deformations are unusual for digital matrix cameras, but it can be caused by the correlation between inner and exterior orientation if only parallel flight lines are used. With exception of the angular affinity the systematic image errors for corresponding cameras of both blocks have the same trend, but as usual for block adjustments with self calibration, they still show significant differences. Based on the very high number of image points the remaining image residuals can be safely determined by overlaying and averaging the image residuals corresponding to their image coordinates. The size of the systematic image errors, not covered by the used additional parameters, is in the range of a square mean of 0.1 pixels corresponding to 0.6μm. They are not the same for both blocks, but show some similarities for corresponding cameras. In general the bundle block adjustment with a satisfying set of additional parameters, checked by remaining systematic errors, is required for use of the whole geometric potential of the penta camera. Especially for object points on facades, often only in two images and taken with a limited base length, the correct handling of systematic image errors is important. At least in the analyzed data sets the self calibration of sub-cameras by bundle block adjustment suffers from the correlation of the inner to the exterior calibration due to missing crossing flight directions. As usual, the systematic image errors differ from block to block even without the influence of the correlation to the exterior orientation.

Hyperspectral imaging polarimeter in the infrared

NASA Astrophysics Data System (ADS)

Jensen, Gary L.; Peterson, James Q.

1998-11-01

The Space Dynamics Laboratory at Utah State University is building an infrared Hyperspectral Imaging Polarimeter (HIP). Designed for high spatial and spectral resolution polarimetry of backscattered sunlight from cloud tops in the 2.7 micrometer water band, it will fly aboard the Flying Infrared Signatures Technology Aircraft (FISTA), an Air Force KC-135. It is a proof-of-concept sensor, combining hyperspectral pushbroom imaging with high speed, solid state polarimetry, using as many off-the-shelf components as possible, and utilizing an optical breadboard design for rapid prototyping. It is based around a 256 X 320 window selectable InSb camera, a solid-state Ferro-electric Liquid Crystal (FLC) polarimeter, and a transmissive diffraction grating.

Simultaneous planar measurements of soot structure and velocity fields in a turbulent lifted jet flame at 3 kHz

NASA Astrophysics Data System (ADS)

Köhler, M.; Boxx, I.; Geigle, K. P.; Meier, W.

2011-05-01

We describe a newly developed combustion diagnostic for the simultaneous planar imaging of soot structure and velocity fields in a highly sooting, lifted turbulent jet flame at 3000 frames per second, or two orders of magnitude faster than "conventional" laser imaging systems. This diagnostic uses short pulse duration (8 ns), frequency-doubled, diode-pumped solid state (DPSS) lasers to excite laser-induced incandescence (LII) at 3 kHz, which is then imaged onto a high framerate CMOS camera. A second (dual-cavity) DPSS laser and CMOS camera form the basis of a particle image velocity (PIV) system used to acquire 2-component velocity field in the flame. The LII response curve (measured in a laminar propane diffusion flame) is presented and the combined diagnostics then applied in a heavily sooting lifted turbulent jet flame. The potential challenges and rewards of application of this combined imaging technique at high speeds are discussed.

Laser line scan underwater imaging by complementary metal-oxide-semiconductor camera

NASA Astrophysics Data System (ADS)

He, Zhiyi; Luo, Meixing; Song, Xiyu; Wang, Dundong; He, Ning

2017-12-01

This work employs the complementary metal-oxide-semiconductor (CMOS) camera to acquire images in a scanning manner for laser line scan (LLS) underwater imaging to alleviate backscatter impact of seawater. Two operating features of the CMOS camera, namely the region of interest (ROI) and rolling shutter, can be utilized to perform image scan without the difficulty of translating the receiver above the target as the traditional LLS imaging systems have. By the dynamically reconfigurable ROI of an industrial CMOS camera, we evenly divided the image into five subareas along the pixel rows and then scanned them by changing the ROI region automatically under the synchronous illumination by the fun beams of the lasers. Another scanning method was explored by the rolling shutter operation of the CMOS camera. The fun beam lasers were turned on/off to illuminate the narrow zones on the target in a good correspondence to the exposure lines during the rolling procedure of the camera's electronic shutter. The frame synchronization between the image scan and the laser beam sweep may be achieved by either the strobe lighting output pulse or the external triggering pulse of the industrial camera. Comparison between the scanning and nonscanning images shows that contrast of the underwater image can be improved by our LLS imaging techniques, with higher stability and feasibility than the mechanically controlled scanning method.

Electronic camera-management system for 35-mm and 70-mm film cameras

NASA Astrophysics Data System (ADS)

Nielsen, Allan

1993-01-01

Military and commercial test facilities have been tasked with the need for increasingly sophisticated data collection and data reduction. A state-of-the-art electronic control system for high speed 35 mm and 70 mm film cameras designed to meet these tasks is described. Data collection in today's test range environment is difficult at best. The need for a completely integrated image and data collection system is mandated by the increasingly complex test environment. Instrumentation film cameras have been used on test ranges to capture images for decades. Their high frame rates coupled with exceptionally high resolution make them an essential part of any test system. In addition to documenting test events, today's camera system is required to perform many additional tasks. Data reduction to establish TSPI (time- space-position information) may be performed after a mission and is subject to all of the variables present in documenting the mission. A typical scenario would consist of multiple cameras located on tracking mounts capturing the event along with azimuth and elevation position data. Corrected data can then be reduced using each camera's time and position deltas and calculating the TSPI of the object using triangulation. An electronic camera control system designed to meet these requirements has been developed by Photo-Sonics, Inc. The feedback received from test technicians at range facilities throughout the world led Photo-Sonics to design the features of this control system. These prominent new features include: a comprehensive safety management system, full local or remote operation, frame rate accuracy of less than 0.005 percent, and phase locking capability to Irig-B. In fact, Irig-B phase lock operation of multiple cameras can reduce the time-distance delta of a test object traveling at mach-1 to less than one inch during data reduction.

New opportunities for quality enhancing of images captured by passive THz camera

NASA Astrophysics Data System (ADS)

Trofimov, Vyacheslav A.; Trofimov, Vladislav V.

2014-10-01

As it is well-known, the passive THz camera allows seeing concealed object without contact with a person and this camera is non-dangerous for a person. Obviously, efficiency of using the passive THz camera depends on its temperature resolution. This characteristic specifies possibilities of the detection for concealed object: minimal size of the object; maximal distance of the detection; image quality. Computer processing of the THz image may lead to many times improving of the image quality without any additional engineering efforts. Therefore, developing of modern computer code for its application to THz images is urgent problem. Using appropriate new methods one may expect such temperature resolution which will allow to see banknote in pocket of a person without any real contact. Modern algorithms for computer processing of THz images allow also to see object inside the human body using a temperature trace on the human skin. This circumstance enhances essentially opportunity of passive THz camera applications for counterterrorism problems. We demonstrate opportunities, achieved at present time, for the detection both of concealed objects and of clothes components due to using of computer processing of images captured by passive THz cameras, manufactured by various companies. Another important result discussed in the paper consists in observation of both THz radiation emitted by incandescent lamp and image reflected from ceramic floorplate. We consider images produced by THz passive cameras manufactured by Microsemi Corp., and ThruVision Corp., and Capital Normal University (Beijing, China). All algorithms for computer processing of the THz images under consideration in this paper were developed by Russian part of author list. Keywords: THz wave, passive imaging camera, computer processing, security screening, concealed and forbidden objects, reflected image, hand seeing, banknote seeing, ceramic floorplate, incandescent lamp.

How Many Pixels Does It Take to Make a Good 4"×6" Print? Pixel Count Wars Revisited

NASA Astrophysics Data System (ADS)

Kriss, Michael A.

Digital still cameras emerged following the introduction of the Sony Mavica analog prototype camera in 1981. These early cameras produced poor image quality and did not challenge film cameras for overall quality. By 1995 digital still cameras in expensive SLR formats had 6 mega-pixels and produced high quality images (with significant image processing). In 2005 significant improvement in image quality was apparent and lower prices for digital still cameras (DSCs) started a rapid decline in film usage and film camera sells. By 2010 film usage was mostly limited to professionals and the motion picture industry. The rise of DSCs was marked by a “pixel war” where the driving feature of the cameras was the pixel count where even moderate cost, ˜120, DSCs would have 14 mega-pixels. The improvement of CMOS technology pushed this trend of lower prices and higher pixel counts. Only the single lens reflex cameras had large sensors and large pixels. The drive for smaller pixels hurt the quality aspects of the final image (sharpness, noise, speed, and exposure latitude). Only today are camera manufactures starting to reverse their course and producing DSCs with larger sensors and pixels. This paper will explore why larger pixels and sensors are key to the future of DSCs.

Light field rendering with omni-directional camera

NASA Astrophysics Data System (ADS)

Todoroki, Hiroshi; Saito, Hideo

2003-06-01

This paper presents an approach to capture visual appearance of a real environment such as an interior of a room. We propose the method for generating arbitrary viewpoint images by building light field with the omni-directional camera, which can capture the wide circumferences. Omni-directional camera used in this technique is a special camera with the hyperbolic mirror in the upper part of a camera, so that we can capture luminosity in the environment in the range of 360 degree of circumferences in one image. We apply the light field method, which is one technique of Image-Based-Rendering(IBR), for generating the arbitrary viewpoint images. The light field is a kind of the database that records the luminosity information in the object space. We employ the omni-directional camera for constructing the light field, so that we can collect many view direction images in the light field. Thus our method allows the user to explore the wide scene, that can acheive realistic representation of virtual enviroment. For demonstating the proposed method, we capture image sequence in our lab's interior environment with an omni-directional camera, and succesfully generate arbitray viewpoint images for virual tour of the environment.

A telephoto camera system with shooting direction control by gaze detection

NASA Astrophysics Data System (ADS)

Teraya, Daiki; Hachisu, Takumi; Yendo, Tomohiro

2015-05-01

For safe driving, it is important for driver to check traffic conditions such as traffic lights, or traffic signs as early as soon. If on-vehicle camera takes image of important objects to understand traffic conditions from long distance and shows these to driver, driver can understand traffic conditions earlier. To take image of long distance objects clearly, the focal length of camera must be long. When the focal length is long, on-vehicle camera doesn't have enough field of view to check traffic conditions. Therefore, in order to get necessary images from long distance, camera must have long-focal length and controllability of shooting direction. In previous study, driver indicates shooting direction on displayed image taken by a wide-angle camera, a direction controllable camera takes telescopic image, and displays these to driver. However, driver uses a touch panel to indicate the shooting direction in previous study. It is cause of disturb driving. So, we propose a telephoto camera system for driving support whose shooting direction is controlled by driver's gaze to avoid disturbing drive. This proposed system is composed of a gaze detector and an active telephoto camera whose shooting direction is controlled. We adopt non-wear detecting method to avoid hindrance to drive. The gaze detector measures driver's gaze by image processing. The shooting direction of the active telephoto camera is controlled by galvanometer scanners and the direction can be switched within a few milliseconds. We confirmed that the proposed system takes images of gazing straight ahead of subject by experiments.

Application of single-image camera calibration for ultrasound augmented laparoscopic visualization

NASA Astrophysics Data System (ADS)

Liu, Xinyang; Su, He; Kang, Sukryool; Kane, Timothy D.; Shekhar, Raj

2015-03-01

Accurate calibration of laparoscopic cameras is essential for enabling many surgical visualization and navigation technologies such as the ultrasound-augmented visualization system that we have developed for laparoscopic surgery. In addition to accuracy and robustness, there is a practical need for a fast and easy camera calibration method that can be performed on demand in the operating room (OR). Conventional camera calibration methods are not suitable for the OR use because they are lengthy and tedious. They require acquisition of multiple images of a target pattern in its entirety to produce satisfactory result. In this work, we evaluated the performance of a single-image camera calibration tool (rdCalib; Percieve3D, Coimbra, Portugal) featuring automatic detection of corner points in the image, whether partial or complete, of a custom target pattern. Intrinsic camera parameters of a 5-mm and a 10-mm standard Stryker® laparoscopes obtained using rdCalib and the well-accepted OpenCV camera calibration method were compared. Target registration error (TRE) as a measure of camera calibration accuracy for our optical tracking-based AR system was also compared between the two calibration methods. Based on our experiments, the single-image camera calibration yields consistent and accurate results (mean TRE = 1.18 ± 0.35 mm for the 5-mm scope and mean TRE = 1.13 ± 0.32 mm for the 10-mm scope), which are comparable to the results obtained using the OpenCV method with 30 images. The new single-image camera calibration method is promising to be applied to our augmented reality visualization system for laparoscopic surgery.

Application of single-image camera calibration for ultrasound augmented laparoscopic visualization

PubMed Central

Liu, Xinyang; Su, He; Kang, Sukryool; Kane, Timothy D.; Shekhar, Raj

2017-01-01

Accurate calibration of laparoscopic cameras is essential for enabling many surgical visualization and navigation technologies such as the ultrasound-augmented visualization system that we have developed for laparoscopic surgery. In addition to accuracy and robustness, there is a practical need for a fast and easy camera calibration method that can be performed on demand in the operating room (OR). Conventional camera calibration methods are not suitable for the OR use because they are lengthy and tedious. They require acquisition of multiple images of a target pattern in its entirety to produce satisfactory result. In this work, we evaluated the performance of a single-image camera calibration tool (rdCalib; Percieve3D, Coimbra, Portugal) featuring automatic detection of corner points in the image, whether partial or complete, of a custom target pattern. Intrinsic camera parameters of a 5-mm and a 10-mm standard Stryker® laparoscopes obtained using rdCalib and the well-accepted OpenCV camera calibration method were compared. Target registration error (TRE) as a measure of camera calibration accuracy for our optical tracking-based AR system was also compared between the two calibration methods. Based on our experiments, the single-image camera calibration yields consistent and accurate results (mean TRE = 1.18 ± 0.35 mm for the 5-mm scope and mean TRE = 1.13 ± 0.32 mm for the 10-mm scope), which are comparable to the results obtained using the OpenCV method with 30 images. The new single-image camera calibration method is promising to be applied to our augmented reality visualization system for laparoscopic surgery. PMID:28943703

Application of single-image camera calibration for ultrasound augmented laparoscopic visualization.

PubMed

Liu, Xinyang; Su, He; Kang, Sukryool; Kane, Timothy D; Shekhar, Raj

2015-03-01

Accurate calibration of laparoscopic cameras is essential for enabling many surgical visualization and navigation technologies such as the ultrasound-augmented visualization system that we have developed for laparoscopic surgery. In addition to accuracy and robustness, there is a practical need for a fast and easy camera calibration method that can be performed on demand in the operating room (OR). Conventional camera calibration methods are not suitable for the OR use because they are lengthy and tedious. They require acquisition of multiple images of a target pattern in its entirety to produce satisfactory result. In this work, we evaluated the performance of a single-image camera calibration tool ( rdCalib ; Percieve3D, Coimbra, Portugal) featuring automatic detection of corner points in the image, whether partial or complete, of a custom target pattern. Intrinsic camera parameters of a 5-mm and a 10-mm standard Stryker ® laparoscopes obtained using rdCalib and the well-accepted OpenCV camera calibration method were compared. Target registration error (TRE) as a measure of camera calibration accuracy for our optical tracking-based AR system was also compared between the two calibration methods. Based on our experiments, the single-image camera calibration yields consistent and accurate results (mean TRE = 1.18 ± 0.35 mm for the 5-mm scope and mean TRE = 1.13 ± 0.32 mm for the 10-mm scope), which are comparable to the results obtained using the OpenCV method with 30 images. The new single-image camera calibration method is promising to be applied to our augmented reality visualization system for laparoscopic surgery.

Depth estimation and camera calibration of a focused plenoptic camera for visual odometry

NASA Astrophysics Data System (ADS)

Zeller, Niclas; Quint, Franz; Stilla, Uwe

2016-08-01

This paper presents new and improved methods of depth estimation and camera calibration for visual odometry with a focused plenoptic camera. For depth estimation we adapt an algorithm previously used in structure-from-motion approaches to work with images of a focused plenoptic camera. In the raw image of a plenoptic camera, scene patches are recorded in several micro-images under slightly different angles. This leads to a multi-view stereo-problem. To reduce the complexity, we divide this into multiple binocular stereo problems. For each pixel with sufficient gradient we estimate a virtual (uncalibrated) depth based on local intensity error minimization. The estimated depth is characterized by the variance of the estimate and is subsequently updated with the estimates from other micro-images. Updating is performed in a Kalman-like fashion. The result of depth estimation in a single image of the plenoptic camera is a probabilistic depth map, where each depth pixel consists of an estimated virtual depth and a corresponding variance. Since the resulting image of the plenoptic camera contains two plains: the optical image and the depth map, camera calibration is divided into two separate sub-problems. The optical path is calibrated based on a traditional calibration method. For calibrating the depth map we introduce two novel model based methods, which define the relation of the virtual depth, which has been estimated based on the light-field image, and the metric object distance. These two methods are compared to a well known curve fitting approach. Both model based methods show significant advantages compared to the curve fitting method. For visual odometry we fuse the probabilistic depth map gained from one shot of the plenoptic camera with the depth data gained by finding stereo correspondences between subsequent synthesized intensity images of the plenoptic camera. These images can be synthesized totally focused and thus finding stereo correspondences is enhanced. In contrast to monocular visual odometry approaches, due to the calibration of the individual depth maps, the scale of the scene can be observed. Furthermore, due to the light-field information better tracking capabilities compared to the monocular case can be expected. As result, the depth information gained by the plenoptic camera based visual odometry algorithm proposed in this paper has superior accuracy and reliability compared to the depth estimated from a single light-field image.

High-Resolution Mars Camera Test Image of Moon Infrared

NASA Image and Video Library

2005-09-13

This crescent view of Earth Moon in infrared wavelengths comes from a camera test by NASA Mars Reconnaissance Orbiter spacecraft on its way to Mars. This image was taken by taken by the High Resolution Imaging Science Experiment camera Sept. 8, 2005.

Design of a MATLAB(registered trademark) Image Comparison and Analysis Tool for Augmentation of the Results of the Ann Arbor Distortion Test

DTIC Science & Technology

2016-06-25

The equipment used in this procedure includes: Ann Arbor distortion tester with 50-line grating reticule, IQeye 720 digital video camera with 12...and import them into MATLAB. In order to digitally capture images of the distortion in an optical sample, an IQeye 720 video camera with a 12... video camera and Ann Arbor distortion tester. Figure 8. Computer interface for capturing images seen by IQeye 720 camera. Once an image was

Heterogeneous Vision Data Fusion for Independently Moving Cameras

DTIC Science & Technology

2010-03-01

target detection , tracking , and identification over a large terrain. The goal of the project is to investigate and evaluate the existing image...fusion algorithms, develop new real-time algorithms for Category-II image fusion, and apply these algorithms in moving target detection and tracking . The...moving target detection and classification. 15. SUBJECT TERMS Image Fusion, Target Detection , Moving Cameras, IR Camera, EO Camera 16. SECURITY

Operation and Performance of the Mars Exploration Rover Imaging System on the Martian Surface

NASA Technical Reports Server (NTRS)

Maki, Justin N.; Litwin, Todd; Herkenhoff, Ken

2005-01-01

This slide presentation details the Mars Exploration Rover (MER) imaging system. Over 144,000 images have been gathered from all Mars Missions, with 83.5% of them being gathered by MER. Each Rover has 9 cameras (Navcam, front and rear Hazcam, Pancam, Microscopic Image, Descent Camera, Engineering Camera, Science Camera) and produces 1024 x 1024 (1 Megapixel) images in the same format. All onboard image processing code is implemented in flight software and includes extensive processing capabilities such as autoexposure, flat field correction, image orientation, thumbnail generation, subframing, and image compression. Ground image processing is done at the Jet Propulsion Laboratory's Multimission Image Processing Laboratory using Video Image Communication and Retrieval (VICAR) while stereo processing (left/right pairs) is provided for raw image, radiometric correction; solar energy maps,triangulation (Cartesian 3-spaces) and slope maps.

Blinded evaluation of the effects of high definition and magnification on perceived image quality in laryngeal imaging.

PubMed

Otto, Kristen J; Hapner, Edie R; Baker, Michael; Johns, Michael M

2006-02-01

Advances in commercial video technology have improved office-based laryngeal imaging. This study investigates the perceived image quality of a true high-definition (HD) video camera and the effect of magnification on laryngeal videostroboscopy. We performed a prospective, dual-armed, single-blinded analysis of a standard laryngeal videostroboscopic examination comparing 3 separate add-on camera systems: a 1-chip charge-coupled device (CCD) camera, a 3-chip CCD camera, and a true 720p (progressive scan) HD camera. Displayed images were controlled for magnification and image size (20-inch [50-cm] display, red-green-blue, and S-video cable for 1-chip and 3-chip cameras; digital visual interface cable and HD monitor for HD camera). Ten blinded observers were then asked to rate the following 5 items on a 0-to-100 visual analog scale: resolution, color, ability to see vocal fold vibration, sense of depth perception, and clarity of blood vessels. Eight unblinded observers were then asked to rate the difference in perceived resolution and clarity of laryngeal examination images when displayed on a 10-inch (25-cm) monitor versus a 42-inch (105-cm) monitor. A visual analog scale was used. These monitors were controlled for actual resolution capacity. For each item evaluated, randomized block design analysis demonstrated that the 3-chip camera scored significantly better than the 1-chip camera (p < .05). For the categories of color and blood vessel discrimination, the 3-chip camera scored significantly better than the HD camera (p < .05). For magnification alone, observers rated the 42-inch monitor statistically better than the 10-inch monitor. The expense of new medical technology must be judged against its added value. This study suggests that HD laryngeal imaging may not add significant value over currently available video systems, in perceived image quality, when a small monitor is used. Although differences in clarity between standard and HD cameras may not be readily apparent on small displays, a large display size coupled with HD technology may impart improved diagnosis of subtle vocal fold lesions and vibratory anomalies.

Full-frame, high-speed 3D shape and deformation measurements using stereo-digital image correlation and a single color high-speed camera

NASA Astrophysics Data System (ADS)

Yu, Liping; Pan, Bing

2017-08-01

Full-frame, high-speed 3D shape and deformation measurement using stereo-digital image correlation (stereo-DIC) technique and a single high-speed color camera is proposed. With the aid of a skillfully designed pseudo stereo-imaging apparatus, color images of a test object surface, composed of blue and red channel images from two different optical paths, are recorded by a high-speed color CMOS camera. The recorded color images can be separated into red and blue channel sub-images using a simple but effective color crosstalk correction method. These separated blue and red channel sub-images are processed by regular stereo-DIC method to retrieve full-field 3D shape and deformation on the test object surface. Compared with existing two-camera high-speed stereo-DIC or four-mirror-adapter-assisted singe-camera high-speed stereo-DIC, the proposed single-camera high-speed stereo-DIC technique offers prominent advantages of full-frame measurements using a single high-speed camera but without sacrificing its spatial resolution. Two real experiments, including shape measurement of a curved surface and vibration measurement of a Chinese double-side drum, demonstrated the effectiveness and accuracy of the proposed technique.

Line following using a two camera guidance system for a mobile robot

NASA Astrophysics Data System (ADS)

Samu, Tayib; Kelkar, Nikhal; Perdue, David; Ruthemeyer, Michael A.; Matthews, Bradley O.; Hall, Ernest L.

1996-10-01

Automated unmanned guided vehicles have many potential applications in manufacturing, medicine, space and defense. A mobile robot has been designed for the 1996 Automated Unmanned Vehicle Society competition which was held in Orlando, Florida on July 15, 1996. The competition required the vehicle to follow solid and dashed lines around an approximately 800 ft. path while avoiding obstacles, overcoming terrain changes such as inclines and sand traps, and attempting to maximize speed. The purpose of this paper is to describe the algorithm developed for the line following. The line following algorithm images two windows and locates their centroid and with the knowledge that the points are on the ground plane, a mathematical and geometrical relationship between the image coordinates of the points and their corresponding ground coordinates are established. The angle of the line and minimum distance from the robot centroid are then calculated and used in the steering control. Two cameras are mounted on the robot with a camera on each side. One camera guides the robot and when it loses track of the line on its side, the robot control system automatically switches to the other camera. The test bed system has provided an educational experience for all involved and permits understanding and extending the state of the art in autonomous vehicle design.

Research into a Single-aperture Light Field Camera System to Obtain Passive Ground-based 3D Imagery of LEO Objects

NASA Astrophysics Data System (ADS)

Bechis, K.; Pitruzzello, A.

2014-09-01

This presentation describes our ongoing research into using a ground-based light field camera to obtain passive, single-aperture 3D imagery of LEO objects. Light field cameras are an emerging and rapidly evolving technology for passive 3D imaging with a single optical sensor. The cameras use an array of lenslets placed in front of the camera focal plane, which provides angle of arrival information for light rays originating from across the target, allowing range to target and 3D image to be obtained from a single image using monocular optics. The technology, which has been commercially available for less than four years, has the potential to replace dual-sensor systems such as stereo cameras, dual radar-optical systems, and optical-LIDAR fused systems, thus reducing size, weight, cost, and complexity. We have developed a prototype system for passive ranging and 3D imaging using a commercial light field camera and custom light field image processing algorithms. Our light field camera system has been demonstrated for ground-target surveillance and threat detection applications, and this paper presents results of our research thus far into applying this technology to the 3D imaging of LEO objects. The prototype 3D imaging camera system developed by Northrop Grumman uses a Raytrix R5 C2GigE light field camera connected to a Windows computer with an nVidia graphics processing unit (GPU). The system has a frame rate of 30 Hz, and a software control interface allows for automated camera triggering and light field image acquisition to disk. Custom image processing software then performs the following steps: (1) image refocusing, (2) change detection, (3) range finding, and (4) 3D reconstruction. In Step (1), a series of 2D images are generated from each light field image; the 2D images can be refocused at up to 100 different depths. Currently, steps (1) through (3) are automated, while step (4) requires some user interaction. A key requirement for light field camera operation is that the target must be within the near-field (Fraunhofer distance) of the collecting optics. For example, in visible light the near-field of a 1-m telescope extends out to about 3,500 km, while the near-field of the AEOS telescope extends out over 46,000 km. For our initial proof of concept, we have integrated our light field camera with a 14-inch Meade LX600 advanced coma-free telescope, to image various surrogate ground targets at up to tens of kilometers range. Our experiments with the 14-inch telescope have assessed factors and requirements that are traceable and scalable to a larger-aperture system that would have the near-field distance needed to obtain 3D images of LEO objects. The next step would be to integrate a light field camera with a 1-m or larger telescope and evaluate its 3D imaging capability against LEO objects. 3D imaging of LEO space objects with light field camera technology can potentially provide a valuable new tool for space situational awareness, especially for those situations where laser or radar illumination of the target objects is not feasible.

An image compression algorithm for a high-resolution digital still camera

NASA Technical Reports Server (NTRS)

Nerheim, Rosalee

1989-01-01

The Electronic Still Camera (ESC) project will provide for the capture and transmission of high-quality images without the use of film. The image quality will be superior to video and will approach the quality of 35mm film. The camera, which will have the same general shape and handling as a 35mm camera, will be able to send images to earth in near real-time. Images will be stored in computer memory (RAM) in removable cartridges readable by a computer. To save storage space, the image will be compressed and reconstructed at the time of viewing. Both lossless and loss-y image compression algorithms are studied, described, and compared.

Structure-From for Calibration of a Vehicle Camera System with Non-Overlapping Fields-Of in AN Urban Environment

NASA Astrophysics Data System (ADS)

Hanel, A.; Stilla, U.

2017-05-01

Vehicle environment cameras observing traffic participants in the area around a car and interior cameras observing the car driver are important data sources for driver intention recognition algorithms. To combine information from both camera groups, a camera system calibration can be performed. Typically, there is no overlapping field-of-view between environment and interior cameras. Often no marked reference points are available in environments, which are a large enough to cover a car for the system calibration. In this contribution, a calibration method for a vehicle camera system with non-overlapping camera groups in an urban environment is described. A-priori images of an urban calibration environment taken with an external camera are processed with the structure-frommotion method to obtain an environment point cloud. Images of the vehicle interior, taken also with an external camera, are processed to obtain an interior point cloud. Both point clouds are tied to each other with images of both image sets showing the same real-world objects. The point clouds are transformed into a self-defined vehicle coordinate system describing the vehicle movement. On demand, videos can be recorded with the vehicle cameras in a calibration drive. Poses of vehicle environment cameras and interior cameras are estimated separately using ground control points from the respective point cloud. All poses of a vehicle camera estimated for different video frames are optimized in a bundle adjustment. In an experiment, a point cloud is created from images of an underground car park, as well as a point cloud of the interior of a Volkswagen test car is created. Videos of two environment and one interior cameras are recorded. Results show, that the vehicle camera poses are estimated successfully especially when the car is not moving. Position standard deviations in the centimeter range can be achieved for all vehicle cameras. Relative distances between the vehicle cameras deviate between one and ten centimeters from tachymeter reference measurements.

The effect of microchannel plate gain depression on PAPA photon counting cameras

NASA Astrophysics Data System (ADS)

Sams, Bruce J., III

1991-03-01

PAPA (precision analog photon address) cameras are photon counting imagers which employ microchannel plates (MCPs) for image intensification. They have been used extensively in astronomical speckle imaging. The PAPA camera can produce artifacts when light incident on its MCP is highly concentrated. The effect is exacerbated by adjusting the strobe detection level too low, so that the camera accepts very small MCP pulses. The artifacts can occur even at low total count rates if the image has highly a concentrated bright spot. This paper describes how to optimize PAPA camera electronics, and describes six techniques which can avoid or minimize addressing errors.

Multi-focused microlens array optimization and light field imaging study based on Monte Carlo method.

PubMed

Li, Tian-Jiao; Li, Sai; Yuan, Yuan; Liu, Yu-Dong; Xu, Chuan-Long; Shuai, Yong; Tan, He-Ping

2017-04-03

Plenoptic cameras are used for capturing flames in studies of high-temperature phenomena. However, simulations of plenoptic camera models can be used prior to the experiment improve experimental efficiency and reduce cost. In this work, microlens arrays, which are based on the established light field camera model, are optimized into a hexagonal structure with three types of microlenses. With this improved plenoptic camera model, light field imaging of static objects and flame are simulated using the calibrated parameters of the Raytrix camera (R29). The optimized models improve the image resolution, imaging screen utilization, and shooting range of depth of field.

Extreme ultra-violet movie camera for imaging microsecond time scale magnetic reconnection

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chai, Kil-Byoung; Bellan, Paul M.

2013-12-15

An ultra-fast extreme ultra-violet (EUV) movie camera has been developed for imaging magnetic reconnection in the Caltech spheromak/astrophysical jet experiment. The camera consists of a broadband Mo:Si multilayer mirror, a fast decaying YAG:Ce scintillator, a visible light block, and a high-speed visible light CCD camera. The camera can capture EUV images as fast as 3.3 × 10{sup 6} frames per second with 0.5 cm spatial resolution. The spectral range is from 20 eV to 60 eV. EUV images reveal strong, transient, highly localized bursts of EUV radiation when magnetic reconnection occurs.

Space-variant restoration of images degraded by camera motion blur.

PubMed

Sorel, Michal; Flusser, Jan

2008-02-01

We examine the problem of restoration from multiple images degraded by camera motion blur. We consider scenes with significant depth variations resulting in space-variant blur. The proposed algorithm can be applied if the camera moves along an arbitrary curve parallel to the image plane, without any rotations. The knowledge of camera trajectory and camera parameters is not necessary. At the input, the user selects a region where depth variations are negligible. The algorithm belongs to the group of variational methods that estimate simultaneously a sharp image and a depth map, based on the minimization of a cost functional. To initialize the minimization, it uses an auxiliary window-based depth estimation algorithm. Feasibility of the algorithm is demonstrated by three experiments with real images.

Method used to test the imaging consistency of binocular camera's left-right optical system

NASA Astrophysics Data System (ADS)

Liu, Meiying; Wang, Hu; Liu, Jie; Xue, Yaoke; Yang, Shaodong; Zhao, Hui

2016-09-01

To binocular camera, the consistency of optical parameters of the left and the right optical system is an important factor that will influence the overall imaging consistency. In conventional testing procedure of optical system, there lacks specifications suitable for evaluating imaging consistency. In this paper, considering the special requirements of binocular optical imaging system, a method used to measure the imaging consistency of binocular camera is presented. Based on this method, a measurement system which is composed of an integrating sphere, a rotary table and a CMOS camera has been established. First, let the left and the right optical system capture images in normal exposure time under the same condition. Second, a contour image is obtained based on the multiple threshold segmentation result and the boundary is determined using the slope of contour lines near the pseudo-contour line. Third, the constraint of gray level based on the corresponding coordinates of left-right images is established and the imaging consistency could be evaluated through standard deviation σ of the imaging grayscale difference D (x, y) between the left and right optical system. The experiments demonstrate that the method is suitable for carrying out the imaging consistency testing for binocular camera. When the standard deviation 3σ distribution of imaging gray difference D (x, y) between the left and right optical system of the binocular camera does not exceed 5%, it is believed that the design requirements have been achieved. This method could be used effectively and paves the way for the imaging consistency testing of the binocular camera.

From a Million Miles Away, NASA Camera Shows Moon Crossing Face of Earth

NASA Image and Video Library

2015-08-05

This animation still image shows the far side of the moon, illuminated by the sun, as it crosses between the DISCOVR spacecraft's Earth Polychromatic Imaging Camera (EPIC) camera and telescope, and the Earth - one million miles away. Credits: NASA/NOAA A NASA camera aboard the Deep Space Climate Observatory (DSCOVR) satellite captured a unique view of the moon as it moved in front of the sunlit side of Earth last month. The series of test images shows the fully illuminated “dark side” of the moon that is never visible from Earth. The images were captured by NASA’s Earth Polychromatic Imaging Camera (EPIC), a four megapixel CCD camera and telescope on the DSCOVR satellite orbiting 1 million miles from Earth. From its position between the sun and Earth, DSCOVR conducts its primary mission of real-time solar wind monitoring for the National Oceanic and Atmospheric Administration (NOAA).

Imaging of breast cancer with mid- and long-wave infrared camera.

PubMed

Joro, R; Lääperi, A-L; Dastidar, P; Soimakallio, S; Kuukasjärvi, T; Toivonen, T; Saaristo, R; Järvenpää, R

2008-01-01

In this novel study the breasts of 15 women with palpable breast cancer were preoperatively imaged with three technically different infrared (IR) cameras - micro bolometer (MB), quantum well (QWIP) and photo voltaic (PV) - to compare their ability to differentiate breast cancer from normal tissue. The IR images were processed, the data for frequency analysis were collected from dynamic IR images by pixel-based analysis and from each image selectively windowed regional analysis was carried out, based on angiogenesis and nitric oxide production of cancer tissue causing vasomotor and cardiogenic frequency differences compared to normal tissue. Our results show that the GaAs QWIP camera and the InSb PV camera demonstrate the frequency difference between normal and cancerous breast tissue; the PV camera more clearly. With selected image processing operations more detailed frequency analyses could be applied to the suspicious area. The MB camera was not suitable for tissue differentiation, as the difference between noise and effective signal was unsatisfactory.

The Panoramic Camera (PanCam) Instrument for the ESA ExoMars Rover

NASA Astrophysics Data System (ADS)

Griffiths, A.; Coates, A.; Jaumann, R.; Michaelis, H.; Paar, G.; Barnes, D.; Josset, J.

The recently approved ExoMars rover is the first element of the ESA Aurora programme and is slated to deliver the Pasteur exobiology payload to Mars by 2013. The 0.7 kg Panoramic Camera will provide multispectral stereo images with 65° field-of- view (1.1 mrad/pixel) and high resolution (85 µrad/pixel) monoscopic "zoom" images with 5° field-of-view. The stereo Wide Angle Cameras (WAC) are based on Beagle 2 Stereo Camera System heritage. The Panoramic Camera instrument is designed to fulfil the digital terrain mapping requirements of the mission as well as providing multispectral geological imaging, colour and stereo panoramic images, solar images for water vapour abundance and dust optical depth measurements and to observe retrieved subsurface samples before ingestion into the rest of the Pasteur payload. Additionally the High Resolution Camera (HRC) can be used for high resolution imaging of interesting targets detected in the WAC panoramas and of inaccessible locations on crater or valley walls.

Webcam network and image database for studies of phenological changes of vegetation and snow cover in Finland, image time series from 2014 to 2016

NASA Astrophysics Data System (ADS)

Peltoniemi, Mikko; Aurela, Mika; Böttcher, Kristin; Kolari, Pasi; Loehr, John; Karhu, Jouni; Linkosalmi, Maiju; Melih Tanis, Cemal; Tuovinen, Juha-Pekka; Nadir Arslan, Ali

2018-01-01

In recent years, monitoring of the status of ecosystems using low-cost web (IP) or time lapse cameras has received wide interest. With broad spatial coverage and high temporal resolution, networked cameras can provide information about snow cover and vegetation status, serve as ground truths to Earth observations and be useful for gap-filling of cloudy areas in Earth observation time series. Networked cameras can also play an important role in supplementing laborious phenological field surveys and citizen science projects, which also suffer from observer-dependent observation bias. We established a network of digital surveillance cameras for automated monitoring of phenological activity of vegetation and snow cover in the boreal ecosystems of Finland. Cameras were mounted at 14 sites, each site having 1-3 cameras. Here, we document the network, basic camera information and access to images in the permanent data repository (http://www.zenodo.org/communities/phenology_camera/). Individual DOI-referenced image time series consist of half-hourly images collected between 2014 and 2016 (https://doi.org/10.5281/zenodo.1066862). Additionally, we present an example of a colour index time series derived from images from two contrasting sites.

The imaging system design of three-line LMCCD mapping camera

NASA Astrophysics Data System (ADS)

Zhou, Huai-de; Liu, Jin-Guo; Wu, Xing-Xing; Lv, Shi-Liang; Zhao, Ying; Yu, Da

2011-08-01

In this paper, the authors introduced the theory about LMCCD (line-matrix CCD) mapping camera firstly. On top of the introduction were consists of the imaging system of LMCCD mapping camera. Secondly, some pivotal designs which were Introduced about the imaging system, such as the design of focal plane module, the video signal's procession, the controller's design of the imaging system, synchronous photography about forward and nadir and backward camera and the nadir camera of line-matrix CCD. At last, the test results of LMCCD mapping camera imaging system were introduced. The results as following: the precision of synchronous photography about forward and nadir and backward camera is better than 4 ns and the nadir camera of line-matrix CCD is better than 4 ns too; the photography interval of line-matrix CCD of the nadir camera can satisfy the butter requirements of LMCCD focal plane module; the SNR tested in laboratory is better than 95 under typical working condition(the solar incidence degree is 30, the reflectivity of the earth's surface is 0.3) of each CCD image; the temperature of the focal plane module is controlled under 30° in a working period of 15 minutes. All of these results can satisfy the requirements about the synchronous photography, the temperature control of focal plane module and SNR, Which give the guarantee of precision for satellite photogrammetry.

A Comparative Study of Microscopic Images Captured by a Box Type Digital Camera Versus a Standard Microscopic Photography Camera Unit

PubMed Central

Desai, Nandini J.; Gupta, B. D.; Patel, Pratik Narendrabhai

2014-01-01

Introduction: Obtaining images of slides viewed by a microscope can be invaluable for both diagnosis and teaching.They can be transferred among technologically-advanced hospitals for further consultation and evaluation. But a standard microscopic photography camera unit (MPCU)(MIPS-Microscopic Image projection System) is costly and not available in resource poor settings. The aim of our endeavour was to find a comparable and cheaper alternative method for photomicrography. Materials and Methods: We used a NIKON Coolpix S6150 camera (box type digital camera) with Olympus CH20i microscope and a fluorescent microscope for the purpose of this study. Results: We got comparable results for capturing images of light microscopy, but the results were not as satisfactory for fluorescent microscopy. Conclusion: A box type digital camera is a comparable, less expensive and convenient alternative to microscopic photography camera unit. PMID:25478350

MO-AB-206-02: Testing Gamma Cameras Based On TG177 WG Report

DOE Office of Scientific and Technical Information (OSTI.GOV)

Halama, J.

2016-06-15

This education session will cover the physics and operation principles of gamma cameras and PET scanners. The first talk will focus on PET imaging. An overview of the principles of PET imaging will be provided, including positron decay physics, and the transition from 2D to 3D imaging. More recent advances in hardware and software will be discussed, such as time-of-flight imaging, and improvements in reconstruction algorithms that provide for options such as depth-of-interaction corrections. Quantitative applications of PET will be discussed, as well as the requirements for doing accurate quantitation. Relevant performance tests will also be described. Learning Objectives: Bemore » able to describe basic physics principles of PET and operation of PET scanners. Learn about recent advances in PET scanner hardware technology. Be able to describe advances in reconstruction techniques and improvements Be able to list relevant performance tests. The second talk will focus on gamma cameras. The Nuclear Medicine subcommittee has charged a task group (TG177) to develop a report on the current state of physics testing of gamma cameras, SPECT, and SPECT/CT systems. The report makes recommendations for performance tests to be done for routine quality assurance, annual physics testing, and acceptance tests, and identifies those needed satisfy the ACR accreditation program and The Joint Commission imaging standards. The report is also intended to be used as a manual with detailed instructions on how to perform tests under widely varying conditions. Learning Objectives: At the end of the presentation members of the audience will: Be familiar with the tests recommended for routine quality assurance, annual physics testing, and acceptance tests of gamma cameras for planar imaging. Be familiar with the tests recommended for routine quality assurance, annual physics testing, and acceptance tests of SPECT systems. Be familiar with the tests of a SPECT/CT system that include the CT images for SPECT reconstructions. Become knowledgeable of items to be included in annual acceptance testing reports including CT dosimetry and PACS monitor measurements. T. Turkington, GE Healthcare.« less

Traffic Sign Recognition with Invariance to Lighting in Dual-Focal Active Camera System

NASA Astrophysics Data System (ADS)

Gu, Yanlei; Panahpour Tehrani, Mehrdad; Yendo, Tomohiro; Fujii, Toshiaki; Tanimoto, Masayuki

In this paper, we present an automatic vision-based traffic sign recognition system, which can detect and classify traffic signs at long distance under different lighting conditions. To realize this purpose, the traffic sign recognition is developed in an originally proposed dual-focal active camera system. In this system, a telephoto camera is equipped as an assistant of a wide angle camera. The telephoto camera can capture a high accuracy image for an object of interest in the view field of the wide angle camera. The image from the telephoto camera provides enough information for recognition when the accuracy of traffic sign is low from the wide angle camera. In the proposed system, the traffic sign detection and classification are processed separately for different images from the wide angle camera and telephoto camera. Besides, in order to detect traffic sign from complex background in different lighting conditions, we propose a type of color transformation which is invariant to light changing. This color transformation is conducted to highlight the pattern of traffic signs by reducing the complexity of background. Based on the color transformation, a multi-resolution detector with cascade mode is trained and used to locate traffic signs at low resolution in the image from the wide angle camera. After detection, the system actively captures a high accuracy image of each detected traffic sign by controlling the direction and exposure time of the telephoto camera based on the information from the wide angle camera. Moreover, in classification, a hierarchical classifier is constructed and used to recognize the detected traffic signs in the high accuracy image from the telephoto camera. Finally, based on the proposed system, a set of experiments in the domain of traffic sign recognition is presented. The experimental results demonstrate that the proposed system can effectively recognize traffic signs at low resolution in different lighting conditions.

Image quality enhancement method for on-orbit remote sensing cameras using invariable modulation transfer function.

PubMed

Li, Jin; Liu, Zilong

2017-07-24

Remote sensing cameras in the visible/near infrared range are essential tools in Earth-observation, deep-space exploration, and celestial navigation. Their imaging performance, i.e. image quality here, directly determines the target-observation performance of a spacecraft, and even the successful completion of a space mission. Unfortunately, the camera itself, such as a optical system, a image sensor, and a electronic system, limits the on-orbit imaging performance. Here, we demonstrate an on-orbit high-resolution imaging method based on the invariable modulation transfer function (IMTF) of cameras. The IMTF, which is stable and invariable to the changing of ground targets, atmosphere, and environment on orbit or on the ground, depending on the camera itself, is extracted using a pixel optical focal-plane (PFP). The PFP produces multiple spatial frequency targets, which are used to calculate the IMTF at different frequencies. The resulting IMTF in combination with a constrained least-squares filter compensates for the IMTF, which represents the removal of the imaging effects limited by the camera itself. This method is experimentally confirmed. Experiments on an on-orbit panchromatic camera indicate that the proposed method increases 6.5 times of the average gradient, 3.3 times of the edge intensity, and 1.56 times of the MTF value compared to the case when IMTF is not used. This opens a door to push the limitation of a camera itself, enabling high-resolution on-orbit optical imaging.

Rapid assessment of forest canopy and light regime using smartphone hemispherical photography.

PubMed

Bianchi, Simone; Cahalan, Christine; Hale, Sophie; Gibbons, James Michael

2017-12-01

Hemispherical photography (HP), implemented with cameras equipped with "fisheye" lenses, is a widely used method for describing forest canopies and light regimes. A promising technological advance is the availability of low-cost fisheye lenses for smartphone cameras. However, smartphone camera sensors cannot record a full hemisphere. We investigate whether smartphone HP is a cheaper and faster but still adequate operational alternative to traditional cameras for describing forest canopies and light regimes. We collected hemispherical pictures with both smartphone and traditional cameras in 223 forest sample points, across different overstory species and canopy densities. The smartphone image acquisition followed a faster and simpler protocol than that for the traditional camera. We automatically thresholded all images. We processed the traditional camera images for Canopy Openness (CO) and Site Factor estimation. For smartphone images, we took two pictures with different orientations per point and used two processing protocols: (i) we estimated and averaged total canopy gap from the two single pictures, and (ii) merging the two pictures together, we formed images closer to full hemispheres and estimated from them CO and Site Factors. We compared the same parameters obtained from different cameras and estimated generalized linear mixed models (GLMMs) between them. Total canopy gap estimated from the first processing protocol for smartphone pictures was on average significantly higher than CO estimated from traditional camera images, although with a consistent bias. Canopy Openness and Site Factors estimated from merged smartphone pictures of the second processing protocol were on average significantly higher than those from traditional cameras images, although with relatively little absolute differences and scatter. Smartphone HP is an acceptable alternative to HP using traditional cameras, providing similar results with a faster and cheaper methodology. Smartphone outputs can be directly used as they are for ecological studies, or converted with specific models for a better comparison to traditional cameras.

Quantifying biodiversity using digital cameras and automated image analysis.

NASA Astrophysics Data System (ADS)

Roadknight, C. M.; Rose, R. J.; Barber, M. L.; Price, M. C.; Marshall, I. W.

2009-04-01

Monitoring the effects on biodiversity of extensive grazing in complex semi-natural habitats is labour intensive. There are also concerns about the standardization of semi-quantitative data collection. We have chosen to focus initially on automating the most time consuming aspect - the image analysis. The advent of cheaper and more sophisticated digital camera technology has lead to a sudden increase in the number of habitat monitoring images and information that is being collected. We report on the use of automated trail cameras (designed for the game hunting market) to continuously capture images of grazer activity in a variety of habitats at Moor House National Nature Reserve, which is situated in the North of England at an average altitude of over 600m. Rainfall is high, and in most areas the soil consists of deep peat (1m to 3m), populated by a mix of heather, mosses and sedges. The cameras have been continuously in operation over a 6 month period, daylight images are in full colour and night images (IR flash) are black and white. We have developed artificial intelligence based methods to assist in the analysis of the large number of images collected, generating alert states for new or unusual image conditions. This paper describes the data collection techniques, outlines the quantitative and qualitative data collected and proposes online and offline systems that can reduce the manpower overheads and increase focus on important subsets in the collected data. By converting digital image data into statistical composite data it can be handled in a similar way to other biodiversity statistics thus improving the scalability of monitoring experiments. Unsupervised feature detection methods and supervised neural methods were tested and offered solutions to simplifying the process. Accurate (85 to 95%) categorization of faunal content can be obtained, requiring human intervention for only those images containing rare animals or unusual (undecidable) conditions, and enabling automatic deletion of images generated by erroneous triggering (e.g. cloud movements). This is the first step to a hierarchical image processing framework, where situation subclasses such as birds or climatic conditions can be fed into more appropriate automated or semi-automated data mining software.

Video auto stitching in multicamera surveillance system

NASA Astrophysics Data System (ADS)

He, Bin; Zhao, Gang; Liu, Qifang; Li, Yangyang

2012-01-01

This paper concerns the problem of video stitching automatically in a multi-camera surveillance system. Previous approaches have used multiple calibrated cameras for video mosaic in large scale monitoring application. In this work, we formulate video stitching as a multi-image registration and blending problem, and not all cameras are needed to be calibrated except a few selected master cameras. SURF is used to find matched pairs of image key points from different cameras, and then camera pose is estimated and refined. Homography matrix is employed to calculate overlapping pixels and finally implement boundary resample algorithm to blend images. The result of simulation demonstrates the efficiency of our method.

Video auto stitching in multicamera surveillance system

NASA Astrophysics Data System (ADS)

He, Bin; Zhao, Gang; Liu, Qifang; Li, Yangyang

2011-12-01

This paper concerns the problem of video stitching automatically in a multi-camera surveillance system. Previous approaches have used multiple calibrated cameras for video mosaic in large scale monitoring application. In this work, we formulate video stitching as a multi-image registration and blending problem, and not all cameras are needed to be calibrated except a few selected master cameras. SURF is used to find matched pairs of image key points from different cameras, and then camera pose is estimated and refined. Homography matrix is employed to calculate overlapping pixels and finally implement boundary resample algorithm to blend images. The result of simulation demonstrates the efficiency of our method.

Video monitoring in the Gadria debris flow catchment: preliminary results of large scale particle image velocimetry (LSPIV)

NASA Astrophysics Data System (ADS)

Theule, Joshua; Crema, Stefano; Comiti, Francesco; Cavalli, Marco; Marchi, Lorenzo

2015-04-01

Large scale particle image velocimetry (LSPIV) is a technique mostly used in rivers to measure two dimensional velocities from high resolution images at high frame rates. This technique still needs to be thoroughly explored in the field of debris flow studies. The Gadria debris flow monitoring catchment in Val Venosta (Italian Alps) has been equipped with four MOBOTIX M12 video cameras. Two cameras are located in a sediment trap located close to the alluvial fan apex, one looking upstream and the other looking down and more perpendicular to the flow. The third camera is in the next reach upstream from the sediment trap at a closer proximity to the flow. These three cameras are connected to a field shelter equipped with power supply and a server collecting all the monitoring data. The fourth camera is located in an active gully, the camera is activated by a rain gauge when there is one minute of rainfall. Before LSPIV can be used, the highly distorted images need to be corrected and accurate reference points need to be made. We decided to use IMGRAFT (an opensource image georectification toolbox) which can correct distorted images using reference points and camera location, and then finally rectifies the batch of images onto a DEM grid (or the DEM grid onto the image coordinates). With the orthorectified images, we used the freeware Fudaa-LSPIV (developed by EDF, IRSTEA, and DeltaCAD Company) to generate the LSPIV calculations of the flow events. Calculated velocities can easily be checked manually because of the already orthorectified images. During the monitoring program (since 2011) we recorded three debris flow events at the sediment trap area (each with very different surge dynamics). The camera in the gully was in operation in 2014 which managed to record granular flows and rockfalls, which particle tracking may be more appropriate for velocity measurements. The four cameras allows us to explore the limitations of camera distance, angle, frame rate, and image quality.

Engineering design criteria for an image intensifier/image converter camera

NASA Technical Reports Server (NTRS)

Sharpsteen, J. T.; Lund, D. L.; Stoap, L. J.; Solheim, C. D.

1976-01-01

The design, display, and evaluation of an image intensifier/image converter camera which can be utilized in various requirements of spaceshuttle experiments are described. An image intensifier tube was utilized in combination with two brassboards as power supply and used for evaluation of night photography in the field. Pictures were obtained showing field details which would have been undistinguishable to the naked eye or to an ordinary camera.

Ultra-fast framing camera tube

DOEpatents

Kalibjian, Ralph

1981-01-01

An electronic framing camera tube features focal plane image dissection and synchronized restoration of the dissected electron line images to form two-dimensional framed images. Ultra-fast framing is performed by first streaking a two-dimensional electron image across a narrow slit, thereby dissecting the two-dimensional electron image into sequential electron line images. The dissected electron line images are then restored into a framed image by a restorer deflector operated synchronously with the dissector deflector. The number of framed images on the tube's viewing screen is equal to the number of dissecting slits in the tube. The distinguishing features of this ultra-fast framing camera tube are the focal plane dissecting slits, and the synchronously-operated restorer deflector which restores the dissected electron line images into a two-dimensional framed image. The framing camera tube can produce image frames having high spatial resolution of optical events in the sub-100 picosecond range.

Remote sensing of cloud droplet size distributions in DC3 with the UMBC-LACO Rainbow Polarimetric Imager (RPI)

NASA Astrophysics Data System (ADS)

Buczkowski, S.; Martins, J.; Fernandez-Borda, R.; Cieslak, D.; Hall, J.

2013-12-01

The UMBC Rainbow Polarimetric Imager is a small form factor VIS imaging polarimeter suitable for use on a number of platforms. An optical system based on a Phillips prism with three Bayer filter color detectors, each detecting a separate polarization state, allows simultaneous detection of polarization and spectral information. A Mueller matrix-like calibration scheme corrects for polarization artifacts in the optical train and allows retrieval of the polarization state of incoming light to better than 0.5%. Coupled with wide field of view optics (~90°), RPI can capture images of cloudbows over a wide range of aircraft headings and solar zenith angles for retrieval of cloud droplet size distribution (DSD) parameters. In May-June 2012, RPI was flown in a nadir port on the NASA DC-8 during the DC3 field campaign. We will show examples of cloudbow DSD parameter retrievals from the campaign to demonstrate the efficacy of such a system to terrestrial atmospheric remote sensing. RPI image from DC3 06/15/2012 flight. Left panel is raw image from the RPI 90° camera. Middle panel is Stokes 'q' parameter retrieved from full three camera dataset. Right panel is a horizontal cut in 'q' through the glory. Both middle and right panels clearly show cloudbow features which can be fit to infer cloud DSD parameters.

a Spatio-Spectral Camera for High Resolution Hyperspectral Imaging

NASA Astrophysics Data System (ADS)

Livens, S.; Pauly, K.; Baeck, P.; Blommaert, J.; Nuyts, D.; Zender, J.; Delauré, B.

2017-08-01

Imaging with a conventional frame camera from a moving remotely piloted aircraft system (RPAS) is by design very inefficient. Less than 1 % of the flying time is used for collecting light. This unused potential can be utilized by an innovative imaging concept, the spatio-spectral camera. The core of the camera is a frame sensor with a large number of hyperspectral filters arranged on the sensor in stepwise lines. It combines the advantages of frame cameras with those of pushbroom cameras. By acquiring images in rapid succession, such a camera can collect detailed hyperspectral information, while retaining the high spatial resolution offered by the sensor. We have developed two versions of a spatio-spectral camera and used them in a variety of conditions. In this paper, we present a summary of three missions with the in-house developed COSI prototype camera (600-900 nm) in the domains of precision agriculture (fungus infection monitoring in experimental wheat plots), horticulture (crop status monitoring to evaluate irrigation management in strawberry fields) and geology (meteorite detection on a grassland field). Additionally, we describe the characteristics of the 2nd generation, commercially available ButterflEYE camera offering extended spectral range (475-925 nm), and we discuss future work.

Hydrogen peroxide plasma sterilization of a waterproof, high-definition video camera case for intraoperative imaging in veterinary surgery.

PubMed

Adin, Christopher A; Royal, Kenneth D; Moore, Brandon; Jacob, Megan

2018-06-13

To evaluate the safety and usability of a wearable, waterproof high-definition camera/case for acquisition of surgical images by sterile personnel. An in vitro study to test the efficacy of biodecontamination of camera cases. Usability for intraoperative image acquisition was assessed in clinical procedures. Two waterproof GoPro Hero4 Silver camera cases were inoculated by immersion in media containing Staphylococcus pseudointermedius or Escherichia coli at ≥5.50E+07 colony forming units/mL. Cases were biodecontaminated by manual washing and hydrogen peroxide plasma sterilization. Cultures were obtained by swab and by immersion in enrichment broth before and after each contamination/decontamination cycle (n = 4). The cameras were then applied by a surgeon in clinical procedures by using either a headband or handheld mode and were assessed for usability according to 5 user characteristics. Cultures of all poststerilization swabs were negative. One of 8 cultures was positive in enrichment broth, consistent with a low level of contamination in 1 sample. Usability of the camera was considered poor in headband mode, with limited battery life, inability to control camera functions, and lack of zoom function affecting image quality. Handheld operation of the camera by the primary surgeon improved usability, allowing close-up still and video intraoperative image acquisition. Vaporized hydrogen peroxide sterilization of this camera case was considered effective for biodecontamination. Handheld operation improved usability for intraoperative image acquisition. Vaporized hydrogen peroxide sterilization and thorough manual washing of a waterproof camera may provide cost effective intraoperative image acquisition for documentation purposes. © 2018 The American College of Veterinary Surgeons.

Selecting a digital camera for telemedicine.

PubMed

Patricoski, Chris; Ferguson, A Stewart

2009-06-01

The digital camera is an essential component of store-and-forward telemedicine (electronic consultation). There are numerous makes and models of digital cameras on the market, and selecting a suitable consumer-grade camera can be complicated. Evaluation of digital cameras includes investigating the features and analyzing image quality. Important features include the camera settings, ease of use, macro capabilities, method of image transfer, and power recharging. Consideration needs to be given to image quality, especially as it relates to color (skin tones) and detail. It is important to know the level of the photographer and the intended application. The goal is to match the characteristics of the camera with the telemedicine program requirements. In the end, selecting a digital camera is a combination of qualitative (subjective) and quantitative (objective) analysis. For the telemedicine program in Alaska in 2008, the camera evaluation and decision process resulted in a specific selection based on the criteria developed for our environment.

Advanced High-Definition Video Cameras

NASA Technical Reports Server (NTRS)

Glenn, William

2007-01-01

A product line of high-definition color video cameras, now under development, offers a superior combination of desirable characteristics, including high frame rates, high resolutions, low power consumption, and compactness. Several of the cameras feature a 3,840 2,160-pixel format with progressive scanning at 30 frames per second. The power consumption of one of these cameras is about 25 W. The size of the camera, excluding the lens assembly, is 2 by 5 by 7 in. (about 5.1 by 12.7 by 17.8 cm). The aforementioned desirable characteristics are attained at relatively low cost, largely by utilizing digital processing in advanced field-programmable gate arrays (FPGAs) to perform all of the many functions (for example, color balance and contrast adjustments) of a professional color video camera. The processing is programmed in VHDL so that application-specific integrated circuits (ASICs) can be fabricated directly from the program. ["VHDL" signifies VHSIC Hardware Description Language C, a computing language used by the United States Department of Defense for describing, designing, and simulating very-high-speed integrated circuits (VHSICs).] The image-sensor and FPGA clock frequencies in these cameras have generally been much higher than those used in video cameras designed and manufactured elsewhere. Frequently, the outputs of these cameras are converted to other video-camera formats by use of pre- and post-filters.

A system for tracking and recognizing pedestrian faces using a network of loosely coupled cameras

NASA Astrophysics Data System (ADS)

Gagnon, L.; Laliberté, F.; Foucher, S.; Branzan Albu, A.; Laurendeau, D.

2006-05-01

A face recognition module has been developed for an intelligent multi-camera video surveillance system. The module can recognize a pedestrian face in terms of six basic emotions and the neutral state. Face and facial features detection (eyes, nasal root, nose and mouth) are first performed using cascades of boosted classifiers. These features are used to normalize the pose and dimension of the face image. Gabor filters are then sampled on a regular grid covering the face image to build a facial feature vector that feeds a nearest neighbor classifier with a cosine distance similarity measure for facial expression interpretation and face model construction. A graphical user interface allows the user to adjust the module parameters.

Sky camera geometric calibration using solar observations

DOE PAGES

Urquhart, Bryan; Kurtz, Ben; Kleissl, Jan

2016-09-05

A camera model and associated automated calibration procedure for stationary daytime sky imaging cameras is presented. The specific modeling and calibration needs are motivated by remotely deployed cameras used to forecast solar power production where cameras point skyward and use 180° fisheye lenses. Sun position in the sky and on the image plane provides a simple and automated approach to calibration; special equipment or calibration patterns are not required. Sun position in the sky is modeled using a solar position algorithm (requiring latitude, longitude, altitude and time as inputs). Sun position on the image plane is detected using a simple image processing algorithm. Themore » performance evaluation focuses on the calibration of a camera employing a fisheye lens with an equisolid angle projection, but the camera model is general enough to treat most fixed focal length, central, dioptric camera systems with a photo objective lens. Calibration errors scale with the noise level of the sun position measurement in the image plane, but the calibration is robust across a large range of noise in the sun position. In conclusion, calibration performance on clear days ranged from 0.94 to 1.24 pixels root mean square error.« less

A new star tracker concept for satellite attitude determination based on a multi-purpose panoramic camera

NASA Astrophysics Data System (ADS)

Opromolla, Roberto; Fasano, Giancarmine; Rufino, Giancarlo; Grassi, Michele; Pernechele, Claudio; Dionisio, Cesare

2017-11-01

This paper presents an innovative algorithm developed for attitude determination of a space platform. The algorithm exploits images taken from a multi-purpose panoramic camera equipped with hyper-hemispheric lens and used as star tracker. The sensor architecture is also original since state-of-the-art star trackers accurately image as many stars as possible within a narrow- or medium-size field-of-view, while the considered sensor observes an extremely large portion of the celestial sphere but its observation capabilities are limited by the features of the optical system. The proposed original approach combines algorithmic concepts, like template matching and point cloud registration, inherited from the computer vision and robotic research fields, to carry out star identification. The final aim is to provide a robust and reliable initial attitude solution (lost-in-space mode), with a satisfactory accuracy level in view of the multi-purpose functionality of the sensor and considering its limitations in terms of resolution and sensitivity. Performance evaluation is carried out within a simulation environment in which the panoramic camera operation is realistically reproduced, including perturbations in the imaged star pattern. Results show that the presented algorithm is able to estimate attitude with accuracy better than 1° with a success rate around 98% evaluated by densely covering the entire space of the parameters representing the camera pointing in the inertial space.

Alternative images for perpendicular parking : a usability test of a multi-camera parking assistance system.

DOT National Transportation Integrated Search

2004-10-01

The parking assistance system evaluated consisted of four outward facing cameras whose images could be presented on a monitor on the center console. The images presented varied in the location of the virtual eye point of the camera (the height above ...

Camera artifacts in IUE spectra

NASA Technical Reports Server (NTRS)

Bruegman, O. W.; Crenshaw, D. M.

1994-01-01

This study of emission line mimicking features in the IUE cameras has produced an atlas of artifiacts in high-dispersion images with an accompanying table of prominent artifacts and a table of prominent artifacts in the raw images along with a medium image of the sky background for each IUE camera.

A low-cost dual-camera imaging system for aerial applicators

USDA-ARS?s Scientific Manuscript database

Agricultural aircraft provide a readily available remote sensing platform as low-cost and easy-to-use consumer-grade cameras are being increasingly used for aerial imaging. In this article, we report on a dual-camera imaging system we recently assembled that can capture RGB and near-infrared (NIR) i...

Left Panorama of Spirit's Landing Site

NASA Technical Reports Server (NTRS)

2004-01-01

Left Panorama of Spirit's Landing Site

This is a version of the first 3-D stereo image from the rover's navigation camera, showing only the view from the left stereo camera onboard the Mars Exploration Rover Spirit. The left and right camera images are combined to produce a 3-D image.

Effect of Clouds on Optical Imaging of the Space Shuttle During the Ascent Phase: A Statistical Analysis Based on a 3D Model

NASA Technical Reports Server (NTRS)

Short, David A.; Lane, Robert E., Jr.; Winters, Katherine A.; Madura, John T.

2004-01-01

Clouds are highly effective in obscuring optical images of the Space Shuttle taken during its ascent by ground-based and airborne tracking cameras. Because the imagery is used for quick-look and post-flight engineering analysis, the Columbia Accident Investigation Board (CAIB) recommended the return-to-flight effort include an upgrade of the imaging system to enable it to obtain at least three useful views of the Shuttle from lift-off to at least solid rocket booster (SRB) separation (NASA 2003). The lifetimes of individual cloud elements capable of obscuring optical views of the Shuttle are typically 20 minutes or less. Therefore, accurately observing and forecasting cloud obscuration over an extended network of cameras poses an unprecedented challenge for the current state of observational and modeling techniques. In addition, even the best numerical simulations based on real observations will never reach "truth." In order to quantify the risk that clouds would obscure optical imagery of the Shuttle, a 3D model to calculate probabilistic risk was developed. The model was used to estimate the ability of a network of optical imaging cameras to obtain at least N simultaneous views of the Shuttle from lift-off to SRB separation in the presence of an idealized, randomized cloud field.

Generating Stereoscopic Television Images With One Camera

NASA Technical Reports Server (NTRS)

Coan, Paul P.

1996-01-01

Straightforward technique for generating stereoscopic television images involves use of single television camera translated laterally between left- and right-eye positions. Camera acquires one of images (left- or right-eye image), and video signal from image delayed while camera translated to position where it acquires other image. Length of delay chosen so both images displayed simultaneously or as nearly simultaneously as necessary to obtain stereoscopic effect. Technique amenable to zooming in on small areas within broad scenes. Potential applications include three-dimensional viewing of geological features and meteorological events from spacecraft and aircraft, inspection of workpieces moving along conveyor belts, and aiding ground and water search-and-rescue operations. Also used to generate and display imagery for public education and general information, and possible for medical purposes.

UCXp camera imaging principle and key technologies of data post-processing

NASA Astrophysics Data System (ADS)

Yuan, Fangyan; Li, Guoqing; Zuo, Zhengli; Liu, Jianmin; Wu, Liang; Yu, Xiaoping; Zhao, Haitao

2014-03-01

The large format digital aerial camera product UCXp was introduced into the Chinese market in 2008, the image consists of 17310 columns and 11310 rows with a pixel size of 6 mm. The UCXp camera has many advantages compared with the same generation camera, with multiple lenses exposed almost at the same time and no oblique lens. The camera has a complex imaging process whose principle will be detailed in this paper. On the other hand, the UCXp image post-processing method, including data pre-processing and orthophoto production, will be emphasized in this article. Based on the data of new Beichuan County, this paper will describe the data processing and effects.

High resolution Thomson scattering system for steady-state linear plasma sources

NASA Astrophysics Data System (ADS)

Lee, K. Y.; Lee, K. I.; Kim, J. H.; Lho, T.

2018-01-01

The high resolution Thomson scattering system with 63 points along a 25 mm line measures the radial electron temperature (Te) and its density (ne) in an argon plasma. By using a DC arc source with lanthanum hexaboride (LaB6) electrode, plasmas with electron temperature of over 5 eV and densities of 1.5 × 1019 m-3 have been measured. The system uses a frequency doubled (532 nm) Nd:YAG laser with 0.25 J/pulse at 20 Hz. The scattered light is collected and sent to a triple-grating spectrometer via optical-fibers, where images are recorded by an intensified charge coupled device (ICCD) camera. Although excellent in stray-light reduction, a disadvantage comes with its relatively low optical transmission and in sampling a tiny scattering volume. Thus requires accumulating multitude of images. In order to improve photon statistics, pixel binning in the ICCD camera as well as enlarging the intermediate slit-width inside the triple-grating spectrometer has been exploited. In addition, the ICCD camera capture images at 40 Hz while the laser is at 20 Hz. This operation mode allows us to alternate between background and scattering shot images. By image subtraction, influences from the plasma background are effectively taken out. Maximum likelihood estimation that uses a parameter sweep finds best fitting parameters Te and ne with the incoherent scattering spectrum.

High resolution Thomson scattering system for steady-state linear plasma sources.

PubMed

Lee, K Y; Lee, K I; Kim, J H; Lho, T

2018-01-01

The high resolution Thomson scattering system with 63 points along a 25 mm line measures the radial electron temperature (T e ) and its density (n e ) in an argon plasma. By using a DC arc source with lanthanum hexaboride (LaB 6 ) electrode, plasmas with electron temperature of over 5 eV and densities of 1.5 × 10 19 m -3 have been measured. The system uses a frequency doubled (532 nm) Nd:YAG laser with 0.25 J/pulse at 20 Hz. The scattered light is collected and sent to a triple-grating spectrometer via optical-fibers, where images are recorded by an intensified charge coupled device (ICCD) camera. Although excellent in stray-light reduction, a disadvantage comes with its relatively low optical transmission and in sampling a tiny scattering volume. Thus requires accumulating multitude of images. In order to improve photon statistics, pixel binning in the ICCD camera as well as enlarging the intermediate slit-width inside the triple-grating spectrometer has been exploited. In addition, the ICCD camera capture images at 40 Hz while the laser is at 20 Hz. This operation mode allows us to alternate between background and scattering shot images. By image subtraction, influences from the plasma background are effectively taken out. Maximum likelihood estimation that uses a parameter sweep finds best fitting parameters T e and n e with the incoherent scattering spectrum.

Visual object recognition for mobile tourist information systems

NASA Astrophysics Data System (ADS)

Paletta, Lucas; Fritz, Gerald; Seifert, Christin; Luley, Patrick; Almer, Alexander

2005-03-01

We describe a mobile vision system that is capable of automated object identification using images captured from a PDA or a camera phone. We present a solution for the enabling technology of outdoors vision based object recognition that will extend state-of-the-art location and context aware services towards object based awareness in urban environments. In the proposed application scenario, tourist pedestrians are equipped with GPS, W-LAN and a camera attached to a PDA or a camera phone. They are interested whether their field of view contains tourist sights that would point to more detailed information. Multimedia type data about related history, the architecture, or other related cultural context of historic or artistic relevance might be explored by a mobile user who is intending to learn within the urban environment. Learning from ambient cues is in this way achieved by pointing the device towards the urban sight, capturing an image, and consequently getting information about the object on site and within the focus of attention, i.e., the users current field of view.

A mobile device-based imaging spectrometer for environmental monitoring by attaching a lightweight small module to a commercial digital camera.

PubMed

Cai, Fuhong; Lu, Wen; Shi, Wuxiong; He, Sailing

2017-11-15

Spatially-explicit data are essential for remote sensing of ecological phenomena. Lately, recent innovations in mobile device platforms have led to an upsurge in on-site rapid detection. For instance, CMOS chips in smart phones and digital cameras serve as excellent sensors for scientific research. In this paper, a mobile device-based imaging spectrometer module (weighing about 99 g) is developed and equipped on a Single Lens Reflex camera. Utilizing this lightweight module, as well as commonly used photographic equipment, we demonstrate its utility through a series of on-site multispectral imaging, including ocean (or lake) water-color sensing and plant reflectance measurement. Based on the experiments we obtain 3D spectral image cubes, which can be further analyzed for environmental monitoring. Moreover, our system can be applied to many kinds of cameras, e.g., aerial camera and underwater camera. Therefore, any camera can be upgraded to an imaging spectrometer with the help of our miniaturized module. We believe it has the potential to become a versatile tool for on-site investigation into many applications.

Single-snapshot 2D color measurement by plenoptic imaging system

NASA Astrophysics Data System (ADS)

Masuda, Kensuke; Yamanaka, Yuji; Maruyama, Go; Nagai, Sho; Hirai, Hideaki; Meng, Lingfei; Tosic, Ivana

2014-03-01

Plenoptic cameras enable capture of directional light ray information, thus allowing applications such as digital refocusing, depth estimation, or multiband imaging. One of the most common plenoptic camera architectures contains a microlens array at the conventional image plane and a sensor at the back focal plane of the microlens array. We leverage the multiband imaging (MBI) function of this camera and develop a single-snapshot, single-sensor high color fidelity camera. Our camera is based on a plenoptic system with XYZ filters inserted in the pupil plane of the main lens. To achieve high color measurement precision of this system, we perform an end-to-end optimization of the system model that includes light source information, object information, optical system information, plenoptic image processing and color estimation processing. Optimized system characteristics are exploited to build an XYZ plenoptic colorimetric camera prototype that achieves high color measurement precision. We describe an application of our colorimetric camera to color shading evaluation of display and show that it achieves color accuracy of ΔE<0.01.

The robot's eyes - Stereo vision system for automated scene analysis

NASA Technical Reports Server (NTRS)

Williams, D. S.

1977-01-01

Attention is given to the robot stereo vision system which maintains the image produced by solid-state detector television cameras in a dynamic random access memory called RAPID. The imaging hardware consists of sensors (two solid-state image arrays using a charge injection technique), a video-rate analog-to-digital converter, the RAPID memory, and various types of computer-controlled displays, and preprocessing equipment (for reflexive actions, processing aids, and object detection). The software is aimed at locating objects and transversibility. An object-tracking algorithm is discussed and it is noted that tracking speed is in the 50-75 pixels/s range.

Camera-Model Identification Using Markovian Transition Probability Matrix

NASA Astrophysics Data System (ADS)

Xu, Guanshuo; Gao, Shang; Shi, Yun Qing; Hu, Ruimin; Su, Wei

Detecting the (brands and) models of digital cameras from given digital images has become a popular research topic in the field of digital forensics. As most of images are JPEG compressed before they are output from cameras, we propose to use an effective image statistical model to characterize the difference JPEG 2-D arrays of Y and Cb components from the JPEG images taken by various camera models. Specifically, the transition probability matrices derived from four different directional Markov processes applied to the image difference JPEG 2-D arrays are used to identify statistical difference caused by image formation pipelines inside different camera models. All elements of the transition probability matrices, after a thresholding technique, are directly used as features for classification purpose. Multi-class support vector machines (SVM) are used as the classification tool. The effectiveness of our proposed statistical model is demonstrated by large-scale experimental results.

Automatic Calibration of an Airborne Imaging System to an Inertial Navigation Unit

NASA Technical Reports Server (NTRS)

Ansar, Adnan I.; Clouse, Daniel S.; McHenry, Michael C.; Zarzhitsky, Dimitri V.; Pagdett, Curtis W.

2013-01-01

This software automatically calibrates a camera or an imaging array to an inertial navigation system (INS) that is rigidly mounted to the array or imager. In effect, it recovers the coordinate frame transformation between the reference frame of the imager and the reference frame of the INS. This innovation can automatically derive the camera-to-INS alignment using image data only. The assumption is that the camera fixates on an area while the aircraft flies on orbit. The system then, fully automatically, solves for the camera orientation in the INS frame. No manual intervention or ground tie point data is required.

(99m)Tc-MDP bone scintigraphy of the hand: comparing the use of novel cadmium zinc telluride (CZT) and routine NaI(Tl) detectors.

PubMed

Koulikov, Victoria; Lerman, Hedva; Kesler, Mikhail; Even-Sapir, Einat

2015-12-01

Cadmium zinc telluride (CZT) solid-state detectors have been recently introduced in the field of nuclear medicine in cardiology and breast imaging. The aim of the current study was to evaluate the performance of the novel detectors (CZT) compared to that of the routine NaI(Tl) in bone scintigraphy. A dual-headed CZT-based camera dedicated originally to breast imaging has been used, and in view of the limited size of the detectors, the hands were chosen as the organ for assessment. This is a clinical study. Fifty-eight consecutive patients (total 116 hands) referred for bone scan for suspected hand pathology gave their informed consent to have two acquisitions, using the routine camera and the CZT-based camera. The latter was divided into full-dose full-acquisition time (FD CZT) and reduced-dose short-acquisition time (RD CZT) on CZT technology, so three image sets were available for analysis. Data analysis included comparing the detection of hot lesions and identification of the metacarpophalangeal, proximal interphalangeal, and distal interphalangeal joints. A total of 69 hot lesions were detected on the CZT image sets; of these, 61 were identified as focal sites of uptake on NaI(Tl) data. On FD CZT data, 385 joints were identified compared to 168 on NaI(Tl) data (p < 0.001). There was no statistically significant difference in delineation of joints between FD and RD CZT data as the latter identified 383 joints. Bone scintigraphy using a CZT-based gamma camera is associated with improved lesion detection and anatomic definition. The superior physical characteristics of this technique raised a potential reduction in administered dose and/or acquisition time without compromising image quality.

Polarized fluorescence for skin cancer diagnostic with a multi-aperture camera

NASA Astrophysics Data System (ADS)

Kandimalla, Haripriya; Ramella-Roman, Jessica C.

2008-02-01

Polarized fluorescence has shown some promising results in assessment of skin cancer margins. Researchers have used tetracycline and cross polarization imaging for nonmelanoma skin cancer demarcation as well as investigating endogenous skin polarized fluorescence. In this paper we present a new instrument for polarized fluorescence imaging, able to calculate the full fluorescence Stokes vector in one snapshot. The core of our system is a multi-aperture camera constructed with a two by two lenslet array. Three of the lenses have polarizing elements in front of them, oriented at 0°, + 45°and 90° with respect to light source polarization. A flash lamp combined with a polarizer parallel to the source-camera-sample plane and a UV filter is used as an excitation source. A blue filter in front of the camera system is used to collect only the fluorescent emission of interest and filter out the incident light. In-vitro tests of endogenous and exogenous polarized fluorescence on collagen rich material like bovine tendon were performed and Stokes vector of polarized fluorescence calculated. The system has the advantage of eliminating moving artifacts with the collection of different polarization states and stoke vector in a single snap shot.

Data analysis for GOPEX image frames

NASA Technical Reports Server (NTRS)

Levine, B. M.; Shaik, K. S.; Yan, T.-Y.

1993-01-01

The data analysis based on the image frames received at the Solid State Imaging (SSI) camera of the Galileo Optical Experiment (GOPEX) demonstration conducted between 9-16 Dec. 1992 is described. Laser uplink was successfully established between the ground and the Galileo spacecraft during its second Earth-gravity-assist phase in December 1992. SSI camera frames were acquired which contained images of detected laser pulses transmitted from the Table Mountain Facility (TMF), Wrightwood, California, and the Starfire Optical Range (SOR), Albuquerque, New Mexico. Laser pulse data were processed using standard image-processing techniques at the Multimission Image Processing Laboratory (MIPL) for preliminary pulse identification and to produce public release images. Subsequent image analysis corrected for background noise to measure received pulse intensities. Data were plotted to obtain histograms on a daily basis and were then compared with theoretical results derived from applicable weak-turbulence and strong-turbulence considerations. Processing steps are described and the theories are compared with the experimental results. Quantitative agreement was found in both turbulence regimes, and better agreement would have been found, given more received laser pulses. Future experiments should consider methods to reliably measure low-intensity pulses, and through experimental planning to geometrically locate pulse positions with greater certainty.

Relating transverse ray error and light fields in plenoptic camera images

NASA Astrophysics Data System (ADS)

Schwiegerling, Jim; Tyo, J. Scott

2013-09-01

Plenoptic cameras have emerged in recent years as a technology for capturing light field data in a single snapshot. A conventional digital camera can be modified with the addition of a lenslet array to create a plenoptic camera. The camera image is focused onto the lenslet array. The lenslet array is placed over the camera sensor such that each lenslet forms an image of the exit pupil onto the sensor. The resultant image is an array of circular exit pupil images, each corresponding to the overlying lenslet. The position of the lenslet encodes the spatial information of the scene, whereas as the sensor pixels encode the angular information for light incident on the lenslet. The 4D light field is therefore described by the 2D spatial information and 2D angular information captured by the plenoptic camera. In aberration theory, the transverse ray error relates the pupil coordinates of a given ray to its deviation from the ideal image point in the image plane and is consequently a 4D function as well. We demonstrate a technique for modifying the traditional transverse ray error equations to recover the 4D light field of a general scene. In the case of a well corrected optical system, this light field is easily related to the depth of various objects in the scene. Finally, the effects of sampling with both the lenslet array and the camera sensor on the 4D light field data are analyzed to illustrate the limitations of such systems.

The Earth and Moon As Seen by 2001 Mars Odyssey's Thermal Emission Imaging System

NASA Technical Reports Server (NTRS)

2001-01-01

2001 Mars Odyssey's Thermal Emission Imaging System (THEMIS) took this portrait of the Earth and its companion Moon, using the infrared camera, one of two cameras in the instrument. It was taken at a distance of 3,563,735 kilometers (more than 2 million miles) on April 19, 2001 as the 2001 Mars Odyssey spacecraft left the Earth. From this distance and perspective the camera was able to acquire an image that directly shows the true distance from the Earth to the Moon. The Earth's diameter is about 12,750 km, and the distance from the Earth to the Moon is about 385,000 km, corresponding to 30 Earth diameters. The dark region seen on Earth in the infrared temperature image is the cold south pole, with a temperature of minus 50 degrees Celsius (minus 58 degrees Fahrenheit). The small bright region above it is warm Australia. This image was acquired using the 9.1 um infrared filter, one of nine filters that the instrument will use to map the mineral composition and temperature of the martian surface. From this great distance, each picture element (pixel) in the image corresponds to a region 900 by 900 kilometers or greater in size or about size of the state of Texas. Once Odyssey reaches Mars orbit each infrared pixel will cover a region only 100 by 100 meters on the surface, about the size of a major league baseball field.

CCD-camera-based diffuse optical tomography to study ischemic stroke in preclinical rat models

NASA Astrophysics Data System (ADS)

Lin, Zi-Jing; Niu, Haijing; Liu, Yueming; Su, Jianzhong; Liu, Hanli

2011-02-01

Stroke, due to ischemia or hemorrhage, is the neurological deficit of cerebrovasculature and is the third leading cause of death in the United States. More than 80 percent of stroke patients are ischemic stroke due to blockage of artery in the brain by thrombosis or arterial embolism. Hence, development of an imaging technique to image or monitor the cerebral ischemia and effect of anti-stoke therapy is more than necessary. Near infrared (NIR) optical tomographic technique has a great potential to be utilized as a non-invasive image tool (due to its low cost and portability) to image the embedded abnormal tissue, such as a dysfunctional area caused by ischemia. Moreover, NIR tomographic techniques have been successively demonstrated in the studies of cerebro-vascular hemodynamics and brain injury. As compared to a fiberbased diffuse optical tomographic system, a CCD-camera-based system is more suitable for pre-clinical animal studies due to its simpler setup and lower cost. In this study, we have utilized the CCD-camera-based technique to image the embedded inclusions based on tissue-phantom experimental data. Then, we are able to obtain good reconstructed images by two recently developed algorithms: (1) depth compensation algorithm (DCA) and (2) globally convergent method (GCM). In this study, we will demonstrate the volumetric tomographic reconstructed results taken from tissuephantom; the latter has a great potential to determine and monitor the effect of anti-stroke therapies.

Technical guidance for the development of a solid state image sensor for human low vision image warping

NASA Technical Reports Server (NTRS)

Vanderspiegel, Jan

1994-01-01

This report surveys different technologies and approaches to realize sensors for image warping. The goal is to study the feasibility, technical aspects, and limitations of making an electronic camera with special geometries which implements certain transformations for image warping. This work was inspired by the research done by Dr. Juday at NASA Johnson Space Center on image warping. The study has looked into different solid-state technologies to fabricate image sensors. It is found that among the available technologies, CMOS is preferred over CCD technology. CMOS provides more flexibility to design different functions into the sensor, is more widely available, and is a lower cost solution. By using an architecture with row and column decoders one has the added flexibility of addressing the pixels at random, or read out only part of the image.

A Study of Deep CNN-Based Classification of Open and Closed Eyes Using a Visible Light Camera Sensor.

PubMed

Kim, Ki Wan; Hong, Hyung Gil; Nam, Gi Pyo; Park, Kang Ryoung

2017-06-30

The necessity for the classification of open and closed eyes is increasing in various fields, including analysis of eye fatigue in 3D TVs, analysis of the psychological states of test subjects, and eye status tracking-based driver drowsiness detection. Previous studies have used various methods to distinguish between open and closed eyes, such as classifiers based on the features obtained from image binarization, edge operators, or texture analysis. However, when it comes to eye images with different lighting conditions and resolutions, it can be difficult to find an optimal threshold for image binarization or optimal filters for edge and texture extraction. In order to address this issue, we propose a method to classify open and closed eye images with different conditions, acquired by a visible light camera, using a deep residual convolutional neural network. After conducting performance analysis on both self-collected and open databases, we have determined that the classification accuracy of the proposed method is superior to that of existing methods.

Real-time image processing of TOF range images using a reconfigurable processor system

NASA Astrophysics Data System (ADS)

Hussmann, S.; Knoll, F.; Edeler, T.

2011-07-01

During the last years, Time-of-Flight sensors achieved a significant impact onto research fields in machine vision. In comparison to stereo vision system and laser range scanners they combine the advantages of active sensors providing accurate distance measurements and camera-based systems recording a 2D matrix at a high frame rate. Moreover low cost 3D imaging has the potential to open a wide field of additional applications and solutions in markets like consumer electronics, multimedia, digital photography, robotics and medical technologies. This paper focuses on the currently implemented 4-phase-shift algorithm in this type of sensors. The most time critical operation of the phase-shift algorithm is the arctangent function. In this paper a novel hardware implementation of the arctangent function using a reconfigurable processor system is presented and benchmarked against the state-of-the-art CORDIC arctangent algorithm. Experimental results show that the proposed algorithm is well suited for real-time processing of the range images of TOF cameras.

Lunar Satellite Snaps Image of Earth

NASA Image and Video Library

2014-05-07

This image, captured Feb. 1, 2014, shows a colorized view of Earth from the moon-based perspective of NASA's Lunar Reconnaissance Orbiter. Credit: NASA/Goddard/Arizona State University -- NASA's Lunar Reconnaissance Orbiter (LRO) experiences 12 "earthrises" every day, however LROC (short for LRO Camera) is almost always busy imaging the lunar surface so only rarely does an opportunity arise such that LROC can capture a view of Earth. On Feb. 1, 2014, LRO pitched forward while approaching the moon's north pole allowing the LROC Wide Angle Camera to capture Earth rising above Rozhdestvenskiy crater (112 miles, or 180 km, in diameter). Read more: go.nasa.gov/1oqMlgu NASA image use policy. NASA Goddard Space Flight Center enables NASA’s mission through four scientific endeavors: Earth Science, Heliophysics, Solar System Exploration, and Astrophysics. Goddard plays a leading role in NASA’s accomplishments by contributing compelling scientific knowledge to advance the Agency’s mission. Follow us on Twitter Like us on Facebook Find us on Instagram

DOE Office of Scientific and Technical Information (OSTI.GOV)

Turkington, T.

This education session will cover the physics and operation principles of gamma cameras and PET scanners. The first talk will focus on PET imaging. An overview of the principles of PET imaging will be provided, including positron decay physics, and the transition from 2D to 3D imaging. More recent advances in hardware and software will be discussed, such as time-of-flight imaging, and improvements in reconstruction algorithms that provide for options such as depth-of-interaction corrections. Quantitative applications of PET will be discussed, as well as the requirements for doing accurate quantitation. Relevant performance tests will also be described. Learning Objectives: Bemore » able to describe basic physics principles of PET and operation of PET scanners. Learn about recent advances in PET scanner hardware technology. Be able to describe advances in reconstruction techniques and improvements Be able to list relevant performance tests. The second talk will focus on gamma cameras. The Nuclear Medicine subcommittee has charged a task group (TG177) to develop a report on the current state of physics testing of gamma cameras, SPECT, and SPECT/CT systems. The report makes recommendations for performance tests to be done for routine quality assurance, annual physics testing, and acceptance tests, and identifies those needed satisfy the ACR accreditation program and The Joint Commission imaging standards. The report is also intended to be used as a manual with detailed instructions on how to perform tests under widely varying conditions. Learning Objectives: At the end of the presentation members of the audience will: Be familiar with the tests recommended for routine quality assurance, annual physics testing, and acceptance tests of gamma cameras for planar imaging. Be familiar with the tests recommended for routine quality assurance, annual physics testing, and acceptance tests of SPECT systems. Be familiar with the tests of a SPECT/CT system that include the CT images for SPECT reconstructions. Become knowledgeable of items to be included in annual acceptance testing reports including CT dosimetry and PACS monitor measurements. T. Turkington, GE Healthcare.« less

Microtomography with photon counting detectors: improving the quality of tomographic reconstruction by voxel-space oversampling

NASA Astrophysics Data System (ADS)

Dudak, J.; Zemlicka, J.; Karch, J.; Hermanova, Z.; Kvacek, J.; Krejci, F.

2017-01-01

Photon counting detectors Timepix are known for their unique properties enabling X-ray imaging with extremely high contrast-to-noise ratio. Their applicability has been recently further improved since a dedicated technique for assembling large area Timepix detector arrays was introduced. Despite the fact that the sensitive area of Timepix detectors has been significantly increased, the pixel pitch is kept unchanged (55 microns). This value is much larger compared to widely used and popular X-ray imaging cameras utilizing scintillation crystals and CCD-based read-out. On the other hand, photon counting detectors provide steeper point-spread function. Therefore, with given effective pixel size of an acquired radiography, Timepix detectors provide higher spatial resolution than X-ray cameras with scintillation-based devices unless the image is affected by penumbral blur. In this paper we take an advance of steep PSF of photon counting detectors and test the possibility to improve the quality of computed tomography reconstruction using finer sampling of reconstructed voxel space. The achieved results are presented in comparison with data acquired under the same conditions using a commercially available state-of-the-art CCD X-ray camera.

Comparison of the effectiveness of three retinal camera technologies for malarial retinopathy detection in Malawi

NASA Astrophysics Data System (ADS)

Soliz, Peter; Nemeth, Sheila C.; Barriga, E. Simon; Harding, Simon P.; Lewallen, Susan; Taylor, Terrie E.; MacCormick, Ian J.; Joshi, Vinayak S.

2016-03-01

The purpose of this study was to test the suitability of three available camera technologies (desktop, portable, and iphone based) for imaging comatose children who presented with clinical symptoms of malaria. Ultimately, the results of the project would form the basis for a design of a future camera to screen for malaria retinopathy (MR) in a resource challenged environment. The desktop, portable, and i-phone based cameras were represented by the Topcon, Pictor Plus, and Peek cameras, respectively. These cameras were tested on N=23 children presenting with symptoms of cerebral malaria (CM) at a malaria clinic, Queen Elizabeth Teaching Hospital in Malawi, Africa. Each patient was dilated for binocular indirect ophthalmoscopy (BIO) exam by an ophthalmologist followed by imaging with all three cameras. Each of the cases was graded according to an internationally established protocol and compared to the BIO as the clinical ground truth. The reader used three principal retinal lesions as markers for MR: hemorrhages, retinal whitening, and vessel discoloration. The study found that the mid-priced Pictor Plus hand-held camera performed considerably better than the lower price mobile phone-based camera, and slightly the higher priced table top camera. When comparing the readings of digital images against the clinical reference standard (BIO), the Pictor Plus camera had sensitivity and specificity for MR of 100% and 87%, respectively. This compares to a sensitivity and specificity of 87% and 75% for the i-phone based camera and 100% and 75% for the desktop camera. The drawback of all the cameras were their limited field of view which did not allow complete view of the periphery where vessel discoloration occurs most frequently. The consequence was that vessel discoloration was not addressed in this study. None of the cameras offered real-time image quality assessment to ensure high quality images to afford the best possible opportunity for reading by a remotely located specialist.

Advanced imaging system

NASA Technical Reports Server (NTRS)

1992-01-01

This document describes the Advanced Imaging System CCD based camera. The AIS1 camera system was developed at Photometric Ltd. in Tucson, Arizona as part of a Phase 2 SBIR contract No. NAS5-30171 from the NASA/Goddard Space Flight Center in Greenbelt, Maryland. The camera project was undertaken as a part of the Space Telescope Imaging Spectrograph (STIS) project. This document is intended to serve as a complete manual for the use and maintenance of the camera system. All the different parts of the camera hardware and software are discussed and complete schematics and source code listings are provided.

Research on the electro-optical assistant landing system based on the dual camera photogrammetry algorithm

NASA Astrophysics Data System (ADS)

Mi, Yuhe; Huang, Yifan; Li, Lin

2015-08-01

Based on the location technique of beacon photogrammetry, Dual Camera Photogrammetry (DCP) algorithm was used to assist helicopters landing on the ship. In this paper, ZEMAX was used to simulate the two Charge Coupled Device (CCD) cameras imaging four beacons on both sides of the helicopter and output the image to MATLAB. Target coordinate systems, image pixel coordinate systems, world coordinate systems and camera coordinate systems were established respectively. According to the ideal pin-hole imaging model, the rotation matrix and translation vector of the target coordinate systems and the camera coordinate systems could be obtained by using MATLAB to process the image information and calculate the linear equations. On the basis mentioned above, ambient temperature and the positions of the beacons and cameras were changed in ZEMAX to test the accuracy of the DCP algorithm in complex sea status. The numerical simulation shows that in complex sea status, the position measurement accuracy can meet the requirements of the project.

Ranging Apparatus and Method Implementing Stereo Vision System

NASA Technical Reports Server (NTRS)

Li, Larry C. (Inventor); Cox, Brian J. (Inventor)

1997-01-01

A laser-directed ranging system for use in telerobotics applications and other applications involving physically handicapped individuals. The ranging system includes a left and right video camera mounted on a camera platform, and a remotely positioned operator. The position of the camera platform is controlled by three servo motors to orient the roll axis, pitch axis and yaw axis of the video cameras, based upon an operator input such as head motion. A laser is provided between the left and right video camera and is directed by the user to point to a target device. The images produced by the left and right video cameras are processed to eliminate all background images except for the spot created by the laser. This processing is performed by creating a digital image of the target prior to illumination by the laser, and then eliminating common pixels from the subsequent digital image which includes the laser spot. The horizontal disparity between the two processed images is calculated for use in a stereometric ranging analysis from which range is determined.

A 3D photographic capsule endoscope system with full field of view

NASA Astrophysics Data System (ADS)

Ou-Yang, Mang; Jeng, Wei-De; Lai, Chien-Cheng; Kung, Yi-Chinn; Tao, Kuan-Heng

2013-09-01

Current capsule endoscope uses one camera to capture the surface image in the intestine. It can only observe the abnormal point, but cannot know the exact information of this abnormal point. Using two cameras can generate 3D images, but the visual plane changes while capsule endoscope rotates. It causes that two cameras can't capture the images information completely. To solve this question, this research provides a new kind of capsule endoscope to capture 3D images, which is 'A 3D photographic capsule endoscope system'. The system uses three cameras to capture images in real time. The advantage is increasing the viewing range up to 2.99 times respect to the two camera system. The system can accompany 3D monitor provides the exact information of symptom points, helping doctors diagnose the disease.

A detailed comparison of single-camera light-field PIV and tomographic PIV

NASA Astrophysics Data System (ADS)

Shi, Shengxian; Ding, Junfei; Atkinson, Callum; Soria, Julio; New, T. H.

2018-03-01

This paper conducts a comprehensive study between the single-camera light-field particle image velocimetry (LF-PIV) and the multi-camera tomographic particle image velocimetry (Tomo-PIV). Simulation studies were first performed using synthetic light-field and tomographic particle images, which extensively examine the difference between these two techniques by varying key parameters such as pixel to microlens ratio (PMR), light-field camera Tomo-camera pixel ratio (LTPR), particle seeding density and tomographic camera number. Simulation results indicate that the single LF-PIV can achieve accuracy consistent with that of multi-camera Tomo-PIV, but requires the use of overall greater number of pixels. Experimental studies were then conducted by simultaneously measuring low-speed jet flow with single-camera LF-PIV and four-camera Tomo-PIV systems. Experiments confirm that given a sufficiently high pixel resolution, a single-camera LF-PIV system can indeed deliver volumetric velocity field measurements for an equivalent field of view with a spatial resolution commensurate with those of multi-camera Tomo-PIV system, enabling accurate 3D measurements in applications where optical access is limited.

High dynamic range image acquisition based on multiplex cameras

NASA Astrophysics Data System (ADS)

Zeng, Hairui; Sun, Huayan; Zhang, Tinghua

2018-03-01

High dynamic image is an important technology of photoelectric information acquisition, providing higher dynamic range and more image details, and it can better reflect the real environment, light and color information. Currently, the method of high dynamic range image synthesis based on different exposure image sequences cannot adapt to the dynamic scene. It fails to overcome the effects of moving targets, resulting in the phenomenon of ghost. Therefore, a new high dynamic range image acquisition method based on multiplex cameras system was proposed. Firstly, different exposure images sequences were captured with the camera array, using the method of derivative optical flow based on color gradient to get the deviation between images, and aligned the images. Then, the high dynamic range image fusion weighting function was established by combination of inverse camera response function and deviation between images, and was applied to generated a high dynamic range image. The experiments show that the proposed method can effectively obtain high dynamic images in dynamic scene, and achieves good results.

On the feasibility of tomographic-PIV with low pulse energy illumination in a lifted turbulent jet flame

NASA Astrophysics Data System (ADS)

Boxx, I.; Carter, C. D.; Meier, W.

2014-08-01

Tomographic particle image velocimetry (tomographic-PIV) is a recently developed measurement technique used to acquire volumetric velocity field data in liquid and gaseous flows. The technique relies on line-of-sight reconstruction of the rays between a 3D particle distribution and a multi-camera imaging system. In a turbulent flame, however, index-of-refraction variations resulting from local heat-release may inhibit reconstruction and thereby render the technique infeasible. The objective of this study was to test the efficacy of tomographic-PIV in a turbulent flame. An additional goal was to determine the feasibility of acquiring usable tomographic-PIV measurements in a turbulent flame at multi-kHz acquisition rates with current-generation laser and camera technology. To this end, a setup consisting of four complementary metal oxide semiconductor cameras and a dual-cavity Nd:YAG laser was implemented to test the technique in a lifted turbulent jet flame. While the cameras were capable of kHz-rate image acquisition, the laser operated at a pulse repetition rate of only 10 Hz. However, use of this laser allowed exploration of the required pulse energy and thus power for a kHz-rate system. The imaged region was 29 × 28 × 2.7 mm in size. The tomographic reconstruction of the 3D particle distributions was accomplished using the multiplicative algebraic reconstruction technique. The results indicate that volumetric velocimetry via tomographic-PIV is feasible with pulse energies of 25 mJ, which is within the capability of current-generation kHz-rate diode-pumped solid-state lasers.

Convolutional Neural Network-Based Shadow Detection in Images Using Visible Light Camera Sensor.

PubMed

Kim, Dong Seop; Arsalan, Muhammad; Park, Kang Ryoung

2018-03-23

Recent developments in intelligence surveillance camera systems have enabled more research on the detection, tracking, and recognition of humans. Such systems typically use visible light cameras and images, in which shadows make it difficult to detect and recognize the exact human area. Near-infrared (NIR) light cameras and thermal cameras are used to mitigate this problem. However, such instruments require a separate NIR illuminator, or are prohibitively expensive. Existing research on shadow detection in images captured by visible light cameras have utilized object and shadow color features for detection. Unfortunately, various environmental factors such as illumination change and brightness of background cause detection to be a difficult task. To overcome this problem, we propose a convolutional neural network-based shadow detection method. Experimental results with a database built from various outdoor surveillance camera environments, and from the context-aware vision using image-based active recognition (CAVIAR) open database, show that our method outperforms previous works.

Convolutional Neural Network-Based Shadow Detection in Images Using Visible Light Camera Sensor

PubMed Central

Kim, Dong Seop; Arsalan, Muhammad; Park, Kang Ryoung

2018-01-01

Recent developments in intelligence surveillance camera systems have enabled more research on the detection, tracking, and recognition of humans. Such systems typically use visible light cameras and images, in which shadows make it difficult to detect and recognize the exact human area. Near-infrared (NIR) light cameras and thermal cameras are used to mitigate this problem. However, such instruments require a separate NIR illuminator, or are prohibitively expensive. Existing research on shadow detection in images captured by visible light cameras have utilized object and shadow color features for detection. Unfortunately, various environmental factors such as illumination change and brightness of background cause detection to be a difficult task. To overcome this problem, we propose a convolutional neural network-based shadow detection method. Experimental results with a database built from various outdoor surveillance camera environments, and from the context-aware vision using image-based active recognition (CAVIAR) open database, show that our method outperforms previous works. PMID:29570690

SU-D-BRC-07: System Design for a 3D Volumetric Scintillation Detector Using SCMOS Cameras

DOE Office of Scientific and Technical Information (OSTI.GOV)

Darne, C; Robertson, D; Alsanea, F

2016-06-15

Purpose: The purpose of this project is to build a volumetric scintillation detector for quantitative imaging of 3D dose distributions of proton beams accurately in near real-time. Methods: The liquid scintillator (LS) detector consists of a transparent acrylic tank (20×20×20 cm{sup 3}) filled with a liquid scintillator that when irradiated with protons generates scintillation light. To track rapid spatial and dose variations in spot scanning proton beams we used three scientific-complementary metal-oxide semiconductor (sCMOS) imagers (2560×2160 pixels). The cameras collect optical signal from three orthogonal projections. To reduce system footprint two mirrors oriented at 45° to the tank surfaces redirectmore » scintillation light to cameras for capturing top and right views. Selection of fixed focal length objective lenses for these cameras was based on their ability to provide large depth of field (DoF) and required field of view (FoV). Multiple cross-hairs imprinted on the tank surfaces allow for image corrections arising from camera perspective and refraction. Results: We determined that by setting sCMOS to 16-bit dynamic range, truncating its FoV (1100×1100 pixels) to image the entire volume of the LS detector, and using 5.6 msec integration time imaging rate can be ramped up to 88 frames per second (fps). 20 mm focal length lens provides a 20 cm imaging DoF and 0.24 mm/pixel resolution. Master-slave camera configuration enable the slaves to initiate image acquisition instantly (within 2 µsec) after receiving a trigger signal. A computer with 128 GB RAM was used for spooling images from the cameras and can sustain a maximum recording time of 2 min per camera at 75 fps. Conclusion: The three sCMOS cameras are capable of high speed imaging. They can therefore be used for quick, high-resolution, and precise mapping of dose distributions from scanned spot proton beams in three dimensions.« less

Remote camera observations of lava dome growth at Mount St. Helens, Washington, October 2004 to February 2006: Chapter 11 in A volcano rekindled: the renewed eruption of Mount St. Helens, 2004-2006

USGS Publications Warehouse

Poland, Michael P.; Dzurisin, Daniel; LaHusen, Richard G.; Major, John J.; Lapcewich, Dennis; Endo, Elliot T.; Gooding, Daniel J.; Schilling, Steve P.; Janda, Christine G.; Sherrod, David R.; Scott, William E.; Stauffer, Peter H.

2008-01-01

Images from a Web-based camera (Webcam) located 8 km north of Mount St. Helens and a network of remote, telemetered digital cameras were used to observe eruptive activity at the volcano between October 2004 and February 2006. The cameras offered the advantages of low cost, low power, flexibility in deployment, and high spatial and temporal resolution. Images obtained from the cameras provided important insights into several aspects of dome extrusion, including rockfalls, lava extrusion rates, and explosive activity. Images from the remote, telemetered digital cameras were assembled into time-lapse animations of dome extrusion that supported monitoring, research, and outreach efforts. The wide-ranging utility of remote camera imagery should motivate additional work, especially to develop the three-dimensional quantitative capabilities of terrestrial camera networks.

Overview of Digital Forensics Algorithms in Dslr Cameras

NASA Astrophysics Data System (ADS)

Aminova, E.; Trapeznikov, I.; Priorov, A.

2017-05-01

The widespread usage of the mobile technologies and the improvement of the digital photo devices getting has led to more frequent cases of falsification of images including in the judicial practice. Consequently, the actual task for up-to-date digital image processing tools is the development of algorithms for determining the source and model of the DSLR (Digital Single Lens Reflex) camera and improve image formation algorithms. Most research in this area based on the mention that the extraction of unique sensor trace of DSLR camera could be possible on the certain stage of the imaging process into the camera. It is considered that the study focuses on the problem of determination of unique feature of DSLR cameras based on optical subsystem artifacts and sensor noises.

Pulsed-neutron imaging by a high-speed camera and center-of-gravity processing

NASA Astrophysics Data System (ADS)

Mochiki, K.; Uragaki, T.; Koide, J.; Kushima, Y.; Kawarabayashi, J.; Taketani, A.; Otake, Y.; Matsumoto, Y.; Su, Y.; Hiroi, K.; Shinohara, T.; Kai, T.

2018-01-01

Pulsed-neutron imaging is attractive technique in the research fields of energy-resolved neutron radiography and RANS (RIKEN) and RADEN (J-PARC/JAEA) are small and large accelerator-driven pulsed-neutron facilities for its imaging, respectively. To overcome the insuficient spatial resolution of the conunting type imaging detectors like μ NID, nGEM and pixelated detectors, camera detectors combined with a neutron color image intensifier were investigated. At RANS center-of-gravity technique was applied to spots image obtained by a CCD camera and the technique was confirmed to be effective for improving spatial resolution. At RADEN a high-frame-rate CMOS camera was used and super resolution technique was applied and it was recognized that the spatial resolution was futhermore improved.

Automatic Calibration of Stereo-Cameras Using Ordinary Chess-Board Patterns

NASA Astrophysics Data System (ADS)

Prokos, A.; Kalisperakis, I.; Petsa, E.; Karras, G.

2012-07-01

Automation of camera calibration is facilitated by recording coded 2D patterns. Our toolbox for automatic camera calibration using images of simple chess-board patterns is freely available on the Internet. But it is unsuitable for stereo-cameras whose calibration implies recovering camera geometry and their true-to-scale relative orientation. In contrast to all reported methods requiring additional specific coding to establish an object space coordinate system, a toolbox for automatic stereo-camera calibration relying on ordinary chess-board patterns is presented here. First, the camera calibration algorithm is applied to all image pairs of the pattern to extract nodes of known spacing, order them in rows and columns, and estimate two independent camera parameter sets. The actual node correspondences on stereo-pairs remain unknown. Image pairs of a textured 3D scene are exploited for finding the fundamental matrix of the stereo-camera by applying RANSAC to point matches established with the SIFT algorithm. A node is then selected near the centre of the left image; its match on the right image is assumed as the node closest to the corresponding epipolar line. This yields matches for all nodes (since these have already been ordered), which should also satisfy the 2D epipolar geometry. Measures for avoiding mismatching are taken. With automatically estimated initial orientation values, a bundle adjustment is performed constraining all pairs on a common (scaled) relative orientation. Ambiguities regarding the actual exterior orientations of the stereo-camera with respect to the pattern are irrelevant. Results from this automatic method show typical precisions not above 1/4 pixels for 640×480 web cameras.

Evaluation of Acquisition Strategies for Image-Based Construction Site Monitoring

NASA Astrophysics Data System (ADS)

Tuttas, S.; Braun, A.; Borrmann, A.; Stilla, U.

2016-06-01

Construction site monitoring is an essential task for keeping track of the ongoing construction work and providing up-to-date information for a Building Information Model (BIM). The BIM contains the as-planned states (geometry, schedule, costs, ...) of a construction project. For updating, the as-built state has to be acquired repeatedly and compared to the as-planned state. In the approach presented here, a 3D representation of the as-built state is calculated from photogrammetric images using multi-view stereo reconstruction. On construction sites one has to cope with several difficulties like security aspects, limited accessibility, occlusions or construction activity. Different acquisition strategies and techniques, namely (i) terrestrial acquisition with a hand-held camera, (ii) aerial acquisition using a Unmanned Aerial Vehicle (UAV) and (iii) acquisition using a fixed stereo camera pair at the boom of the crane, are tested on three test sites. They are assessed considering the special needs for the monitoring tasks and limitations on construction sites. The three scenarios are evaluated based on the ability of automation, the required effort for acquisition, the necessary equipment and its maintaining, disturbance of the construction works, and on the accuracy and completeness of the resulting point clouds. Based on the experiences during the test cases the following conclusions can be drawn: Terrestrial acquisition has the lowest requirements on the device setup but lacks on automation and coverage. The crane camera shows the lowest flexibility but the highest grade of automation. The UAV approach can provide the best coverage by combining nadir and oblique views, but can be limited by obstacles and security aspects. The accuracy of the point clouds is evaluated based on plane fitting of selected building parts. The RMS errors of the fitted parts range from 1 to a few cm for the UAV and the hand-held scenario. First results show that the crane camera approach has the potential to reach the same accuracy level.

Innovative uses of GigaPan Technology for Onsite and Distance Education

NASA Astrophysics Data System (ADS)

Bentley, C.; Schott, R. C.; Piatek, J. L.; Richards, B.

2013-12-01

GigaPans are gigapixel panoramic images that can be viewed at a wide range of magnifications, allowing users to explore them in various degrees of detail from the smallest scale to the full image extent. In addition to panoramic images captured with the GigaPan camera mount ('Dry Falls' - http://www.gigapan.com/gigapans/89093), users can also upload annotated images (For example, 'Massanutten sandstone slab with trace fossils (annotated)', http://www.gigapan.com/gigapans/124295) and satellite images (For example, 'Geology vs. Topography - State of Connecticut', http://www.gigapan.com/gigapans/111265). Panoramas with similar topics have been gathered together on the site in galleries, both user-generated and site-curated (For example, http://www.gigapan.com/galleries?categories=geology&page=1). Further innovations in display technology have also led to the development of improved viewers (for example, the annotations in the image linked above can be explored via paired viewers at http://coursecontent.nic.edu/bdrichards/gigapixelimages/callanview) GigaPan panoramas can be created through use of the GigaPan robotic camera mount and a digital camera (different models of the camera mount are available and work with a wide range of cameras). The camera mount can be used to create high-resolution pans ranging in scale from hand sample to outcrop up to landscape via the stitching software included with the robotic mount. The software can also be used to generate GigaPan images from other sources, such as thin section or satellite images, so these images can also be viewed with the online viewer. GigaPan images are typically viewed via a web-based interface that allows the user to interact with the image from the limits of the image detail up to the full panorama. After uploading, information can be added to panoramas with both text captions and geo-referencing (geo-located panoramas can then be viewed in Google Earth). Users can record specific locations and zoom levels in these images via "snapshots": these snapshots can direct others to the same location in the image as well as generate conversations with attached text comments. Users can also group related GigaPans by creating "galleries" of thematically related images (similar to photo albums). Gigapixel images can also be formatted for processing and viewing in an increasing number of platforms/modes as software vendors and internet browsers begin to provide 'add-in' support. This opens up opportunities for innovative adaptations for geoscience education. (For example, http://coursecontent.nic.edu/bdrichards/gigapixelimages/dryfalls) Specific applications of these images for geoscience educations include classroom activities and independent exercises that encourage students to take an active inquiry-based approach to understanding geoscience concepts at multiple skill levels. GigaPans in field research serve as both records of field locations and additional datasets for detailed analyses, such as observing color changes or variations in grain size. Related GigaPans can be also be presented together when embedded in webpages, useful for generating exercises for education purposes or for analyses of outcrops from the macro (landscape, outcrop) down to the micro scale (hand sample, thin section).

A Reconfigurable Real-Time Compressive-Sampling Camera for Biological Applications

PubMed Central

Fu, Bo; Pitter, Mark C.; Russell, Noah A.

2011-01-01

Many applications in biology, such as long-term functional imaging of neural and cardiac systems, require continuous high-speed imaging. This is typically not possible, however, using commercially available systems. The frame rate and the recording time of high-speed cameras are limited by the digitization rate and the capacity of on-camera memory. Further restrictions are often imposed by the limited bandwidth of the data link to the host computer. Even if the system bandwidth is not a limiting factor, continuous high-speed acquisition results in very large volumes of data that are difficult to handle, particularly when real-time analysis is required. In response to this issue many cameras allow a predetermined, rectangular region of interest (ROI) to be sampled, however this approach lacks flexibility and is blind to the image region outside of the ROI. We have addressed this problem by building a camera system using a randomly-addressable CMOS sensor. The camera has a low bandwidth, but is able to capture continuous high-speed images of an arbitrarily defined ROI, using most of the available bandwidth, while simultaneously acquiring low-speed, full frame images using the remaining bandwidth. In addition, the camera is able to use the full-frame information to recalculate the positions of targets and update the high-speed ROIs without interrupting acquisition. In this way the camera is capable of imaging moving targets at high-speed while simultaneously imaging the whole frame at a lower speed. We have used this camera system to monitor the heartbeat and blood cell flow of a water flea (Daphnia) at frame rates in excess of 1500 fps. PMID:22028852

Image quality assessment for selfies with and without super resolution

NASA Astrophysics Data System (ADS)

Kubota, Aya; Gohshi, Seiichi

2018-04-01

With the advent of cellphone cameras, in particular, on smartphones, many people now take photos of themselves alone and with others in the frame; such photos are popularly known as "selfies". Most smartphones are equipped with two cameras: the front-facing and rear cameras. The camera located on the back of the smartphone is referred to as the "out-camera," whereas the one located on the front of the smartphone is called the "in-camera." In-cameras are mainly used for selfies. Some smartphones feature high-resolution cameras. However, the original image quality cannot be obtained because smartphone cameras often have low-performance lenses. Super resolution (SR) is one of the recent technological advancements that has increased image resolution. We developed a new SR technology that can be processed on smartphones. Smartphones with new SR technology are currently available in the market have already registered sales. However, the effective use of new SR technology has not yet been verified. Comparing the image quality with and without SR on smartphone display is necessary to confirm the usefulness of this new technology. Methods that are based on objective and subjective assessments are required to quantitatively measure image quality. It is known that the typical object assessment value, such as Peak Signal to Noise Ratio (PSNR), does not go together with how we feel when we assess image/video. When digital broadcast started, the standard was determined using subjective assessment. Although subjective assessment usually comes at high cost because of personnel expenses for observers, the results are highly reproducible when they are conducted under right conditions and statistical analysis. In this study, the subjective assessment results for selfie images are reported.

An efficient multiple exposure image fusion in JPEG domain

NASA Astrophysics Data System (ADS)

Hebbalaguppe, Ramya; Kakarala, Ramakrishna

2012-01-01

In this paper, we describe a method to fuse multiple images taken with varying exposure times in the JPEG domain. The proposed algorithm finds its application in HDR image acquisition and image stabilization for hand-held devices like mobile phones, music players with cameras, digital cameras etc. Image acquisition at low light typically results in blurry and noisy images for hand-held camera's. Altering camera settings like ISO sensitivity, exposure times and aperture for low light image capture results in noise amplification, motion blur and reduction of depth-of-field respectively. The purpose of fusing multiple exposures is to combine the sharp details of the shorter exposure images with high signal-to-noise-ratio (SNR) of the longer exposure images. The algorithm requires only a single pass over all images, making it efficient. It comprises of - sigmoidal boosting of shorter exposed images, image fusion, artifact removal and saturation detection. Algorithm does not need more memory than a single JPEG macro block to be kept in memory making it feasible to be implemented as the part of a digital cameras hardware image processing engine. The Artifact removal step reuses the JPEGs built-in frequency analysis and hence benefits from the considerable optimization and design experience that is available for JPEG.

Thermal Effects on Camera Focal Length in Messenger Star Calibration and Orbital Imaging

NASA Astrophysics Data System (ADS)

Burmeister, S.; Elgner, S.; Preusker, F.; Stark, A.; Oberst, J.

2018-04-01

We analyse images taken by the MErcury Surface, Space ENviorment, GEochemistry, and Ranging (MESSENGER) spacecraft for the camera's thermal response in the harsh thermal environment near Mercury. Specifically, we study thermally induced variations in focal length of the Mercury Dual Imaging System (MDIS). Within the several hundreds of images of star fields, the Wide Angle Camera (WAC) typically captures up to 250 stars in one frame of the panchromatic channel. We measure star positions and relate these to the known star coordinates taken from the Tycho-2 catalogue. We solve for camera pointing, the focal length parameter and two non-symmetrical distortion parameters for each image. Using data from the temperature sensors on the camera focal plane we model a linear focal length function in the form of f(T) = A0 + A1 T. Next, we use images from MESSENGER's orbital mapping mission. We deal with large image blocks, typically used for the production of a high-resolution digital terrain models (DTM). We analyzed images from the combined quadrangles H03 and H07, a selected region, covered by approx. 10,600 images, in which we identified about 83,900 tiepoints. Using bundle block adjustments, we solved for the unknown coordinates of the control points, the pointing of the camera - as well as the camera's focal length. We then fit the above linear function with respect to the focal plane temperature. As a result, we find a complex response of the camera to thermal conditions of the spacecraft. To first order, we see a linear increase by approx. 0.0107 mm per degree temperature for the Narrow-Angle Camera (NAC). This is in agreement with the observed thermal response seen in images of the panchromatic channel of the WAC. Unfortunately, further comparisons of results from the two methods, both of which use different portions of the available image data, are limited. If leaving uncorrected, these effects may pose significant difficulties in the photogrammetric analysis, specifically these may be responsible for erroneous longwavelength trends in topographic models.

CAOS-CMOS camera.

PubMed

Riza, Nabeel A; La Torre, Juan Pablo; Amin, M Junaid

2016-06-13

Proposed and experimentally demonstrated is the CAOS-CMOS camera design that combines the coded access optical sensor (CAOS) imager platform with the CMOS multi-pixel optical sensor. The unique CAOS-CMOS camera engages the classic CMOS sensor light staring mode with the time-frequency-space agile pixel CAOS imager mode within one programmable optical unit to realize a high dynamic range imager for extreme light contrast conditions. The experimentally demonstrated CAOS-CMOS camera is built using a digital micromirror device, a silicon point-photo-detector with a variable gain amplifier, and a silicon CMOS sensor with a maximum rated 51.3 dB dynamic range. White light imaging of three different brightness simultaneously viewed targets, that is not possible by the CMOS sensor, is achieved by the CAOS-CMOS camera demonstrating an 82.06 dB dynamic range. Applications for the camera include industrial machine vision, welding, laser analysis, automotive, night vision, surveillance and multispectral military systems.

Color reproduction software for a digital still camera

NASA Astrophysics Data System (ADS)

Lee, Bong S.; Park, Du-Sik; Nam, Byung D.

1998-04-01

We have developed a color reproduction software for a digital still camera. The image taken by the camera was colorimetrically reproduced on the monitor after characterizing the camera and the monitor, and color matching between two devices. The reproduction was performed at three levels; level processing, gamma correction, and color transformation. The image contrast was increased after the level processing adjusting the level of dark and bright portions of the image. The relationship between the level processed digital values and the measured luminance values of test gray samples was calculated, and the gamma of the camera was obtained. The method for getting the unknown monitor gamma was proposed. As a result, the level processed values were adjusted by the look-up table created by the camera and the monitor gamma correction. For a color transformation matrix for the camera, 3 by 3 or 3 by 4 matrix was used, which was calculated by the regression between the gamma corrected values and the measured tristimulus values of each test color samples the various reproduced images were displayed on the dialogue box implemented in our software, which were generated according to four illuminations for the camera and three color temperatures for the monitor. An user can easily choose he best reproduced image comparing each others.

Blur spot limitations in distal endoscope sensors

NASA Astrophysics Data System (ADS)

Yaron, Avi; Shechterman, Mark; Horesh, Nadav

2006-02-01

In years past, the picture quality of electronic video systems was limited by the image sensor. In the present, the resolution of miniature image sensors, as in medical endoscopy, is typically superior to the resolution of the optical system. This "excess resolution" is utilized by Visionsense to create stereoscopic vision. Visionsense has developed a single chip stereoscopic camera that multiplexes the horizontal dimension of the image sensor into two (left and right) images, compensates the blur phenomena, and provides additional depth resolution without sacrificing planar resolution. The camera is based on a dual-pupil imaging objective and an image sensor coated by an array of microlenses (a plenoptic camera). The camera has the advantage of being compact, providing simultaneous acquisition of left and right images, and offering resolution comparable to a dual chip stereoscopic camera with low to medium resolution imaging lenses. A stereoscopic vision system provides an improved 3-dimensional perspective of intra-operative sites that is crucial for advanced minimally invasive surgery and contributes to surgeon performance. An additional advantage of single chip stereo sensors is improvement of tolerance to electronic signal noise.

Automatic Orientation of Large Blocks of Oblique Images

NASA Astrophysics Data System (ADS)

Rupnik, E.; Nex, F.; Remondino, F.

2013-05-01

Nowadays, multi-camera platforms combining nadir and oblique cameras are experiencing a revival. Due to their advantages such as ease of interpretation, completeness through mitigation of occluding areas, as well as system accessibility, they have found their place in numerous civil applications. However, automatic post-processing of such imagery still remains a topic of research. Configuration of cameras poses a challenge on the traditional photogrammetric pipeline used in commercial software and manual measurements are inevitable. For large image blocks it is certainly an impediment. Within theoretical part of the work we review three common least square adjustment methods and recap on possible ways for a multi-camera system orientation. In the practical part we present an approach that successfully oriented a block of 550 images acquired with an imaging system composed of 5 cameras (Canon Eos 1D Mark III) with different focal lengths. Oblique cameras are rotated in the four looking directions (forward, backward, left and right) by 45° with respect to the nadir camera. The workflow relies only upon open-source software: a developed tool to analyse image connectivity and Apero to orient the image block. The benefits of the connectivity tool are twofold: in terms of computational time and success of Bundle Block Adjustment. It exploits the georeferenced information provided by the Applanix system in constraining feature point extraction to relevant images only, and guides the concatenation of images during the relative orientation. Ultimately an absolute transformation is performed resulting in mean re-projection residuals equal to 0.6 pix.

Error modeling and analysis of star cameras for a class of 1U spacecraft

NASA Astrophysics Data System (ADS)

Fowler, David M.

As spacecraft today become increasingly smaller, the demand for smaller components and sensors rises as well. The smartphone, a cutting edge consumer technology, has impressive collections of both sensors and processing capabilities and may have the potential to fill this demand in the spacecraft market. If the technologies of a smartphone can be used in space, the cost of building miniature satellites would drop significantly and give a boost to the aerospace and scientific communities. Concentrating on the problem of spacecraft orientation, this study sets ground to determine the capabilities of a smartphone camera when acting as a star camera. Orientations determined from star images taken from a smartphone camera are compared to those of higher quality cameras in order to determine the associated accuracies. The results of the study reveal the abilities of low-cost off-the-shelf imagers in space and give a starting point for future research in the field. The study began with a complete geometric calibration of each analyzed imager such that all comparisons start from the same base. After the cameras were calibrated, image processing techniques were introduced to correct for atmospheric, lens, and image sensor effects. Orientations for each test image are calculated through methods of identifying the stars exposed on each image. Analyses of these orientations allow the overall errors of each camera to be defined and provide insight into the abilities of low-cost imagers.

Night Vision Camera

NASA Technical Reports Server (NTRS)

1996-01-01

PixelVision, Inc. developed the Night Video NV652 Back-illuminated CCD Camera, based on the expertise of a former Jet Propulsion Laboratory employee and a former employee of Scientific Imaging Technologies, Inc. The camera operates without an image intensifier, using back-illuminated and thinned CCD technology to achieve extremely low light level imaging performance. The advantages of PixelVision's system over conventional cameras include greater resolution and better target identification under low light conditions, lower cost and a longer lifetime. It is used commercially for research and aviation.

Center for Coastline Security Technology, Year 3

DTIC Science & Technology

2008-05-01

Polarization control for 3D Imaging with the Sony SRX-R105 Digital Cinema Projectors 3.4 HDMAX Camera and Sony SRX-R105 Projector Configuration for 3D...HDMAX Camera Pair Figure 3.2 Sony SRX-R105 Digital Cinema Projector Figure 3.3 Effect of camera rotation on projected overlay image. Figure 3.4...system that combines a pair of FAU’s HD-MAX video cameras with a pair of Sony SRX-R105 digital cinema projectors for stereo imaging and projection

Dual cameras acquisition and display system of retina-like sensor camera and rectangular sensor camera

NASA Astrophysics Data System (ADS)

Cao, Nan; Cao, Fengmei; Lin, Yabin; Bai, Tingzhu; Song, Shengyu

2015-04-01

For a new kind of retina-like senor camera and a traditional rectangular sensor camera, dual cameras acquisition and display system need to be built. We introduce the principle and the development of retina-like senor. Image coordinates transformation and interpolation based on sub-pixel interpolation need to be realized for our retina-like sensor's special pixels distribution. The hardware platform is composed of retina-like senor camera, rectangular sensor camera, image grabber and PC. Combined the MIL and OpenCV library, the software program is composed in VC++ on VS 2010. Experience results show that the system can realizes two cameras' acquisition and display.

The Effect of Camera Angle and Image Size on Source Credibility and Interpersonal Attraction.

ERIC Educational Resources Information Center

McCain, Thomas A.; Wakshlag, Jacob J.

The purpose of this study was to examine the effects of two nonverbal visual variables (camera angle and image size) on variables developed in a nonmediated context (source credibility and interpersonal attraction). Camera angle and image size were manipulated in eight video taped television newscasts which were subsequently presented to eight…

Development of a piecewise linear omnidirectional 3D image registration method

NASA Astrophysics Data System (ADS)

Bae, Hyunsoo; Kang, Wonjin; Lee, SukGyu; Kim, Youngwoo

2016-12-01

This paper proposes a new piecewise linear omnidirectional image registration method. The proposed method segments an image captured by multiple cameras into 2D segments defined by feature points of the image and then stitches each segment geometrically by considering the inclination of the segment in the 3D space. Depending on the intended use of image registration, the proposed method can be used to improve image registration accuracy or reduce the computation time in image registration because the trade-off between the computation time and image registration accuracy can be controlled for. In general, nonlinear image registration methods have been used in 3D omnidirectional image registration processes to reduce image distortion by camera lenses. The proposed method depends on a linear transformation process for omnidirectional image registration, and therefore it can enhance the effectiveness of the geometry recognition process, increase image registration accuracy by increasing the number of cameras or feature points of each image, increase the image registration speed by reducing the number of cameras or feature points of each image, and provide simultaneous information on shapes and colors of captured objects.

SpectraCAM SPM: a camera system with high dynamic range for scientific and medical applications

NASA Astrophysics Data System (ADS)

Bhaskaran, S.; Baiko, D.; Lungu, G.; Pilon, M.; VanGorden, S.

2005-08-01

A scientific camera system having high dynamic range designed and manufactured by Thermo Electron for scientific and medical applications is presented. The newly developed CID820 image sensor with preamplifier-per-pixel technology is employed in this camera system. The 4 Mega-pixel imaging sensor has a raw dynamic range of 82dB. Each high-transparent pixel is based on a preamplifier-per-pixel architecture and contains two photogates for non-destructive readout of the photon-generated charge (NDRO). Readout is achieved via parallel row processing with on-chip correlated double sampling (CDS). The imager is capable of true random pixel access with a maximum operating speed of 4MHz. The camera controller consists of a custom camera signal processor (CSP) with an integrated 16-bit A/D converter and a PowerPC-based CPU running a Linux embedded operating system. The imager is cooled to -40C via three-stage cooler to minimize dark current. The camera housing is sealed and is designed to maintain the CID820 imager in the evacuated chamber for at least 5 years. Thermo Electron has also developed custom software and firmware to drive the SpectraCAM SPM camera. Included in this firmware package is the new Extreme DRTM algorithm that is designed to extend the effective dynamic range of the camera by several orders of magnitude up to 32-bit dynamic range. The RACID Exposure graphical user interface image analysis software runs on a standard PC that is connected to the camera via Gigabit Ethernet.

A combined microphone and camera calibration technique with application to acoustic imaging.

PubMed

Legg, Mathew; Bradley, Stuart

2013-10-01

We present a calibration technique for an acoustic imaging microphone array, combined with a digital camera. Computer vision and acoustic time of arrival data are used to obtain microphone coordinates in the camera reference frame. Our new method allows acoustic maps to be plotted onto the camera images without the need for additional camera alignment or calibration. Microphones and cameras may be placed in an ad-hoc arrangement and, after calibration, the coordinates of the microphones are known in the reference frame of a camera in the array. No prior knowledge of microphone positions, inter-microphone spacings, or air temperature is required. This technique is applied to a spherical microphone array and a mean difference of 3 mm was obtained between the coordinates obtained with this calibration technique and those measured using a precision mechanical method.

Generalized assorted pixel camera: postcapture control of resolution, dynamic range, and spectrum.

PubMed

Yasuma, Fumihito; Mitsunaga, Tomoo; Iso, Daisuke; Nayar, Shree K

2010-09-01

We propose the concept of a generalized assorted pixel (GAP) camera, which enables the user to capture a single image of a scene and, after the fact, control the tradeoff between spatial resolution, dynamic range and spectral detail. The GAP camera uses a complex array (or mosaic) of color filters. A major problem with using such an array is that the captured image is severely under-sampled for at least some of the filter types. This leads to reconstructed images with strong aliasing. We make four contributions in this paper: 1) we present a comprehensive optimization method to arrive at the spatial and spectral layout of the color filter array of a GAP camera. 2) We develop a novel algorithm for reconstructing the under-sampled channels of the image while minimizing aliasing artifacts. 3) We demonstrate how the user can capture a single image and then control the tradeoff of spatial resolution to generate a variety of images, including monochrome, high dynamic range (HDR) monochrome, RGB, HDR RGB, and multispectral images. 4) Finally, the performance of our GAP camera has been verified using extensive simulations that use multispectral images of real world scenes. A large database of these multispectral images has been made available at http://www1.cs.columbia.edu/CAVE/projects/gap_camera/ for use by the research community.

Handheld hyperspectral imager system for chemical/biological and environmental applications

NASA Astrophysics Data System (ADS)

Hinnrichs, Michele; Piatek, Bob

2004-08-01

A small, hand held, battery operated imaging infrared spectrometer, Sherlock, has been developed by Pacific Advanced Technology and was field tested in early 2003. The Sherlock spectral imaging camera has been designed for remote gas leak detection, however, the architecture of the camera is versatile enough that it can be applied to numerous other applications such as homeland security, chemical/biological agent detection, medical and pharmaceutical applications as well as standard research and development. This paper describes the Sherlock camera, theory of operations, shows current applications and touches on potential future applications for the camera. The Sherlock has an embedded Power PC and performs real-time-image processing function in an embedded FPGA. The camera has a built in LCD display as well as output to a standard monitor, or NTSC display. It has several I/O ports, ethernet, firewire, RS232 and thus can be easily controlled from a remote location. In addition, software upgrades can be performed over the ethernet eliminating the need to send the camera back to the factory for a retrofit. Using the USB port a mouse and key board can be connected and the camera can be used in a laboratory environment as a stand alone imaging spectrometer.

Hand-held hyperspectral imager for chemical/biological and environmental applications

NASA Astrophysics Data System (ADS)

Hinnrichs, Michele; Piatek, Bob

2004-03-01

A small, hand held, battery operated imaging infrared spectrometer, Sherlock, has been developed by Pacific Advanced Technology and was field tested in early 2003. The Sherlock spectral imaging camera has been designed for remote gas leak detection, however, the architecture of the camera is versatile enough that it can be applied to numerous other applications such as homeland security, chemical/biological agent detection, medical and pharmaceutical applications as well as standard research and development. This paper describes the Sherlock camera, theory of operations, shows current applications and touches on potential future applications for the camera. The Sherlock has an embedded Power PC and performs real-time-image processing function in an embedded FPGA. The camera has a built in LCD display as well as output to a standard monitor, or NTSC display. It has several I/O ports, ethernet, firewire, RS232 and thus can be easily controlled from a remote location. In addition, software upgrades can be performed over the ethernet eliminating the need to send the camera back to the factory for a retrofit. Using the USB port a mouse and key board can be connected and the camera can be used in a laboratory environment as a stand alone imaging spectrometer.

Image dynamic range test and evaluation of Gaofen-2 dual cameras

NASA Astrophysics Data System (ADS)

Zhang, Zhenhua; Gan, Fuping; Wei, Dandan

2015-12-01

In order to fully understand the dynamic range of Gaofen-2 satellite data and support the data processing, application and next satellites development, in this article, we evaluated the dynamic range by calculating some statistics such as maximum ,minimum, average and stand deviation of four images obtained at the same time by Gaofen-2 dual cameras in Beijing area; then the maximum ,minimum, average and stand deviation of each longitudinal overlap of PMS1,PMS2 were calculated respectively for the evaluation of each camera's dynamic range consistency; and these four statistics of each latitudinal overlap of PMS1,PMS2 were calculated respectively for the evaluation of the dynamic range consistency between PMS1 and PMS2 at last. The results suggest that there is a wide dynamic range of DN value in the image obtained by PMS1 and PMS2 which contains rich information of ground objects; in general, the consistency of dynamic range between the single camera images is in close agreement, but also a little difference, so do the dual cameras. The consistency of dynamic range between the single camera images is better than the dual cameras'.

Digital micromirror device camera with per-pixel coded exposure for high dynamic range imaging.

PubMed

Feng, Wei; Zhang, Fumin; Wang, Weijing; Xing, Wei; Qu, Xinghua

2017-05-01

In this paper, we overcome the limited dynamic range of the conventional digital camera, and propose a method of realizing high dynamic range imaging (HDRI) from a novel programmable imaging system called a digital micromirror device (DMD) camera. The unique feature of the proposed new method is that the spatial and temporal information of incident light in our DMD camera can be flexibly modulated, and it enables the camera pixels always to have reasonable exposure intensity by DMD pixel-level modulation. More importantly, it allows different light intensity control algorithms used in our programmable imaging system to achieve HDRI. We implement the optical system prototype, analyze the theory of per-pixel coded exposure for HDRI, and put forward an adaptive light intensity control algorithm to effectively modulate the different light intensity to recover high dynamic range images. Via experiments, we demonstrate the effectiveness of our method and implement the HDRI on different objects.

The Limited Duty/Chief Warrant Officer Professional Guidebook

DTIC Science & Technology

1985-01-01

subsurface imaging . They plan and manage the operation of imaging commands and activities, combat camera groups and aerial reconnaissance imaging...picture and video systems used in aerial, surface and subsurface imaging . They supervise the operation of imaging commands and activities, combat camera

Test Image of Earth Rocks by Mars Camera Stereo

NASA Image and Video Library

2010-11-16

This stereo view of terrestrial rocks combines two images taken by a testing twin of the Mars Hand Lens Imager MAHLI camera on NASA Mars Science Laboratory. 3D glasses are necessary to view this image.

Spectroscopic interpretation and velocimetry analysis of fluctuations in a cylindrical plasma recorded by a fast camera

DOE Office of Scientific and Technical Information (OSTI.GOV)

Oldenbuerger, S.; Brandt, C.; Brochard, F.

2010-06-15

Fast visible imaging is used on a cylindrical magnetized argon plasma produced by thermionic discharge in the Mirabelle device. To link the information collected with the camera to a physical quantity, fast camera movies of plasma structures are compared to Langmuir probe measurements. High correlation is found between light fluctuations and plasma density fluctuations. Contributions from neutral argon and ionized argon to the overall light intensity are separated by using interference filters and a light intensifier. Light emitting transitions are shown to involve a metastable neutral argon state that can be excited by thermal plasma electrons, thus explaining the goodmore » correlation between light and density fluctuations. The propagation velocity of plasma structures is calculated by adapting velocimetry methods to the fast camera movies. The resulting estimates of instantaneous propagation velocity are in agreement with former experiments. The computation of mean velocities is discussed.« less

Spectroscopic interpretation and velocimetry analysis of fluctuations in a cylindrical plasma recorded by a fast camera

NASA Astrophysics Data System (ADS)

Oldenbürger, S.; Brandt, C.; Brochard, F.; Lemoine, N.; Bonhomme, G.

2010-06-01

Fast visible imaging is used on a cylindrical magnetized argon plasma produced by thermionic discharge in the Mirabelle device. To link the information collected with the camera to a physical quantity, fast camera movies of plasma structures are compared to Langmuir probe measurements. High correlation is found between light fluctuations and plasma density fluctuations. Contributions from neutral argon and ionized argon to the overall light intensity are separated by using interference filters and a light intensifier. Light emitting transitions are shown to involve a metastable neutral argon state that can be excited by thermal plasma electrons, thus explaining the good correlation between light and density fluctuations. The propagation velocity of plasma structures is calculated by adapting velocimetry methods to the fast camera movies. The resulting estimates of instantaneous propagation velocity are in agreement with former experiments. The computation of mean velocities is discussed.

High-frame rate multiport CCD imager and camera

NASA Astrophysics Data System (ADS)

Levine, Peter A.; Patterson, David R.; Esposito, Benjamin J.; Tower, John R.; Lawler, William B.

1993-01-01

A high frame rate visible CCD camera capable of operation up to 200 frames per second is described. The camera produces a 256 X 256 pixel image by using one quadrant of a 512 X 512 16-port, back illuminated CCD imager. Four contiguous outputs are digitally reformatted into a correct, 256 X 256 image. This paper details the architecture and timing used for the CCD drive circuits, analog processing, and the digital reformatter.

QUANTITATIVE DETECTION OF ENVIRONMENTALLY IMPORTANT DYES USING DIODE LASER/FIBER-OPTIC RAMAN

EPA Science Inventory

A compact diode laser/fiber-optic Raman spectrometer is used for quantitative detection of environmentally important dyes. This system is based on diode laser excitation at 782 mm, fiber optic probe technology, an imaging spectrometer, and state-of-the-art scientific CCD camera. ...

Controlled photomosaic map of Europa Je 15 M CMN

USGS Publications Warehouse

,

2002-01-01

This sheet is one in a series of maps of the Galilean satellites of Jupiter at a nominal scale of 1:15,000,000. This series is based on data from the Galileo Orbiter Solid-State Imaging (SSI) camera and the Voyager 1 and 2 spacecraft.

The advantages of using a Lucky Imaging camera for observations of microlensing events

NASA Astrophysics Data System (ADS)

Sajadian, Sedighe; Rahvar, Sohrab; Dominik, Martin; Hundertmark, Markus

2016-05-01

In this work, we study the advantages of using a Lucky Imaging camera for the observations of potential planetary microlensing events. Our aim is to reduce the blending effect and enhance exoplanet signals in binary lensing systems composed of an exoplanet and the corresponding parent star. We simulate planetary microlensing light curves based on present microlensing surveys and follow-up telescopes where one of them is equipped with a Lucky Imaging camera. This camera is used at the Danish 1.54-m follow-up telescope. Using a specific observational strategy, for an Earth-mass planet in the resonance regime, where the detection probability in crowded fields is smaller, Lucky Imaging observations improve the detection efficiency which reaches 2 per cent. Given the difficulty of detecting the signal of an Earth-mass planet in crowded-field imaging even in the resonance regime with conventional cameras, we show that Lucky Imaging can substantially improve the detection efficiency.

Suppressing the image smear of the vibration modulation transfer function for remote-sensing optical cameras.

PubMed

Li, Jin; Liu, Zilong; Liu, Si

2017-02-20

In on-board photographing processes of satellite cameras, the platform vibration can generate image motion, distortion, and smear, which seriously affect the image quality and image positioning. In this paper, we create a mathematical model of a vibrating modulate transfer function (VMTF) for a remote-sensing camera. The total MTF of a camera is reduced by the VMTF, which means the image quality is degraded. In order to avoid the degeneration of the total MTF caused by vibrations, we use an Mn-20Cu-5Ni-2Fe (M2052) manganese copper alloy material to fabricate a vibration-isolation mechanism (VIM). The VIM can transform platform vibration energy into irreversible thermal energy with its internal twin crystals structure. Our experiment shows the M2052 manganese copper alloy material is good enough to suppress image motion below 125 Hz, which is the vibration frequency of satellite platforms. The camera optical system has a higher MTF after suppressing the vibration of the M2052 material than before.

Digital fundus image grading with the non-mydriatic Visucam(PRO NM) versus the FF450(plus) camera in diabetic retinopathy.

PubMed

Neubauer, Aljoscha S; Rothschuh, Antje; Ulbig, Michael W; Blum, Marcus

2008-03-01

Grading diabetic retinopathy in clinical trials is frequently based on 7-field stereo photography of the fundus in diagnostic mydriasis. In terms of image quality, the FF450(plus) camera (Carl Zeiss Meditec AG, Jena, Germany) defines a high-quality reference. The aim of the study was to investigate if the fully digital fundus camera Visucam(PRO NM) could serve as an alternative in clinical trials requiring 7-field stereo photography. A total of 128 eyes of diabetes patients were enrolled in the randomized, controlled, prospective trial. Seven-field stereo photography was performed with the Visucam(PRO NM) and the FF450(plus) camera, in random order, both in diagnostic mydriasis. The resulting 256 image sets from the two camera systems were graded for retinopathy levels and image quality (on a scale of 1-5); both were anonymized and blinded to the image source. On FF450(plus) stereoscopic imaging, 20% of the patients had no or mild diabetic retinopathy (ETDRS level < or = 20) and 29% had no macular oedema. No patient had to be excluded as a result of image quality. Retinopathy level did not influence the quality of grading or of images. Excellent overall correspondence was obtained between the two fundus cameras regarding retinopathy levels (kappa 0.87) and macular oedema (kappa 0.80). In diagnostic mydriasis the image quality of the Visucam was graded slightly as better than that of the FF450(plus) (2.20 versus 2.41; p < 0.001), especially for pupils < 7 mm in mydriasis. The non-mydriatic Visucam(PRO NM) offers good image quality and is suitable as a more cost-efficient and easy-to-operate camera for applications and clinical trials requiring 7-field stereo photography.

Low dose in nuclear cardiology: state of the art in the era of new cadmium-zinc-telluride cameras.

PubMed

Acampa, Wanda; Buechel, Ronny R; Gimelli, Alessia

2016-06-01

The use of myocardial perfusion imaging has seen a tremendous growth during the last decade and has become the most commonly used non-invasive imaging tool for risk stratification in patients with suspected and known coronary artery disease. Adherence to radiation safety best practices varied significantly between laboratories but the possibility to use the new cameras in nuclear cardiology can reduce dramatically the radiation dose without losing accuracy. Moreover, the physical characteristics of ultrafast technology could be able to open new doors for the evaluation of old parameters, changing the impact of nuclear cardiology in the diagnostic strategies. Published on behalf of the European Society of Cardiology. All rights reserved. © The Author 2016. For permissions please email: journals.permissions@oup.com.

A projector calibration method for monocular structured light system based on digital image correlation

NASA Astrophysics Data System (ADS)

Feng, Zhixin

2018-02-01

Projector calibration is crucial for a camera-projector three-dimensional (3-D) structured light measurement system, which has one camera and one projector. In this paper, a novel projector calibration method is proposed based on digital image correlation. In the method, the projector is viewed as an inverse camera, and a plane calibration board with feature points is used to calibrate the projector. During the calibration processing, a random speckle pattern is projected onto the calibration board with different orientations to establish the correspondences between projector images and camera images. Thereby, dataset for projector calibration are generated. Then the projector can be calibrated using a well-established camera calibration algorithm. The experiment results confirm that the proposed method is accurate and reliable for projector calibration.

Volunteers Help Decide Where to Point Mars Camera

NASA Image and Video Library

2015-07-22

This series of images from NASA's Mars Reconnaissance Orbiter successively zooms into "spider" features -- or channels carved in the surface in radial patterns -- in the south polar region of Mars. In a new citizen-science project, volunteers will identify features like these using wide-scale images from the orbiter. Their input will then help mission planners decide where to point the orbiter's high-resolution camera for more detailed views of interesting terrain. Volunteers will start with images from the orbiter's Context Camera (CTX), which provides wide views of the Red Planet. The first two images in this series are from CTX; the top right image zooms into a portion of the image at left. The top right image highlights the geological spider features, which are carved into the terrain in the Martian spring when dry ice turns to gas. By identifying unusual features like these, volunteers will help the mission team choose targets for the orbiter's High Resolution Imaging Science Experiment (HiRISE) camera, which can reveal more detail than any other camera ever put into orbit around Mars. The final image is this series (bottom right) shows a HiRISE close-up of one of the spider features. http://photojournal.jpl.nasa.gov/catalog/PIA19823

Photometric Calibration and Image Stitching for a Large Field of View Multi-Camera System

PubMed Central

Lu, Yu; Wang, Keyi; Fan, Gongshu

2016-01-01

A new compact large field of view (FOV) multi-camera system is introduced. The camera is based on seven tiny complementary metal-oxide-semiconductor sensor modules covering over 160° × 160° FOV. Although image stitching has been studied extensively, sensor and lens differences have not been considered in previous multi-camera devices. In this study, we have calibrated the photometric characteristics of the multi-camera device. Lenses were not mounted on the sensor in the process of radiometric response calibration to eliminate the influence of the focusing effect of uniform light from an integrating sphere. Linearity range of the radiometric response, non-linearity response characteristics, sensitivity, and dark current of the camera response function are presented. The R, G, and B channels have different responses for the same illuminance. Vignetting artifact patterns have been tested. The actual luminance of the object is retrieved by sensor calibration results, and is used to blend images to make panoramas reflect the objective luminance more objectively. This compensates for the limitation of stitching images that are more realistic only through the smoothing method. The dynamic range limitation of can be resolved by using multiple cameras that cover a large field of view instead of a single image sensor with a wide-angle lens. The dynamic range is expanded by 48-fold in this system. We can obtain seven images in one shot with this multi-camera system, at 13 frames per second. PMID:27077857

Construction of a small and lightweight hyperspectral imaging system

NASA Astrophysics Data System (ADS)

Vogel, Britta; Hünniger, Dirk; Bastian, Georg

2014-05-01

The analysis of the reflected sunlight offers great opportunity to gain information about the environment, including vegetation and soil. In the case of plants the wavelength ratio of the reflected light usually undergoes a change if the state of growth or state of health changes. So the measurement of the reflected light allows drawing conclusions about the state of, amongst others, vegetation. Using a hyperspectral imaging system for data acquisition leads to a large dataset, which can be evaluated with respect to several different questions to obtain various information by one measurement. Based on commercially available plain optical components we developed a small and lightweight hyperspectral imaging system within the INTERREG IV A-Project SMART INSPECTORS. The project SMART INSPECTORS [Smart Aerial Test Rigs with Infrared Spectrometers and Radar] deals with the fusion of airborne visible and infrared imaging remote sensing instruments and wireless sensor networks for precision agriculture and environmental research. A high performance camera was required in terms of good signal, good wavelength resolution and good spatial resolution, while severe constraints of size, proportions and mass had to be met due to the intended use on small unmanned aerial vehicles. The detector was chosen to operate without additional cooling. The refractive and focusing optical components were identified by supporting works with an optical raytracing software and a self-developed program. We present details of design and construction of our camera system, test results to confirm the optical simulation predictions as well as our first measurements.

Multispectral image dissector camera flight test

NASA Technical Reports Server (NTRS)

Johnson, B. L.

1973-01-01

It was demonstrated that the multispectral image dissector camera is able to provide composite pictures of the earth surface from high altitude overflights. An electronic deflection feature was used to inject the gyro error signal into the camera for correction of aircraft motion.

On the accuracy potential of focused plenoptic camera range determination in long distance operation

NASA Astrophysics Data System (ADS)

Sardemann, Hannes; Maas, Hans-Gerd

2016-04-01

Plenoptic cameras have found increasing interest in optical 3D measurement techniques in recent years. While their basic principle is 100 years old, the development in digital photography, micro-lens fabrication technology and computer hardware has boosted the development and lead to several commercially available ready-to-use cameras. Beyond their popular option of a posteriori image focusing or total focus image generation, their basic ability of generating 3D information from single camera imagery depicts a very beneficial option for certain applications. The paper will first present some fundamentals on the design and history of plenoptic cameras and will describe depth determination from plenoptic camera image data. It will then present an analysis of the depth determination accuracy potential of plenoptic cameras. While most research on plenoptic camera accuracy so far has focused on close range applications, we will focus on mid and long ranges of up to 100 m. This range is especially relevant, if plenoptic cameras are discussed as potential mono-sensorial range imaging devices in (semi-)autonomous cars or in mobile robotics. The results show the expected deterioration of depth measurement accuracy with depth. At depths of 30-100 m, which may be considered typical in autonomous driving, depth errors in the order of 3% (with peaks up to 10-13 m) were obtained from processing small point clusters on an imaged target. Outliers much higher than these values were observed in single point analysis, stressing the necessity of spatial or spatio-temporal filtering of the plenoptic camera depth measurements. Despite these obviously large errors, a plenoptic camera may nevertheless be considered a valid option for the application fields of real-time robotics like autonomous driving or unmanned aerial and underwater vehicles, where the accuracy requirements decrease with distance.

Evaluation of Suppression of Hydroprocessed Renewable Jet (HRJ) Fuel Fires with Aqueous Film Forming Foam (AFFF)

DTIC Science & Technology

2011-07-01

cameras were installed around the test pan and an underwater GoPro ® video camera recorded the fire from below the layer of fuel. 3.2.2. Camera Images...Distribution A: Approved for public release; distribution unlimited. 3.2.3. Video Images A GoPro video camera with a wide angle lens recorded the tests...camera and the GoPro ® video camera were not used for fire suppression experiments. 3.3.2. Test Pans Two ¼-in thick stainless steel test pans were

Mapping the Apollo 17 landing site area based on Lunar Reconnaissance Orbiter Camera images and Apollo surface photography

NASA Astrophysics Data System (ADS)

Haase, I.; Oberst, J.; Scholten, F.; Wählisch, M.; Gläser, P.; Karachevtseva, I.; Robinson, M. S.

2012-05-01

Newly acquired high resolution Lunar Reconnaissance Orbiter Camera (LROC) images allow accurate determination of the coordinates of Apollo hardware, sampling stations, and photographic viewpoints. In particular, the positions from where the Apollo 17 astronauts recorded panoramic image series, at the so-called “traverse stations”, were precisely determined for traverse path reconstruction. We analyzed observations made in Apollo surface photography as well as orthorectified orbital images (0.5 m/pixel) and Digital Terrain Models (DTMs) (1.5 m/pixel and 100 m/pixel) derived from LROC Narrow Angle Camera (NAC) and Wide Angle Camera (WAC) images. Key features captured in the Apollo panoramic sequences were identified in LROC NAC orthoimages. Angular directions of these features were measured in the panoramic images and fitted to the NAC orthoimage by applying least squares techniques. As a result, we obtained the surface panoramic camera positions to within 50 cm. At the same time, the camera orientations, North azimuth angles and distances to nearby features of interest were also determined. Here, initial results are shown for traverse station 1 (northwest of Steno Crater) as well as the Apollo Lunar Surface Experiment Package (ALSEP) area.

Photography in Dermatologic Surgery: Selection of an Appropriate Camera Type for a Particular Clinical Application.

PubMed

Chen, Brian R; Poon, Emily; Alam, Murad

2017-08-01

Photographs are an essential tool for the documentation and sharing of findings in dermatologic surgery, and various camera types are available. To evaluate the currently available camera types in view of the special functional needs of procedural dermatologists. Mobile phone, point and shoot, digital single-lens reflex (DSLR), digital medium format, and 3-dimensional cameras were compared in terms of their usefulness for dermatologic surgeons. For each camera type, the image quality, as well as the other practical benefits and limitations, were evaluated with reference to a set of ideal camera characteristics. Based on these assessments, recommendations were made regarding the specific clinical circumstances in which each camera type would likely be most useful. Mobile photography may be adequate when ease of use, availability, and accessibility are prioritized. Point and shoot cameras and DSLR cameras provide sufficient resolution for a range of clinical circumstances, while providing the added benefit of portability. Digital medium format cameras offer the highest image quality, with accurate color rendition and greater color depth. Three-dimensional imaging may be optimal for the definition of skin contour. The selection of an optimal camera depends on the context in which it will be used.

Depth measurements through controlled aberrations of projected patterns.

PubMed

Birch, Gabriel C; Tyo, J Scott; Schwiegerling, Jim

2012-03-12

Three-dimensional displays have become increasingly present in consumer markets. However, the ability to capture three-dimensional images in space confined environments and without major modifications to current cameras is uncommon. Our goal is to create a simple modification to a conventional camera that allows for three dimensional reconstruction. We require such an imaging system have imaging and illumination paths coincident. Furthermore, we require that any three-dimensional modification to a camera also permits full resolution 2D image capture.Here we present a method of extracting depth information with a single camera and aberrated projected pattern. A commercial digital camera is used in conjunction with a projector system with astigmatic focus to capture images of a scene. By using an astigmatic projected pattern we can create two different focus depths for horizontal and vertical features of a projected pattern, thereby encoding depth. By designing an aberrated projected pattern, we are able to exploit this differential focus in post-processing designed to exploit the projected pattern and optical system. We are able to correlate the distance of an object at a particular transverse position from the camera to ratios of particular wavelet coefficients.We present our information regarding construction, calibration, and images produced by this system. The nature of linking a projected pattern design and image processing algorithms will be discussed.

Accuracy Analysis for Automatic Orientation of a Tumbling Oblique Viewing Sensor System

NASA Astrophysics Data System (ADS)

Stebner, K.; Wieden, A.

2014-03-01

Dynamic camera systems with moving parts are difficult to handle in photogrammetric workflow, because it is not ensured that the dynamics are constant over the recording period. Minimum changes of the camera's orientation greatly influence the projection of oblique images. In this publication these effects - originating from the kinematic chain of a dynamic camera system - are analysed and validated. A member of the Modular Airborne Camera System family - MACS-TumbleCam - consisting of a vertical viewing and a tumbling oblique camera was used for this investigation. Focus is on dynamic geometric modeling and the stability of the kinematic chain. To validate the experimental findings, the determined parameters are applied to the exterior orientation of an actual aerial image acquisition campaign using MACS-TumbleCam. The quality of the parameters is sufficient for direct georeferencing of oblique image data from the orientation information of a synchronously captured vertical image dataset. Relative accuracy for the oblique data set ranges from 1.5 pixels when using all images of the image block to 0.3 pixels when using only adjacent images.

Using the Standard Deviation of a Region of Interest in an Image to Estimate Camera to Emitter Distance

PubMed Central

Cano-García, Angel E.; Lazaro, José Luis; Infante, Arturo; Fernández, Pedro; Pompa-Chacón, Yamilet; Espinoza, Felipe

2012-01-01

In this study, a camera to infrared diode (IRED) distance estimation problem was analyzed. The main objective was to define an alternative to measures depth only using the information extracted from pixel grey levels of the IRED image to estimate the distance between the camera and the IRED. In this paper, the standard deviation of the pixel grey level in the region of interest containing the IRED image is proposed as an empirical parameter to define a model for estimating camera to emitter distance. This model includes the camera exposure time, IRED radiant intensity and the distance between the camera and the IRED. An expression for the standard deviation model related to these magnitudes was also derived and calibrated using different images taken under different conditions. From this analysis, we determined the optimum parameters to ensure the best accuracy provided by this alternative. Once the model calibration had been carried out, a differential method to estimate the distance between the camera and the IRED was defined and applied, considering that the camera was aligned with the IRED. The results indicate that this method represents a useful alternative for determining the depth information. PMID:22778608

Using the standard deviation of a region of interest in an image to estimate camera to emitter distance.

PubMed

Cano-García, Angel E; Lazaro, José Luis; Infante, Arturo; Fernández, Pedro; Pompa-Chacón, Yamilet; Espinoza, Felipe

2012-01-01

In this study, a camera to infrared diode (IRED) distance estimation problem was analyzed. The main objective was to define an alternative to measures depth only using the information extracted from pixel grey levels of the IRED image to estimate the distance between the camera and the IRED. In this paper, the standard deviation of the pixel grey level in the region of interest containing the IRED image is proposed as an empirical parameter to define a model for estimating camera to emitter distance. This model includes the camera exposure time, IRED radiant intensity and the distance between the camera and the IRED. An expression for the standard deviation model related to these magnitudes was also derived and calibrated using different images taken under different conditions. From this analysis, we determined the optimum parameters to ensure the best accuracy provided by this alternative. Once the model calibration had been carried out, a differential method to estimate the distance between the camera and the IRED was defined and applied, considering that the camera was aligned with the IRED. The results indicate that this method represents a useful alternative for determining the depth information.

Autocalibration of a projector-camera system.

PubMed

Okatani, Takayuki; Deguchi, Koichiro

2005-12-01

This paper presents a method for calibrating a projector-camera system that consists of multiple projectors (or multiple poses of a single projector), a camera, and a planar screen. We consider the problem of estimating the homography between the screen and the image plane of the camera or the screen-camera homography, in the case where there is no prior knowledge regarding the screen surface that enables the direct computation of the homography. It is assumed that the pose of each projector is unknown while its internal geometry is known. Subsequently, it is shown that the screen-camera homography can be determined from only the images projected by the projectors and then obtained by the camera, up to a transformation with four degrees of freedom. This transformation corresponds to arbitrariness in choosing a two-dimensional coordinate system on the screen surface and when this coordinate system is chosen in some manner, the screen-camera homography as well as the unknown poses of the projectors can be uniquely determined. A noniterative algorithm is presented, which computes the homography from three or more images. Several experimental results on synthetic as well as real images are shown to demonstrate the effectiveness of the method.

Gate simulation of Compton Ar-Xe gamma-camera for radionuclide imaging in nuclear medicine

NASA Astrophysics Data System (ADS)

Dubov, L. Yu; Belyaev, V. N.; Berdnikova, A. K.; Bolozdynia, A. I.; Akmalova, Yu A.; Shtotsky, Yu V.

2017-01-01

Computer simulations of cylindrical Compton Ar-Xe gamma camera are described in the current report. Detection efficiency of cylindrical Ar-Xe Compton camera with internal diameter of 40 cm is estimated as1-3%that is 10-100 times higher than collimated Anger’s camera. It is shown that cylindrical Compton camera can image Tc-99m radiotracer distribution with uniform spatial resolution of 20 mm through the whole field of view.

A method and results of color calibration for the Chang'e-3 terrain camera and panoramic camera

NASA Astrophysics Data System (ADS)

Ren, Xin; Li, Chun-Lai; Liu, Jian-Jun; Wang, Fen-Fei; Yang, Jian-Feng; Liu, En-Hai; Xue, Bin; Zhao, Ru-Jin

2014-12-01

The terrain camera (TCAM) and panoramic camera (PCAM) are two of the major scientific payloads installed on the lander and rover of the Chang'e 3 mission respectively. They both use a Bayer color filter array covering CMOS sensor to capture color images of the Moon's surface. RGB values of the original images are related to these two kinds of cameras. There is an obvious color difference compared with human visual perception. This paper follows standards published by the International Commission on Illumination to establish a color correction model, designs the ground calibration experiment and obtains the color correction coefficient. The image quality has been significantly improved and there is no obvious color difference in the corrected images. Ground experimental results show that: (1) Compared with uncorrected images, the average color difference of TCAM is 4.30, which has been reduced by 62.1%. (2) The average color differences of the left and right cameras in PCAM are 4.14 and 4.16, which have been reduced by 68.3% and 67.6% respectively.

Semi-autonomous wheelchair system using stereoscopic cameras.

PubMed

Nguyen, Jordan S; Nguyen, Thanh H; Nguyen, Hung T

2009-01-01

This paper is concerned with the design and development of a semi-autonomous wheelchair system using stereoscopic cameras to assist hands-free control technologies for severely disabled people. The stereoscopic cameras capture an image from both the left and right cameras, which are then processed with a Sum of Absolute Differences (SAD) correlation algorithm to establish correspondence between image features in the different views of the scene. This is used to produce a stereo disparity image containing information about the depth of objects away from the camera in the image. A geometric projection algorithm is then used to generate a 3-Dimensional (3D) point map, placing pixels of the disparity image in 3D space. This is then converted to a 2-Dimensional (2D) depth map allowing objects in the scene to be viewed and a safe travel path for the wheelchair to be planned and followed based on the user's commands. This assistive technology utilising stereoscopic cameras has the purpose of automated obstacle detection, path planning and following, and collision avoidance during navigation. Experimental results obtained in an indoor environment displayed the effectiveness of this assistive technology.

Accuracy evaluation of optical distortion calibration by digital image correlation

NASA Astrophysics Data System (ADS)

Gao, Zeren; Zhang, Qingchuan; Su, Yong; Wu, Shangquan

2017-11-01

Due to its convenience of operation, the camera calibration algorithm, which is based on the plane template, is widely used in image measurement, computer vision and other fields. How to select a suitable distortion model is always a problem to be solved. Therefore, there is an urgent need for an experimental evaluation of the accuracy of camera distortion calibrations. This paper presents an experimental method for evaluating camera distortion calibration accuracy, which is easy to implement, has high precision, and is suitable for a variety of commonly used lens. First, we use the digital image correlation method to calculate the in-plane rigid body displacement field of an image displayed on a liquid crystal display before and after translation, as captured with a camera. Next, we use a calibration board to calibrate the camera to obtain calibration parameters which are used to correct calculation points of the image before and after deformation. The displacement field before and after correction is compared to analyze the distortion calibration results. Experiments were carried out to evaluate the performance of two commonly used industrial camera lenses for four commonly used distortion models.

The Mast Cameras and Mars Descent Imager (MARDI) for the 2009 Mars Science Laboratory

NASA Technical Reports Server (NTRS)

Malin, M. C.; Bell, J. F.; Cameron, J.; Dietrich, W. E.; Edgett, K. S.; Hallet, B.; Herkenhoff, K. E.; Lemmon, M. T.; Parker, T. J.; Sullivan, R. J.

2005-01-01

Based on operational experience gained during the Mars Exploration Rover (MER) mission, we proposed and were selected to conduct two related imaging experiments: (1) an investigation of the geology and short-term atmospheric vertical wind profile local to the Mars Science Laboratory (MSL) landing site using descent imaging, and (2) a broadly-based scientific investigation of the MSL locale employing visible and very near infra-red imaging techniques from a pair of mast-mounted, high resolution cameras. Both instruments share a common electronics design, a design also employed for the MSL Mars Hand Lens Imager (MAHLI) [1]. The primary differences between the cameras are in the nature and number of mechanisms and specific optics tailored to each camera s requirements.

IMAGE Mission Science

NASA Technical Reports Server (NTRS)

Gallagher, D. L.; Fok, M.-C.; Fuselier, S.; Gladstone, G. R.; Green, J. L.; Fung, S. F.; Perez, J.; Reiff, P.; Roelof, E. C.; Wilson, G.

1998-01-01

Simultaneous, global measurement of major magnetospheric plasma systems will be performed for the first time with the Imager for Magnetopause-to-Aurora Global Exploration (IMAGE) Mission. The ring current, plasmasphere, and auroral systems will be imaged using energetic neutral and ultraviolet cameras. Quantitative remote measurement of the magnetosheath, plasmaspheric, and magnetospheric densities will be obtained through radio sounding by the Radio Plasma Imager. The IMAGE Mission will open a new era in global magnetospheric physics, while bringing with it new challenges in data analysis. An overview of the IMAGE Theory and Modeling team efforts will be presented, including the state of development of Internet tools that will be available to the science community for access and analysis of IMAGE observations.

Advances in Gamma-Ray Imaging with Intensified Quantum-Imaging Detectors

NASA Astrophysics Data System (ADS)

Han, Ling

Nuclear medicine, an important branch of modern medical imaging, is an essential tool for both diagnosis and treatment of disease. As the fundamental element of nuclear medicine imaging, the gamma camera is able to detect gamma-ray photons emitted by radiotracers injected into a patient and form an image of the radiotracer distribution, reflecting biological functions of organs or tissues. Recently, an intensified CCD/CMOS-based quantum detector, called iQID, was developed in the Center for Gamma-Ray Imaging. Originally designed as a novel type of gamma camera, iQID demonstrated ultra-high spatial resolution (< 100 micron) and many other advantages over traditional gamma cameras. This work focuses on advancing this conceptually-proven gamma-ray imaging technology to make it ready for both preclinical and clinical applications. To start with, a Monte Carlo simulation of the key light-intensification device, i.e. the image intensifier, was developed, which revealed the dominating factor(s) that limit energy resolution performance of the iQID cameras. For preclinical imaging applications, a previously-developed iQID-based single-photon-emission computed-tomography (SPECT) system, called FastSPECT III, was fully advanced in terms of data acquisition software, system sensitivity and effective FOV by developing and adopting a new photon-counting algorithm, thicker columnar scintillation detectors, and system calibration method. Originally designed for mouse brain imaging, the system is now able to provide full-body mouse imaging with sub-350-micron spatial resolution. To further advance the iQID technology to include clinical imaging applications, a novel large-area iQID gamma camera, called LA-iQID, was developed from concept to prototype. Sub-mm system resolution in an effective FOV of 188 mm x 188 mm has been achieved. The camera architecture, system components, design and integration, data acquisition, camera calibration, and performance evaluation are presented in this work. Mounted on a castered counter-weighted clinical cart, the camera also features portable and mobile capabilities for easy handling and on-site applications at remote locations where hospital facilities are not available.

Flat-panel detector, CCD cameras, and electron-beam-tube-based video for use in portal imaging

NASA Astrophysics Data System (ADS)

Roehrig, Hans; Tang, Chuankun; Cheng, Chee-Way; Dallas, William J.

1998-07-01

This paper provides a comparison of some imaging parameters of four portal imaging systems at 6 MV: a flat panel detector, two CCD cameras and an electron beam tube based video camera. Measurements were made of signal and noise and consequently of signal-to-noise per pixel as a function of the exposure. All systems have a linear response with respect to exposure, and with the exception of the electron beam tube based video camera, the noise is proportional to the square-root of the exposure, indicating photon-noise limitation. The flat-panel detector has a signal-to-noise ratio, which is higher than that observed with both CCD-Cameras or with the electron beam tube based video camera. This is expected because most portal imaging systems using optical coupling with a lens exhibit severe quantum-sinks. The measurements of signal-and noise were complemented by images of a Las Vegas-type aluminum contrast detail phantom, located at the ISO-Center. These images were generated at an exposure of 1 MU. The flat-panel detector permits detection of Aluminum holes of 1.2 mm diameter and 1.6 mm depth, indicating the best signal-to-noise ratio. The CCD-cameras rank second and third in signal-to- noise ratio, permitting detection of Aluminum-holes of 1.2 mm diameter and 2.2 mm depth (CCD_1) and of 1.2 mm diameter and 3.2 mm depth (CCD_2) respectively, while the electron beam tube based video camera permits detection of only a hole of 1.2 mm diameter and 4.6 mm depth. Rank Order Filtering was applied to the raw images from the CCD-based systems in order to remove the direct hits. These are camera responses to scattered x-ray photons which interact directly with the CCD of the CCD-Camera and generate 'Salt and Pepper type noise,' which interferes severely with attempts to determine accurate estimates of the image noise. The paper also presents data on the metal-phosphor's photon gain (the number of light-photons per interacting x-ray photon).

Artificial vision support system (AVS(2)) for improved prosthetic vision.

PubMed

Fink, Wolfgang; Tarbell, Mark A

2014-11-01

State-of-the-art and upcoming camera-driven, implanted artificial vision systems provide only tens to hundreds of electrodes, affording only limited visual perception for blind subjects. Therefore, real time image processing is crucial to enhance and optimize this limited perception. Since tens or hundreds of pixels/electrodes allow only for a very crude approximation of the typically megapixel optical resolution of the external camera image feed, the preservation and enhancement of contrast differences and transitions, such as edges, are especially important compared to picture details such as object texture. An Artificial Vision Support System (AVS(2)) is devised that displays the captured video stream in a pixelation conforming to the dimension of the epi-retinal implant electrode array. AVS(2), using efficient image processing modules, modifies the captured video stream in real time, enhancing 'present but hidden' objects to overcome inadequacies or extremes in the camera imagery. As a result, visual prosthesis carriers may now be able to discern such objects in their 'field-of-view', thus enabling mobility in environments that would otherwise be too hazardous to navigate. The image processing modules can be engaged repeatedly in a user-defined order, which is a unique capability. AVS(2) is directly applicable to any artificial vision system that is based on an imaging modality (video, infrared, sound, ultrasound, microwave, radar, etc.) as the first step in the stimulation/processing cascade, such as: retinal implants (i.e. epi-retinal, sub-retinal, suprachoroidal), optic nerve implants, cortical implants, electric tongue stimulators, or tactile stimulators.

Volumetric particle image velocimetry with a single plenoptic camera

NASA Astrophysics Data System (ADS)

Fahringer, Timothy W.; Lynch, Kyle P.; Thurow, Brian S.

2015-11-01

A novel three-dimensional (3D), three-component (3C) particle image velocimetry (PIV) technique based on volume illumination and light field imaging with a single plenoptic camera is described. A plenoptic camera uses a densely packed microlens array mounted near a high resolution image sensor to sample the spatial and angular distribution of light collected by the camera. The multiplicative algebraic reconstruction technique (MART) computed tomography algorithm is used to reconstruct a volumetric intensity field from individual snapshots and a cross-correlation algorithm is used to estimate the velocity field from a pair of reconstructed particle volumes. This work provides an introduction to the basic concepts of light field imaging with a plenoptic camera and describes the unique implementation of MART in the context of plenoptic image data for 3D/3C PIV measurements. Simulations of a plenoptic camera using geometric optics are used to generate synthetic plenoptic particle images, which are subsequently used to estimate the quality of particle volume reconstructions at various particle number densities. 3D reconstructions using this method produce reconstructed particles that are elongated by a factor of approximately 4 along the optical axis of the camera. A simulated 3D Gaussian vortex is used to test the capability of single camera plenoptic PIV to produce a 3D/3C vector field, where it was found that lateral displacements could be measured to approximately 0.2 voxel accuracy in the lateral direction and 1 voxel in the depth direction over a 300× 200× 200 voxel volume. The feasibility of the technique is demonstrated experimentally using a home-built plenoptic camera based on a 16-megapixel interline CCD camera and a 289× 193 array of microlenses and a pulsed Nd:YAG laser. 3D/3C measurements were performed in the wake of a low Reynolds number circular cylinder and compared with measurements made using a conventional 2D/2C PIV system. Overall, single camera plenoptic PIV is shown to be a viable 3D/3C velocimetry technique.

Performance evaluation and clinical applications of 3D plenoptic cameras

NASA Astrophysics Data System (ADS)

Decker, Ryan; Shademan, Azad; Opfermann, Justin; Leonard, Simon; Kim, Peter C. W.; Krieger, Axel

2015-06-01

The observation and 3D quantification of arbitrary scenes using optical imaging systems is challenging, but increasingly necessary in many fields. This paper provides a technical basis for the application of plenoptic cameras in medical and medical robotics applications, and rigorously evaluates camera integration and performance in the clinical setting. It discusses plenoptic camera calibration and setup, assesses plenoptic imaging in a clinically relevant context, and in the context of other quantitative imaging technologies. We report the methods used for camera calibration, precision and accuracy results in an ideal and simulated surgical setting. Afterwards, we report performance during a surgical task. Test results showed the average precision of the plenoptic camera to be 0.90mm, increasing to 1.37mm for tissue across the calibrated FOV. The ideal accuracy was 1.14mm. The camera showed submillimeter error during a simulated surgical task.

Micro-Imagers for Spaceborne Cell-Growth Experiments

NASA Technical Reports Server (NTRS)

Behar, Alberto; Matthews, Janet; SaintAnge, Beverly; Tanabe, Helen

2006-01-01

A document discusses selected aspects of a continuing effort to develop five micro-imagers for both still and video monitoring of cell cultures to be grown aboard the International Space Station. The approach taken in this effort is to modify and augment pre-existing electronic micro-cameras. Each such camera includes an image-detector integrated-circuit chip, signal-conditioning and image-compression circuitry, and connections for receiving power from, and exchanging data with, external electronic equipment. Four white and four multicolor light-emitting diodes are to be added to each camera for illuminating the specimens to be monitored. The lens used in the original version of each camera is to be replaced with a shorter-focal-length, more-compact singlet lens to make it possible to fit the camera into the limited space allocated to it. Initially, the lenses in the five cameras are to have different focal lengths: the focal lengths are to be 1, 1.5, 2, 2.5, and 3 cm. Once one of the focal lengths is determined to be the most nearly optimum, the remaining four cameras are to be fitted with lenses of that focal length.

High-performance camera module for fast quality inspection in industrial printing applications

NASA Astrophysics Data System (ADS)

Fürtler, Johannes; Bodenstorfer, Ernst; Mayer, Konrad J.; Brodersen, Jörg; Heiss, Dorothea; Penz, Harald; Eckel, Christian; Gravogl, Klaus; Nachtnebel, Herbert

2007-02-01

Today, printing products which must meet highest quality standards, e.g., banknotes, stamps, or vouchers, are automatically checked by optical inspection systems. Typically, the examination of fine details of the print or security features demands images taken from various perspectives, with different spectral sensitivity (visible, infrared, ultraviolet), and with high resolution. Consequently, the inspection system is equipped with several cameras and has to cope with an enormous data rate to be processed in real-time. Hence, it is desirable to move image processing tasks into the camera to reduce the amount of data which has to be transferred to the (central) image processing system. The idea is to transfer relevant information only, i.e., features of the image instead of the raw image data from the sensor. These features are then further processed. In this paper a color line-scan camera for line rates up to 100 kHz is presented. The camera is based on a commercial CMOS (complementary metal oxide semiconductor) area image sensor and a field programmable gate array (FPGA). It implements extraction of image features which are well suited to detect print flaws like blotches of ink, color smears, splashes, spots and scratches. The camera design and several image processing methods implemented on the FPGA are described, including flat field correction, compensation of geometric distortions, color transformation, as well as decimation and neighborhood operations.

Antennas for Terahertz Applications: Focal Plane Arrays and On-chip Non-contact Measurement Probes

NASA Astrophysics Data System (ADS)

Trichopoulos, Georgios C.

The terahertz (THz) band provides unique sensing opportunities that enable several important applications such as biomedical imaging, remote non-destructive inspection of packaged goods, and security screening. THz waves can penetrate most materials and can provide unique spectral information in the 0.1--10 THz band with high resolution. In contrast, other imaging modalities, like infrared (IR), suffer from low penetration depths and are thus not attractive for non-destructive evaluation. However, state-of-the-art THz imaging systems typically employ mechanical raster scans using a single detector to acquire two-dimensional images. Such devices tend to be bulky and complicated due to the mechanical parts, and are thus rather expensive to develop and operate. Thus, large-format (e.g. 100x100 pixels) and all-electronics based THz imaging systems are badly needed to alleviate the space, weight and power (SWAP) factors and enable cost effective utilization of THz waves for sensing and high-data-rate communications. In contrast, photonic sensors are very compact because light can couple directly to the photodiode without residing to radiation coupling topologies. However, in the THz band, due to the longer wavelengths and much lower photon energies, highly efficient antennas with optimized input impedance have to be integrated with THz sensors. Here, we implement novel antenna engineering techniques that are optimized to take advantage of recent technological advances in solid-state THz sensing devices. For example, large-format focal plane arrays (FPAs) have been the Achilles' heel of THz imaging systems. Typically, optical components (lenses, mirrors) are employed in order to improve the optical performance of FPAs, however, antenna sensors suffer from degraded performance when they are far from the optical axis, thus minimizing the number of useful FPA elements. By modifying the radiation pattern of FPA antennas we manage to alleviate the off-axis aberration. Additionally, a butterfly-shaped antenna layout is introduced that enables broadband imaging. The alternative design presented here, allows for video-rate imaging in the 0.6--1.2 THz band and maintains a small antenna footprint, resulting in densely packed FPAs. In both antenna designs, we optimize the impedance matching between the antennas and the integrated electronic devices, thus achieving optimum responsivity levels for high sensitivity and low noise performance. Subsequently, we present the design details of the first THz camera and the first THz camera images captured. With the realized THz camera, imaging of concealed objects is achieved with <1mm diffraction limited spatial resolution. Moreover, motivated by the THz camera's real-time image acquisition, we developed the first camera-based THz computer tomography system that allows rapid cross-sectional imaging (˜2 min). For the design and analysis of the THz camera performance, we developed an in-house hybrid electromagnetic model, combining full-wave and high-frequency computational methods. The antenna radiation and impedance computation is first carried out using full-wave modeling of the FPA. Subsequently, we employ scalar diffraction theory to compute the field distribution at any point in space. Thus, the hybrid electromagnetic model allows fast and accurate design of THz antennas and modeling of the complete THz imaging system. Finally, motivated by the novel THz antenna layouts and the quasioptical techniques, we developed a novel non-contact probe measurement method for on-chip device characterization. In the THz regime, traditional contact probes are too small and fragile, thus inhibiting accurate and reliable circuit measurements. By integrating the device under test (DUT) with THz antennas that act as the measurement probes, we may couple the incident and reflected signal from and to the network analyzer without residing to any physical connection.

Sensors for 3D Imaging: Metric Evaluation and Calibration of a CCD/CMOS Time-of-Flight Camera.

PubMed

Chiabrando, Filiberto; Chiabrando, Roberto; Piatti, Dario; Rinaudo, Fulvio

2009-01-01

3D imaging with Time-of-Flight (ToF) cameras is a promising recent technique which allows 3D point clouds to be acquired at video frame rates. However, the distance measurements of these devices are often affected by some systematic errors which decrease the quality of the acquired data. In order to evaluate these errors, some experimental tests on a CCD/CMOS ToF camera sensor, the SwissRanger (SR)-4000 camera, were performed and reported in this paper. In particular, two main aspects are treated: the calibration of the distance measurements of the SR-4000 camera, which deals with evaluation of the camera warm up time period, the distance measurement error evaluation and a study of the influence on distance measurements of the camera orientation with respect to the observed object; the second aspect concerns the photogrammetric calibration of the amplitude images delivered by the camera using a purpose-built multi-resolution field made of high contrast targets.

Real-time vehicle matching for multi-camera tunnel surveillance

NASA Astrophysics Data System (ADS)

Jelača, Vedran; Niño Castañeda, Jorge Oswaldo; Frías-Velázquez, Andrés; Pižurica, Aleksandra; Philips, Wilfried

2011-03-01

Tracking multiple vehicles with multiple cameras is a challenging problem of great importance in tunnel surveillance. One of the main challenges is accurate vehicle matching across the cameras with non-overlapping fields of view. Since systems dedicated to this task can contain hundreds of cameras which observe dozens of vehicles each, for a real-time performance computational efficiency is essential. In this paper, we propose a low complexity, yet highly accurate method for vehicle matching using vehicle signatures composed of Radon transform like projection profiles of the vehicle image. The proposed signatures can be calculated by a simple scan-line algorithm, by the camera software itself and transmitted to the central server or to the other cameras in a smart camera environment. The amount of data is drastically reduced compared to the whole image, which relaxes the data link capacity requirements. Experiments on real vehicle images, extracted from video sequences recorded in a tunnel by two distant security cameras, validate our approach.

The use of consumer depth cameras for 3D surface imaging of people with obesity: A feasibility study.

PubMed

Wheat, J S; Clarkson, S; Flint, S W; Simpson, C; Broom, D R

2018-05-21

Three dimensional (3D) surface imaging is a viable alternative to traditional body morphology measures, but the feasibility of using this technique with people with obesity has not been fully established. Therefore, the aim of this study was to investigate the validity, repeatability and acceptability of a consumer depth camera 3D surface imaging system in imaging people with obesity. The concurrent validity of the depth camera based system was investigated by comparing measures of mid-trunk volume to a gold-standard. The repeatability and acceptability of the depth camera system was assessed in people with obesity at a clinic. There was evidence of a fixed systematic difference between the depth camera system and the gold standard but excellent correlation between volume estimates (r 2 =0.997), with little evidence of proportional bias. The depth camera system was highly repeatable - low typical error (0.192L), high intraclass correlation coefficient (>0.999) and low technical error of measurement (0.64%). Depth camera based 3D surface imaging was also acceptable to people with obesity. It is feasible (valid, repeatable and acceptable) to use a low cost, flexible 3D surface imaging system to monitor the body size and shape of people with obesity in a clinical setting. Copyright © 2018 Asia Oceania Association for the Study of Obesity. Published by Elsevier Ltd. All rights reserved.

Can Commercial Digital Cameras Be Used as Multispectral Sensors? A Crop Monitoring Test.

PubMed

Lebourgeois, Valentine; Bégué, Agnès; Labbé, Sylvain; Mallavan, Benjamin; Prévot, Laurent; Roux, Bruno

2008-11-17

The use of consumer digital cameras or webcams to characterize and monitor different features has become prevalent in various domains, especially in environmental applications. Despite some promising results, such digital camera systems generally suffer from signal aberrations due to the on-board image processing systems and thus offer limited quantitative data acquisition capability. The objective of this study was to test a series of radiometric corrections having the potential to reduce radiometric distortions linked to camera optics and environmental conditions, and to quantify the effects of these corrections on our ability to monitor crop variables. In 2007, we conducted a five-month experiment on sugarcane trial plots using original RGB and modified RGB (Red-Edge and NIR) cameras fitted onto a light aircraft. The camera settings were kept unchanged throughout the acquisition period and the images were recorded in JPEG and RAW formats. These images were corrected to eliminate the vignetting effect, and normalized between acquisition dates. Our results suggest that 1) the use of unprocessed image data did not improve the results of image analyses; 2) vignetting had a significant effect, especially for the modified camera, and 3) normalized vegetation indices calculated with vignetting-corrected images were sufficient to correct for scene illumination conditions. These results are discussed in the light of the experimental protocol and recommendations are made for the use of these versatile systems for quantitative remote sensing of terrestrial surfaces.

iPhone 4s and iPhone 5s Imaging of the Eye.

PubMed

Jalil, Maaz; Ferenczy, Sandor R; Shields, Carol L

2017-01-01

To evaluate the technical feasibility of a consumer-grade cellular iPhone camera as an ocular imaging device compared to existing ophthalmic imaging equipment for documentation purposes. A comparison of iPhone 4s and 5s images was made with external facial images (macrophotography) using Nikon cameras, slit-lamp images (microphotography) using Zeiss photo slit-lamp camera, and fundus images (fundus photography) using RetCam II. In an analysis of six consecutive patients with ophthalmic conditions, both iPhones achieved documentation of external findings (macrophotography) using standard camera modality, tap to focus, and built-in flash. Both iPhones achieved documentation of anterior segment findings (microphotography) during slit-lamp examination through oculars. Both iPhones achieved fundus imaging using standard video modality with continuous iPhone illumination through an ophthalmic lens. Comparison to standard ophthalmic cameras, macrophotography and microphotography were excellent. In comparison to RetCam fundus photography, iPhone fundus photography revealed smaller field and was technically more difficult to obtain, but the quality was nearly similar to RetCam. iPhone versions 4s and 5s can provide excellent ophthalmic macrophotography and microphotography and adequate fundus photography. We believe that iPhone imaging could be most useful in settings where expensive, complicated, and cumbersome imaging equipment is unavailable.

A time-resolved image sensor for tubeless streak cameras

NASA Astrophysics Data System (ADS)

Yasutomi, Keita; Han, SangMan; Seo, Min-Woong; Takasawa, Taishi; Kagawa, Keiichiro; Kawahito, Shoji

2014-03-01

This paper presents a time-resolved CMOS image sensor with draining-only modulation (DOM) pixels for tube-less streak cameras. Although the conventional streak camera has high time resolution, the device requires high voltage and bulky system due to the structure with a vacuum tube. The proposed time-resolved imager with a simple optics realize a streak camera without any vacuum tubes. The proposed image sensor has DOM pixels, a delay-based pulse generator, and a readout circuitry. The delay-based pulse generator in combination with an in-pixel logic allows us to create and to provide a short gating clock to the pixel array. A prototype time-resolved CMOS image sensor with the proposed pixel is designed and implemented using 0.11um CMOS image sensor technology. The image array has 30(Vertical) x 128(Memory length) pixels with the pixel pitch of 22.4um. .

Plenoptic Imager for Automated Surface Navigation

NASA Technical Reports Server (NTRS)

Zollar, Byron; Milder, Andrew; Milder, Andrew; Mayo, Michael

2010-01-01

An electro-optical imaging device is capable of autonomously determining the range to objects in a scene without the use of active emitters or multiple apertures. The novel, automated, low-power imaging system is based on a plenoptic camera design that was constructed as a breadboard system. Nanohmics proved feasibility of the concept by designing an optical system for a prototype plenoptic camera, developing simulated plenoptic images and range-calculation algorithms, constructing a breadboard prototype plenoptic camera, and processing images (including range calculations) from the prototype system. The breadboard demonstration included an optical subsystem comprised of a main aperture lens, a mechanical structure that holds an array of micro lenses at the focal distance from the main lens, and a structure that mates a CMOS imaging sensor the correct distance from the micro lenses. The demonstrator also featured embedded electronics for camera readout, and a post-processor executing image-processing algorithms to provide ranging information.

Multiplane and Spectrally-Resolved Single Molecule Localization Microscopy with Industrial Grade CMOS cameras.

PubMed

Babcock, Hazen P

2018-01-29

This work explores the use of industrial grade CMOS cameras for single molecule localization microscopy (SMLM). We show that industrial grade CMOS cameras approach the performance of scientific grade CMOS cameras at a fraction of the cost. This makes it more economically feasible to construct high-performance imaging systems with multiple cameras that are capable of a diversity of applications. In particular we demonstrate the use of industrial CMOS cameras for biplane, multiplane and spectrally resolved SMLM. We also provide open-source software for simultaneous control of multiple CMOS cameras and for the reduction of the movies that are acquired to super-resolution images.

Goodman High Throughput Spectrograph | SOAR

Science.gov Websites

SPARTAN Near-IR Camera Ohio State Infrared Imager/Spectrograph (OSIRIS) - NO LONGER AVAILABLE SOAR 320-850 nm wavelength range. The paper describing the instrument is Clemens et al. (2004) Applying for IRAF. Publishing results based on Goodman data?: ADS link to 2004 SPIE Goodman Spectrograph paper

Controlled color photomosaic map of Ganymede Jg 15M CMNK

USGS Publications Warehouse

,

2003-01-01

This sheet is one in a series of maps of the Galilean satellites of Jupiter at a nominal scale of 1:15,000,000. This series is based on data from the Galileo Orbiter Solid-State Imaging (SSI) camera and the Voyager 1 and 2 spacecraft.

Space-based infrared sensors of space target imaging effect analysis

NASA Astrophysics Data System (ADS)

Dai, Huayu; Zhang, Yasheng; Zhou, Haijun; Zhao, Shuang

2018-02-01

Target identification problem is one of the core problem of ballistic missile defense system, infrared imaging simulation is an important means of target detection and recognition. This paper first established the space-based infrared sensors ballistic target imaging model of point source on the planet's atmosphere; then from two aspects of space-based sensors camera parameters and target characteristics simulated atmosphere ballistic target of infrared imaging effect, analyzed the camera line of sight jitter, camera system noise and different imaging effects of wave on the target.

Correction And Use Of Jitter In Television Images

NASA Technical Reports Server (NTRS)

Diner, Daniel B.; Fender, Derek H.; Fender, Antony R. H.

1989-01-01

Proposed system stabilizes jittering television image and/or measures jitter to extract information on motions of objects in image. Alternative version, system controls lateral motion on camera to generate stereoscopic views to measure distances to objects. In another version, motion of camera controlled to keep object in view. Heart of system is digital image-data processor called "jitter-miser", which includes frame buffer and logic circuits to correct for jitter in image. Signals from motion sensors on camera sent to logic circuits and processed into corrections for motion along and across line of sight.

A New Digital Imaging and Analysis System for Plant and Ecosystem Phenological Studies

NASA Astrophysics Data System (ADS)

Ramirez, G.; Ramirez, G. A.; Vargas, S. A., Jr.; Luna, N. R.; Tweedie, C. E.

2015-12-01

Over the past decade, environmental scientists have increasingly used low-cost sensors and custom software to gather and analyze environmental data. Included in this trend has been the use of imagery from field-mounted static digital cameras. Published literature has highlighted the challenge scientists have encountered with poor and problematic camera performance and power consumption, limited data download and wireless communication options, general ruggedness of off the shelf camera solutions, and time consuming and hard-to-reproduce digital image analysis options. Data loggers and sensors are typically limited to data storage in situ (requiring manual downloading) and/or expensive data streaming options. Here we highlight the features and functionality of a newly invented camera/data logger system and coupled image analysis software suited to plant and ecosystem phenological studies (patent pending). The camera has resulted from several years of development and prototype testing supported by several grants funded by the US NSF. These inventions have several unique features and functionality and have been field tested in desert, arctic, and tropical rainforest ecosystems. The system can be used to acquire imagery/data from static and mobile platforms. Data is collected, preprocessed, and streamed to the cloud without the need of an external computer and can run for extended time periods. The camera module is capable of acquiring RGB, IR, and thermal (LWIR) data and storing it in a variety of formats including RAW. The system is full customizable with a wide variety of passive and smart sensors. The camera can be triggered by state conditions detected by sensors and/or select time intervals. The device includes USB, Wi-Fi, Bluetooth, serial, GSM, Ethernet, and Iridium connections and can be connected to commercial cloud servers such as Dropbox. The complementary image analysis software is compatible with all popular operating systems. Imagery can be viewed and analyzed in RGB, HSV, and l*a*b color space. Users can select a spectral index, which have been derived from published literature and/or choose to have analytical output reported as separate channel strengths for a given color space. Results of the analysis can be viewed in a plot and/or saved as a .csv file for additional analysis and visualization.

Relative Panoramic Camera Position Estimation for Image-Based Virtual Reality Networks in Indoor Environments

NASA Astrophysics Data System (ADS)

Nakagawa, M.; Akano, K.; Kobayashi, T.; Sekiguchi, Y.

2017-09-01

Image-based virtual reality (VR) is a virtual space generated with panoramic images projected onto a primitive model. In imagebased VR, realistic VR scenes can be generated with lower rendering cost, and network data can be described as relationships among VR scenes. The camera network data are generated manually or by an automated procedure using camera position and rotation data. When panoramic images are acquired in indoor environments, network data should be generated without Global Navigation Satellite Systems (GNSS) positioning data. Thus, we focused on image-based VR generation using a panoramic camera in indoor environments. We propose a methodology to automate network data generation using panoramic images for an image-based VR space. We verified and evaluated our methodology through five experiments in indoor environments, including a corridor, elevator hall, room, and stairs. We confirmed that our methodology can automatically reconstruct network data using panoramic images for image-based VR in indoor environments without GNSS position data.

Fluorescent image tracking velocimeter

DOEpatents

Shaffer, Franklin D.

1994-01-01

A multiple-exposure fluorescent image tracking velocimeter (FITV) detects and measures the motion (trajectory, direction and velocity) of small particles close to light scattering surfaces. The small particles may follow the motion of a carrier medium such as a liquid, gas or multi-phase mixture, allowing the motion of the carrier medium to be observed, measured and recorded. The main components of the FITV include: (1) fluorescent particles; (2) a pulsed fluorescent excitation laser source; (3) an imaging camera; and (4) an image analyzer. FITV uses fluorescing particles excited by visible laser light to enhance particle image detectability near light scattering surfaces. The excitation laser light is filtered out before reaching the imaging camera allowing the fluoresced wavelengths emitted by the particles to be detected and recorded by the camera. FITV employs multiple exposures of a single camera image by pulsing the excitation laser light for producing a series of images of each particle along its trajectory. The time-lapsed image may be used to determine trajectory and velocity and the exposures may be coded to derive directional information.

The Moon's North Pole

NASA Image and Video Library

2017-12-08

NASA image release September 7, 2011 The Earth's moon has been an endless source of fascination for humanity for thousands of years. When at last Apollo 11 landed on the moon's surface in 1969, the crew found a desolate, lifeless orb, but one which still fascinates scientist and non-scientist alike. This image of the moon's north polar region was taken by the Lunar Reconnaissance Orbiter Camera, or LROC. One of the primary scientific objectives of LROC is to identify regions of permanent shadow and near-permanent illumination. Since the start of the mission, LROC has acquired thousands of Wide Angle Camera images approaching the north pole. From these images, scientists produced this mosaic, which is composed of 983 images taken over a one month period during northern summer. This mosaic shows the pole when it is best illuminated, regions that are in shadow are candidates for permanent shadow. Image Credit: NASA/GSFC/Arizona State University NASA Goddard Space Flight Center enables NASA’s mission through four scientific endeavors: Earth Science, Heliophysics, Solar System Exploration, and Astrophysics. Goddard plays a leading role in NASA’s accomplishments by contributing compelling scientific knowledge to advance the Agency’s mission. Follow us on Twitter Like us on Facebook Find us on Instagram

HERCULES/MSI: a multispectral imager with geolocation for STS-70

NASA Astrophysics Data System (ADS)

Simi, Christopher G.; Kindsfather, Randy; Pickard, Henry; Howard, William, III; Norton, Mark C.; Dixon, Roberta

1995-11-01

A multispectral intensified CCD imager combined with a ring laser gyroscope based inertial measurement unit was flown on the Space Shuttle Discovery from July 13-22, 1995 (Space Transport System Flight No. 70, STS-70). The camera includes a six position filter wheel, a third generation image intensifier, and a CCD camera. The camera is integrated with a laser gyroscope system that determines the ground position of the imagery to an accuracy of better than three nautical miles. The camera has two modes of operation; a panchromatic mode for high-magnification imaging [ground sample distance (GSD) of 4 m], or a multispectral mode consisting of six different user-selectable spectral ranges at reduced magnification (12 m GSD). This paper discusses the system hardware and technical trade-offs involved with camera optimization, and presents imagery observed during the shuttle mission.

Investigation into the use of photoanthropometry in facial image comparison.

PubMed

Moreton, Reuben; Morley, Johanna

2011-10-10

Photoanthropometry is a metric based facial image comparison technique. Measurements of the face are taken from an image using predetermined facial landmarks. Measurements are then converted to proportionality indices (PIs) and compared to PIs from another facial image. Photoanthropometry has been presented as a facial image comparison technique in UK courts for over 15 years. It is generally accepted that extrinsic factors (e.g. orientation of the head, camera angle and distance from the camera) can cause discrepancies in anthropometric measurements of the face from photographs. However there has been limited empirical research into quantifying the influence of such variables. The aim of this study was to determine the reliability of photoanthropometric measurements between different images of the same individual taken with different angulations of the camera. The study examined the facial measurements of 25 individuals from high resolution photographs, taken at different horizontal and vertical camera angles in a controlled environment. Results show that the degree of variability in facial measurements of the same individual due to variations in camera angle can be as great as the variability of facial measurements between different individuals. Results suggest that photoanthropometric facial comparison, as it is currently practiced, is unsuitable for elimination purposes. Preliminary investigations into the effects of distance from camera and image resolution in poor quality images suggest that such images are not an accurate representation of an individuals face, however further work is required. Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.

Joint estimation of high resolution images and depth maps from light field cameras

NASA Astrophysics Data System (ADS)

Ohashi, Kazuki; Takahashi, Keita; Fujii, Toshiaki

2014-03-01

Light field cameras are attracting much attention as tools for acquiring 3D information of a scene through a single camera. The main drawback of typical lenselet-based light field cameras is the limited resolution. This limitation comes from the structure where a microlens array is inserted between the sensor and the main lens. The microlens array projects 4D light field on a single 2D image sensor at the sacrifice of the resolution; the angular resolution and the position resolution trade-off under the fixed resolution of the image sensor. This fundamental trade-off remains after the raw light field image is converted to a set of sub-aperture images. The purpose of our study is to estimate a higher resolution image from low resolution sub-aperture images using a framework of super-resolution reconstruction. In this reconstruction, these sub-aperture images should be registered as accurately as possible. This registration is equivalent to depth estimation. Therefore, we propose a method where super-resolution and depth refinement are performed alternatively. Most of the process of our method is implemented by image processing operations. We present several experimental results using a Lytro camera, where we increased the resolution of a sub-aperture image by three times horizontally and vertically. Our method can produce clearer images compared to the original sub-aperture images and the case without depth refinement.

A novel super-resolution camera model

NASA Astrophysics Data System (ADS)

Shao, Xiaopeng; Wang, Yi; Xu, Jie; Wang, Lin; Liu, Fei; Luo, Qiuhua; Chen, Xiaodong; Bi, Xiangli

2015-05-01

Aiming to realize super resolution(SR) to single image and video reconstruction, a super resolution camera model is proposed for the problem that the resolution of the images obtained by traditional cameras behave comparatively low. To achieve this function we put a certain driving device such as piezoelectric ceramics in the camera. By controlling the driving device, a set of continuous low resolution(LR) images can be obtained and stored instantaneity, which reflect the randomness of the displacements and the real-time performance of the storage very well. The low resolution image sequences have different redundant information and some particular priori information, thus it is possible to restore super resolution image factually and effectively. The sample method is used to derive the reconstruction principle of super resolution, which analyzes the possible improvement degree of the resolution in theory. The super resolution algorithm based on learning is used to reconstruct single image and the variational Bayesian algorithm is simulated to reconstruct the low resolution images with random displacements, which models the unknown high resolution image, motion parameters and unknown model parameters in one hierarchical Bayesian framework. Utilizing sub-pixel registration method, a super resolution image of the scene can be reconstructed. The results of 16 images reconstruction show that this camera model can increase the image resolution to 2 times, obtaining images with higher resolution in currently available hardware levels.

Mitigation of Atmospheric Effects on Imaging Systems

DTIC Science & Technology

2004-03-31

focal length. The imaging system had two cameras: an Electrim camera sensitive in the visible (0.6 µ m) waveband and an Amber QWIP infrared camera...sensitive in the 9–micron region. The Amber QWIP infrared camera had 256x256 pixels, pixel pitch 38 mµ , focal length of 1.8 m, FOV of 5.4 x5.4 mr...each day. Unfortunately, signals from the different read ports of the Electrim camera picked up noise on their way to the digitizer, and this resulted

Imaging Emission Spectra with Handheld and Cellphone Cameras

NASA Astrophysics Data System (ADS)

Sitar, David

2012-12-01

As point-and-shoot digital camera technology advances it is becoming easier to image spectra in a laboralory setting on a shoestring budget and get immediale results. With this in mind, I wanted to test three cameras to see how their results would differ. Two undergraduate physics students and I used one handheld 7.1 megapixel (MP) digital Cannon point-and-shoot auto focusing camera and two different cellphone cameras: one at 6.1 MP and the other at 5.1 MP.

Use of a Digital Camera To Document Student Observations in a Microbiology Laboratory Class.

ERIC Educational Resources Information Center

Mills, David A.; Kelley, Kevin; Jones, Michael

2001-01-01

Points out the lack of microscopic images of wine-related microbes. Uses a digital camera during a wine microbiology laboratory to capture student-generated microscope images. Discusses the advantages of using a digital camera in a teaching lab. (YDS)

Lincoln Penny on Mars in Camera Calibration Target

NASA Image and Video Library

2012-09-10

The penny in this image is part of a camera calibration target on NASA Mars rover Curiosity. The MAHLI camera on the rover took this image of the MAHLI calibration target during the 34th Martian day of Curiosity work on Mars, Sept. 9, 2012.

Cheetah: A high frame rate, high resolution SWIR image camera

NASA Astrophysics Data System (ADS)

Neys, Joel; Bentell, Jonas; O'Grady, Matt; Vermeiren, Jan; Colin, Thierry; Hooylaerts, Peter; Grietens, Bob

2008-10-01

A high resolution, high frame rate InGaAs based image sensor and associated camera has been developed. The sensor and the camera are capable of recording and delivering more than 1700 full 640x512pixel frames per second. The FPA utilizes a low lag CTIA current integrator in each pixel, enabling integration times shorter than one microsecond. On-chip logics allows for four different sub windows to be read out simultaneously at even higher rates. The spectral sensitivity of the FPA is situated in the SWIR range [0.9-1.7 μm] and can be further extended into the Visible and NIR range. The Cheetah camera has max 16 GB of on-board memory to store the acquired images and transfer the data over a Gigabit Ethernet connection to the PC. The camera is also equipped with a full CameralinkTM interface to directly stream the data to a frame grabber or dedicated image processing unit. The Cheetah camera is completely under software control.

Design and fabrication of a CCD camera for use with relay optics in solar X-ray astronomy

NASA Technical Reports Server (NTRS)

1984-01-01

Configured as a subsystem of a sounding rocket experiment, a camera system was designed to record and transmit an X-ray image focused on a charge coupled device. The camera consists of a X-ray sensitive detector and the electronics for processing and transmitting image data. The design and operation of the camera are described. Schematics are included.

An image-tube camera for cometary spectrography

NASA Astrophysics Data System (ADS)

Mamadov, O.

The paper discusses the mounting of an image tube camera. The cathode is of antimony, sodium, potassium, and cesium. The parts used for mounting are of acrylic plastic and a fabric-based laminate. A mounting design that does not include cooling is presented. The aperture ratio of the camera is 1:27. Also discussed is the way that the camera is joined to the spectrograph.

Spacecraft camera image registration

NASA Technical Reports Server (NTRS)

Kamel, Ahmed A. (Inventor); Graul, Donald W. (Inventor); Chan, Fred N. T. (Inventor); Gamble, Donald W. (Inventor)

1987-01-01

A system for achieving spacecraft camera (1, 2) image registration comprises a portion external to the spacecraft and an image motion compensation system (IMCS) portion onboard the spacecraft. Within the IMCS, a computer (38) calculates an image registration compensation signal (60) which is sent to the scan control loops (84, 88, 94, 98) of the onboard cameras (1, 2). At the location external to the spacecraft, the long-term orbital and attitude perturbations on the spacecraft are modeled. Coefficients (K, A) from this model are periodically sent to the onboard computer (38) by means of a command unit (39). The coefficients (K, A) take into account observations of stars and landmarks made by the spacecraft cameras (1, 2) themselves. The computer (38) takes as inputs the updated coefficients (K, A) plus synchronization information indicating the mirror position (AZ, EL) of each of the spacecraft cameras (1, 2), operating mode, and starting and stopping status of the scan lines generated by these cameras (1, 2), and generates in response thereto the image registration compensation signal (60). The sources of periodic thermal errors on the spacecraft are discussed. The system is checked by calculating measurement residuals, the difference between the landmark and star locations predicted at the external location and the landmark and star locations as measured by the spacecraft cameras (1, 2).

Photodiode Camera Measurement of Surface Strains on Tendons during Multiple Cyclic Tests

NASA Astrophysics Data System (ADS)

Chun, Keyoung Jin; Hubbard, Robert Philip

The objectives of this study are to introduce the use of a photodiode camera for measuring surface strain on soft tissue and to present some representative responses of the tendon. Tendon specimens were obtained from the hindlimbs of canines and frozen to -70°C. After thawing, specimens were mounted in the immersion bath at a room temperature (22°C), preloaded to 0.13N and then subjected to 3% of the initial length at a strain rate of 2%/sec. In tendons which were tested in two blocks of seven repeated extensions to 3% strain with a 120 seconds wait period between, the surface strains were measured with a photodiode camera and near the gripped ends generally were greater than the surface strains in the middle segment of the tendon specimens. The recovery for peak load after the rest period was consistent but the changes in patterns of surface strains after the rest period were not consistent. The advantages of a photodiode measurement of surface strains include the followings: 1) it is a noncontacting method which eliminates errors and distortions caused by clip gauges or mechanical/electronic transducers; 2) it is more accurate than previous noncontact methods, e.g. the VDA and the high speed photographic method; 3) it is a fully automatic, thus reducing labor for replaying video tapes or films and potential errors from human judgement which can occur during digitizing data from photographs. Because the photodiode camera, employs a solid state photodiode array to sense black and white images, scan targets (black image) on the surface of the tendon specimen and back lighting system (white image), and stored automatically image data for surface strains of the tendon specimen on the computer during cyclic extensions.

Rainbow correlation imaging with macroscopic twin beam

NASA Astrophysics Data System (ADS)

Allevi, Alessia; Bondani, Maria

2017-06-01

We present the implementation of a correlation-imaging protocol that exploits both the spatial and spectral correlations of macroscopic twin-beam states generated by parametric downconversion. In particular, the spectral resolution of an imaging spectrometer coupled to an EMCCD camera is used in a proof-of-principle experiment to encrypt and decrypt a simple code to be transmitted between two parties. In order to optimize the trade-off between visibility and resolution, we provide the characterization of the correlation images as a function of the spatio-spectral properties of twin beams generated at different pump power values.

Thermodynamic free-energy minimization for unsupervised fusion of dual-color infrared breast images

NASA Astrophysics Data System (ADS)

Szu, Harold; Miao, Lidan; Qi, Hairong

2006-04-01

This paper presents algorithmic details of an unsupervised neural network and unbiased diagnostic methodology, that is, no lookup table is needed that labels the input training data with desired outputs. We deploy the smart algorithm on two satellite-grade infrared (IR) cameras. Although an early malignant tumor must be small in size and cannot be resolved by a single pixel that images about hundreds cells, these cells reveal themselves physiologically by emitting spontaneously thermal radiation due to the rapid cell growth angiogenesis effect (In Greek: vessels generation for increasing tumor blood supply), shifting toward, according to physics, a shorter IR wavelengths emission band. If we use those exceedingly sensitive IR spectral band cameras, we can in principle detect whether or not the breast tumor is perhaps malignant through a thin blouse in a close-up dark room. If this protocol turns out to be reliable in a large scale follow-on Vatican experiment in 2006, which might generate business investment interests of nano-engineering manufacture of nano-camera made of 1-D Carbon Nano-Tubes without traditional liquid Nitrogen coolant for Mid IR camera, then one can accumulate the probability of any type of malignant tumor at every pixel over time in the comfort of privacy without religious or other concerns. Such a non-intrusive protocol alone may not have enough information to make the decision, but the changes tracked over time will be surely becoming significant. Such an ill-posed inverse heat source transfer problem can be solved because of the universal constraint of equilibrium physics governing the blackbody Planck radiation distribution, to be spatio-temporally sampled. Thus, we must gather two snapshots with two IR cameras to form a vector data X(t) per pixel to invert the matrix-vector equation X=[A]S pixel-by-pixel independently, known as a single-pixel blind sources separation (BSS). Because the unknown heat transfer matrix or the impulse response function [A] may vary from the point tumor to its neighborhood, we could not rely on neighborhood statistics as did in a popular unsupervised independent component analysis (ICA) mathematical statistical method, we instead impose the physics equilibrium condition of the minimum of Helmholtz free-energy, H = E - T °S. In case of the point breast cancer, we can assume the constant ground state energy E ° to be normalized by those benign neighborhood tissue, and then the excited state can be computed by means of Taylor series expansion in terms of the pixel I/O data. We can augment the X-ray mammogram technique with passive IR imaging to reduce the unwanted X-rays during the chemotherapy recovery. When the sequence is animated into a movie, and the recovery dynamics is played backward in time, the movie simulates the cameras' potential for early detection without suffering the PD=0.1 search uncertainty. In summary, we applied two satellite-grade dual-color IR imaging cameras and advanced military (automatic target recognition) ATR spectrum fusion algorithm at the middle wavelength IR (3 - 5μm) and long wavelength IR (8 - 12μm), which are capable to screen malignant tumors proved by the time-reverse fashion of the animated movie experiments. On the contrary, the traditional thermal breast scanning/imaging, known as thermograms over decades, was IR spectrum-blind, and limited to a single night-vision camera and the necessary waiting for the cool down period for taking a second look for change detection suffers too many environmental and personnel variabilities.

Time-Domain Fluorescence Lifetime Imaging Techniques Suitable for Solid-State Imaging Sensor Arrays

PubMed Central

Li, David Day-Uei; Ameer-Beg, Simon; Arlt, Jochen; Tyndall, David; Walker, Richard; Matthews, Daniel R.; Visitkul, Viput; Richardson, Justin; Henderson, Robert K.

2012-01-01

We have successfully demonstrated video-rate CMOS single-photon avalanche diode (SPAD)-based cameras for fluorescence lifetime imaging microscopy (FLIM) by applying innovative FLIM algorithms. We also review and compare several time-domain techniques and solid-state FLIM systems, and adapt the proposed algorithms for massive CMOS SPAD-based arrays and hardware implementations. The theoretical error equations are derived and their performances are demonstrated on the data obtained from 0.13 μm CMOS SPAD arrays and the multiple-decay data obtained from scanning PMT systems. In vivo two photon fluorescence lifetime imaging data of FITC-albumin labeled vasculature of a P22 rat carcinosarcoma (BD9 rat window chamber) are used to test how different algorithms perform on bi-decay data. The proposed techniques are capable of producing lifetime images with enough contrast. PMID:22778606

Bio-Inspired Sensing and Imaging of Polarization Information in Nature

DTIC Science & Technology

2008-05-04

polarization imaging,” Appl. Opt. 36, 150–155 (1997). 5. L. B. Wolff, “Polarization camera for computer vision with a beam splitter ,” J. Opt. Soc. Am. A...vision with a beam splitter ,” J. Opt. Soc. Am. A 11, 2935–2945 (1994). 2. L. B. Wolff and A. G. Andreou, “Polarization camera sensors,” Image Vis. Comput...group we have been developing various man-made, non -invasive imaging methodologies, sensing schemes, camera systems, and visualization and display

A high-sensitivity EM-CCD camera for the open port telescope cavity of SOFIA

NASA Astrophysics Data System (ADS)

Wiedemann, Manuel; Wolf, Jürgen; McGrotty, Paul; Edwards, Chris; Krabbe, Alfred

2016-08-01

The Stratospheric Observatory for Infrared Astronomy (SOFIA) has three target acquisition and tracking cameras. All three imagers originally used the same cameras, which did not meet the sensitivity requirements, due to low quantum efficiency and high dark current. The Focal Plane Imager (FPI) suffered the most from high dark current, since it operated in the aircraft cabin at room temperatures without active cooling. In early 2013 the FPI was upgraded with an iXon3 888 from Andor Techonolgy. Compared to the original cameras, the iXon3 has a factor five higher QE, thanks to its back-illuminated sensor, and orders of magnitude lower dark current, due to a thermo-electric cooler and "inverted mode operation." This leads to an increase in sensitivity of about five stellar magnitudes. The Wide Field Imager (WFI) and Fine Field Imager (FFI) shall now be upgraded with equally sensitive cameras. However, they are exposed to stratospheric conditions in flight (typical conditions: T≍-40° C, p≍ 0:1 atm) and there are no off-the-shelf CCD cameras with the performance of an iXon3, suited for these conditions. Therefore, Andor Technology and the Deutsches SOFIA Institut (DSI) are jointly developing and qualifying a camera for these conditions, based on the iXon3 888. These changes include replacement of electrical components with MIL-SPEC or industrial grade components and various system optimizations, a new data interface that allows the image data transmission over 30m of cable from the camera to the controller, a new power converter in the camera to generate all necessary operating voltages of the camera locally and a new housing that fulfills airworthiness requirements. A prototype of this camera has been built and tested in an environmental test chamber at temperatures down to T=-62° C and pressure equivalent to 50 000 ft altitude. In this paper, we will report about the development of the camera and present results from the environmental testing.

Quantitative evaluation of the accuracy and variance of individual pixels in a scientific CMOS (sCMOS) camera for computational imaging

NASA Astrophysics Data System (ADS)

Watanabe, Shigeo; Takahashi, Teruo; Bennett, Keith

2017-02-01

The"scientific" CMOS (sCMOS) camera architecture fundamentally differs from CCD and EMCCD cameras. In digital CCD and EMCCD cameras, conversion from charge to the digital output is generally through a single electronic chain, and the read noise and the conversion factor from photoelectrons to digital outputs are highly uniform for all pixels, although quantum efficiency may spatially vary. In CMOS cameras, the charge to voltage conversion is separate for each pixel and each column has independent amplifiers and analog-to-digital converters, in addition to possible pixel-to-pixel variation in quantum efficiency. The "raw" output from the CMOS image sensor includes pixel-to-pixel variability in the read noise, electronic gain, offset and dark current. Scientific camera manufacturers digitally compensate the raw signal from the CMOS image sensors to provide usable images. Statistical noise in images, unless properly modeled, can introduce errors in methods such as fluctuation correlation spectroscopy or computational imaging, for example, localization microscopy using maximum likelihood estimation. We measured the distributions and spatial maps of individual pixel offset, dark current, read noise, linearity, photoresponse non-uniformity and variance distributions of individual pixels for standard, off-the-shelf Hamamatsu ORCA-Flash4.0 V3 sCMOS cameras using highly uniform and controlled illumination conditions, from dark conditions to multiple low light levels between 20 to 1,000 photons / pixel per frame to higher light conditions. We further show that using pixel variance for flat field correction leads to errors in cameras with good factory calibration.

Research on a solid state-streak camera based on an electro-optic crystal

NASA Astrophysics Data System (ADS)

Wang, Chen; Liu, Baiyu; Bai, Yonglin; Bai, Xiaohong; Tian, Jinshou; Yang, Wenzheng; Xian, Ouyang

2006-06-01

With excellent temporal resolution ranging from nanosecond to sub-picoseconds, a streak camera is widely utilized in measuring ultrafast light phenomena, such as detecting synchrotron radiation, examining inertial confinement fusion target, and making measurements of laser-induced discharge. In combination with appropriate optics or spectroscope, the streak camera delivers intensity vs. position (or wavelength) information on the ultrafast process. The current streak camera is based on a sweep electric pulse and an image converting tube with a wavelength-sensitive photocathode ranging from the x-ray to near infrared region. This kind of streak camera is comparatively costly and complex. This paper describes the design and performance of a new-style streak camera based on an electro-optic crystal with large electro-optic coefficient. Crystal streak camera accomplishes the goal of time resolution by direct photon beam deflection using the electro-optic effect which can replace the current streak camera from the visible to near infrared region. After computer-aided simulation, we design a crystal streak camera which has the potential of time resolution between 1ns and 10ns.Some further improvements in sweep electric circuits, a crystal with a larger electro-optic coefficient, for example LN (γ 33=33.6×10 -12m/v) and the optimal optic system may lead to better time resolution less than 1ns.

An HDR imaging method with DTDI technology for push-broom cameras

NASA Astrophysics Data System (ADS)

Sun, Wu; Han, Chengshan; Xue, Xucheng; Lv, Hengyi; Shi, Junxia; Hu, Changhong; Li, Xiangzhi; Fu, Yao; Jiang, Xiaonan; Huang, Liang; Han, Hongyin

2018-03-01

Conventionally, high dynamic-range (HDR) imaging is based on taking two or more pictures of the same scene with different exposure. However, due to a high-speed relative motion between the camera and the scene, it is hard for this technique to be applied to push-broom remote sensing cameras. For the sake of HDR imaging in push-broom remote sensing applications, the present paper proposes an innovative method which can generate HDR images without redundant image sensors or optical components. Specifically, this paper adopts an area array CMOS (complementary metal oxide semiconductor) with the digital domain time-delay-integration (DTDI) technology for imaging, instead of adopting more than one row of image sensors, thereby taking more than one picture with different exposure. And then a new HDR image by fusing two original images with a simple algorithm can be achieved. By conducting the experiment, the dynamic range (DR) of the image increases by 26.02 dB. The proposed method is proved to be effective and has potential in other imaging applications where there is a relative motion between the cameras and scenes.

Super-resolved refocusing with a plenoptic camera

NASA Astrophysics Data System (ADS)

Zhou, Zhiliang; Yuan, Yan; Bin, Xiangli; Qian, Lulu

2011-03-01

This paper presents an approach to enhance the resolution of refocused images by super resolution methods. In plenoptic imaging, we demonstrate that the raw sensor image can be divided to a number of low-resolution angular images with sub-pixel shifts between each other. The sub-pixel shift, which defines the super-resolving ability, is mathematically derived by considering the plenoptic camera as equivalent camera arrays. We implement simulation to demonstrate the imaging process of a plenoptic camera. A high-resolution image is then reconstructed using maximum a posteriori (MAP) super resolution algorithms. Without other degradation effects in simulation, the super resolved image achieves a resolution as high as predicted by the proposed model. We also build an experimental setup to acquire light fields. With traditional refocusing methods, the image is rendered at a rather low resolution. In contrast, we implement the super-resolved refocusing methods and recover an image with more spatial details. To evaluate the performance of the proposed method, we finally compare the reconstructed images using image quality metrics like peak signal to noise ratio (PSNR).

Simultaneous dual-radionuclide myocardial perfusion imaging with a solid-state dedicated cardiac camera.

PubMed

Ben-Haim, Simona; Kacperski, Krzysztof; Hain, Sharon; Van Gramberg, Dean; Hutton, Brian F; Erlandsson, Kjell; Sharir, Tali; Roth, Nathaniel; Waddington, Wendy A; Berman, Daniel S; Ell, Peter J

2010-08-01

We compared simultaneous dual-radionuclide (DR) stress and rest myocardial perfusion imaging (MPI) with a novel solid-state cardiac camera and a conventional SPECT camera with separate stress and rest acquisitions. Of 27 consecutive patients recruited, 24 (64.5+/-11.8 years of age, 16 men) were injected with 74 MBq of (201)Tl (rest) and 250 MBq (99m)Tc-MIBI (stress). Conventional MPI acquisition times for stress and rest are 21 min and 16 min, respectively. Rest (201)Tl for 6 min and simultaneous DR 15-min list mode gated scans were performed on a D-SPECT cardiac scanner. In 11 patients DR D-SPECT was performed first and in 13 patients conventional stress (99m)Tc-MIBI SPECT imaging was performed followed by DR D-SPECT. The DR D-SPECT data were processed using a spill-over and scatter correction method. DR D-SPECT images were compared with rest (201)Tl D-SPECT and with conventional SPECT images by visual analysis employing the 17-segment model and a five-point scale (0 normal, 4 absent) to calculate the summed stress and rest scores. Image quality was assessed on a four-point scale (1 poor, 4 very good) and gut activity was assessed on a four-point scale (0 none, 3 high). Conventional MPI studies were abnormal at stress in 17 patients and at rest in 9 patients. In the 17 abnormal stress studies DR D-SPECT MPI showed 113 abnormal segments and conventional MPI showed 93 abnormal segments. In the nine abnormal rest studies DR D-SPECT showed 45 abnormal segments and conventional MPI showed 48 abnormal segments. The summed stress and rest scores on conventional SPECT and DR D-SPECT were highly correlated (r=0.9790 and 0.9694, respectively). The summed scores of rest (201)Tl D-SPECT and DR-DSPECT were also highly correlated (r=0.9968, p<0.0001 for all). In six patients stress perfusion defects were significantly larger on stress DR D-SPECT images, and five of these patients were imaged earlier by D-SPECT than by conventional SPECT. Fast and high-quality simultaneous DR MPI is feasible with D-SPECT in a single imaging session with comparable diagnostic performance and image quality to conventional SPECT and to a separate rest (201)Tl D-SPECT acquisition.

Pedestrian Detection Based on Adaptive Selection of Visible Light or Far-Infrared Light Camera Image by Fuzzy Inference System and Convolutional Neural Network-Based Verification.

PubMed

Kang, Jin Kyu; Hong, Hyung Gil; Park, Kang Ryoung

2017-07-08

A number of studies have been conducted to enhance the pedestrian detection accuracy of intelligent surveillance systems. However, detecting pedestrians under outdoor conditions is a challenging problem due to the varying lighting, shadows, and occlusions. In recent times, a growing number of studies have been performed on visible light camera-based pedestrian detection systems using a convolutional neural network (CNN) in order to make the pedestrian detection process more resilient to such conditions. However, visible light cameras still cannot detect pedestrians during nighttime, and are easily affected by shadows and lighting. There are many studies on CNN-based pedestrian detection through the use of far-infrared (FIR) light cameras (i.e., thermal cameras) to address such difficulties. However, when the solar radiation increases and the background temperature reaches the same level as the body temperature, it remains difficult for the FIR light camera to detect pedestrians due to the insignificant difference between the pedestrian and non-pedestrian features within the images. Researchers have been trying to solve this issue by inputting both the visible light and the FIR camera images into the CNN as the input. This, however, takes a longer time to process, and makes the system structure more complex as the CNN needs to process both camera images. This research adaptively selects a more appropriate candidate between two pedestrian images from visible light and FIR cameras based on a fuzzy inference system (FIS), and the selected candidate is verified with a CNN. Three types of databases were tested, taking into account various environmental factors using visible light and FIR cameras. The results showed that the proposed method performs better than the previously reported methods.

Novel computer-based endoscopic camera

NASA Astrophysics Data System (ADS)

Rabinovitz, R.; Hai, N.; Abraham, Martin D.; Adler, Doron; Nissani, M.; Fridental, Ron; Vitsnudel, Ilia

1995-05-01

We have introduced a computer-based endoscopic camera which includes (a) unique real-time digital image processing to optimize image visualization by reducing over exposed glared areas and brightening dark areas, and by accentuating sharpness and fine structures, and (b) patient data documentation and management. The image processing is based on i Sight's iSP1000TM digital video processor chip and Adaptive SensitivityTM patented scheme for capturing and displaying images with wide dynamic range of light, taking into account local neighborhood image conditions and global image statistics. It provides the medical user with the ability to view images under difficult lighting conditions, without losing details `in the dark' or in completely saturated areas. The patient data documentation and management allows storage of images (approximately 1 MB per image for a full 24 bit color image) to any storage device installed into the camera, or to an external host media via network. The patient data which is included with every image described essential information on the patient and procedure. The operator can assign custom data descriptors, and can search for the stored image/data by typing any image descriptor. The camera optics has extended zoom range of f equals 20 - 45 mm allowing control of the diameter of the field which is displayed on the monitor such that the complete field of view of the endoscope can be displayed on all the area of the screen. All these features provide versatile endoscopic camera with excellent image quality and documentation capabilities.

Software for Acquiring Image Data for PIV

NASA Technical Reports Server (NTRS)

Wernet, Mark P.; Cheung, H. M.; Kressler, Brian

2003-01-01

PIV Acquisition (PIVACQ) is a computer program for acquisition of data for particle-image velocimetry (PIV). In the PIV system for which PIVACQ was developed, small particles entrained in a flow are illuminated with a sheet of light from a pulsed laser. The illuminated region is monitored by a charge-coupled-device camera that operates in conjunction with a data-acquisition system that includes a frame grabber and a counter-timer board, both installed in a single computer. The camera operates in "frame-straddle" mode where a pair of images can be obtained closely spaced in time (on the order of microseconds). The frame grabber acquires image data from the camera and stores the data in the computer memory. The counter/timer board triggers the camera and synchronizes the pulsing of the laser with acquisition of data from the camera. PIVPROC coordinates all of these functions and provides a graphical user interface, through which the user can control the PIV data-acquisition system. PIVACQ enables the user to acquire a sequence of single-exposure images, display the images, process the images, and then save the images to the computer hard drive. PIVACQ works in conjunction with the PIVPROC program which processes the images of particles into the velocity field in the illuminated plane.

A digital ISO expansion technique for digital cameras

NASA Astrophysics Data System (ADS)

Yoo, Youngjin; Lee, Kangeui; Choe, Wonhee; Park, SungChan; Lee, Seong-Deok; Kim, Chang-Yong

2010-01-01

Market's demands of digital cameras for higher sensitivity capability under low-light conditions are remarkably increasing nowadays. The digital camera market is now a tough race for providing higher ISO capability. In this paper, we explore an approach for increasing maximum ISO capability of digital cameras without changing any structure of an image sensor or CFA. Our method is directly applied to the raw Bayer pattern CFA image to avoid non-linearity characteristics and noise amplification which are usually deteriorated after ISP (Image Signal Processor) of digital cameras. The proposed method fuses multiple short exposed images which are noisy, but less blurred. Our approach is designed to avoid the ghost artifact caused by hand-shaking and object motion. In order to achieve a desired ISO image quality, both low frequency chromatic noise and fine-grain noise that usually appear in high ISO images are removed and then we modify the different layers which are created by a two-scale non-linear decomposition of an image. Once our approach is performed on an input Bayer pattern CFA image, the resultant Bayer image is further processed by ISP to obtain a fully processed RGB image. The performance of our proposed approach is evaluated by comparing SNR (Signal to Noise Ratio), MTF50 (Modulation Transfer Function), color error ~E*ab and visual quality with reference images whose exposure times are properly extended into a variety of target sensitivity.

Visual Simulation The Old Way

NASA Astrophysics Data System (ADS)

Gomes, Gary G.

1986-05-01

A cost effective and supportable color visual system has been developed to provide the necessary visual cues to United States Air Force B-52 bomber pilots training to become proficient at the task of inflight refueling. This camera model visual system approach is not suitable for all simulation applications, but provides a cost effective alternative to digital image generation systems when high fidelity of a single movable object is required. The system consists of a three axis gimballed KC-l35 tanker model, a range carriage mounted color augmented monochrome television camera, interface electronics, a color light valve projector and an infinity optics display system.

Television monitor field shifter and an opto-electronic method for obtaining a stereo image of optimal depth resolution and reduced depth distortion on a single screen

NASA Technical Reports Server (NTRS)

Diner, Daniel B. (Inventor)

1989-01-01

A method and apparatus is developed for obtaining a stereo image with reduced depth distortion and optimum depth resolution. Static and dynamic depth distortion and depth resolution tradeoff is provided. Cameras obtaining the images for a stereo view are converged at a convergence point behind the object to be presented in the image, and the collection-surface-to-object distance, the camera separation distance, and the focal lengths of zoom lenses for the cameras are all increased. Doubling the distances cuts the static depth distortion in half while maintaining image size and depth resolution. Dynamic depth distortion is minimized by panning a stereo view-collecting camera system about a circle which passes through the convergence point and the camera's first nodal points. Horizontal field shifting of the television fields on a television monitor brings both the monitor and the stereo views within the viewer's limit of binocular fusion.

Setup for testing cameras for image guided surgery using a controlled NIR fluorescence mimicking light source and tissue phantom

NASA Astrophysics Data System (ADS)

Georgiou, Giota; Verdaasdonk, Rudolf M.; van der Veen, Albert; Klaessens, John H.

2017-02-01

In the development of new near-infrared (NIR) fluorescence dyes for image guided surgery, there is a need for new NIR sensitive camera systems that can easily be adjusted to specific wavelength ranges in contrast the present clinical systems that are only optimized for ICG. To test alternative camera systems, a setup was developed to mimic the fluorescence light in a tissue phantom to measure the sensitivity and resolution. Selected narrow band NIR LED's were used to illuminate a 6mm diameter circular diffuse plate to create uniform intensity controllable light spot (μW-mW) as target/source for NIR camera's. Layers of (artificial) tissue with controlled thickness could be placed on the spot to mimic a fluorescent `cancer' embedded in tissue. This setup was used to compare a range of NIR sensitive consumer's cameras for potential use in image guided surgery. The image of the spot obtained with the cameras was captured and analyzed using ImageJ software. Enhanced CCD night vision cameras were the most sensitive capable of showing intensities < 1 μW through 5 mm of tissue. However, there was no control over the automatic gain and hence noise level. NIR sensitive DSLR cameras proved relative less sensitive but could be fully manually controlled as to gain (ISO 25600) and exposure time and are therefore preferred for a clinical setting in combination with Wi-Fi remote control. The NIR fluorescence testing setup proved to be useful for camera testing and can be used for development and quality control of new NIR fluorescence guided surgery equipment.

Design, demonstration and testing of low F-number LWIR panoramic imaging relay optics

NASA Astrophysics Data System (ADS)

Furxhi, Orges; Frascati, Joe; Driggers, Ronald

2018-04-01

Panoramic imaging is inherently wide field of view. High sensitivity uncooled Long Wave Infrared (LWIR) imaging requires low F-number optics. These two requirements result in short back working distance designs that, in addition to being costly, are challenging to integrate with commercially available uncooled LWIR cameras and cores. Common challenges include the relocation of the shutter flag, custom calibration of the camera dynamic range and NUC tables, focusing, and athermalization. Solutions to these challenges add to the system cost and make panoramic uncooled LWIR cameras commercially unattractive. In this paper, we present the design of Panoramic Imaging Relay Optics (PIRO) and show imagery and test results with one of the first prototypes. PIRO designs use several reflective surfaces (generally two) to relay a panoramic scene onto a real, donut-shaped image. The PIRO donut is imaged on the focal plane of the camera using a commercially-off-the-shelf (COTS) low F-number lens. This approach results in low component cost and effortless integration with pre-calibrated commercially available cameras and lenses.

NPS assessment of color medical image displays using a monochromatic CCD camera

NASA Astrophysics Data System (ADS)

Roehrig, Hans; Gu, Xiliang; Fan, Jiahua

2012-10-01

This paper presents an approach to Noise Power Spectrum (NPS) assessment of color medical displays without using an expensive imaging colorimeter. The R, G and B color uniform patterns were shown on the display under study and the images were taken using a high resolution monochromatic camera. A colorimeter was used to calibrate the camera images. Synthetic intensity images were formed by the weighted sum of the R, G, B and the dark screen images. Finally the NPS analysis was conducted on the synthetic images. The proposed method replaces an expensive imaging colorimeter for NPS evaluation, which also suggests a potential solution for routine color medical display QA/QC in the clinical area, especially when imaging of display devices is desired

Optimal camera exposure for video surveillance systems by predictive control of shutter speed, aperture, and gain

NASA Astrophysics Data System (ADS)

Torres, Juan; Menéndez, José Manuel

2015-02-01

This paper establishes a real-time auto-exposure method to guarantee that surveillance cameras in uncontrolled light conditions take advantage of their whole dynamic range while provide neither under nor overexposed images. State-of-the-art auto-exposure methods base their control on the brightness of the image measured in a limited region where the foreground objects are mostly located. Unlike these methods, the proposed algorithm establishes a set of indicators based on the image histogram that defines its shape and position. Furthermore, the location of the objects to be inspected is likely unknown in surveillance applications. Thus, the whole image is monitored in this approach. To control the camera settings, we defined a parameters function (Ef ) that linearly depends on the shutter speed and the electronic gain; and is inversely proportional to the square of the lens aperture diameter. When the current acquired image is not overexposed, our algorithm computes the value of Ef that would move the histogram to the maximum value that does not overexpose the capture. When the current acquired image is overexposed, it computes the value of Ef that would move the histogram to a value that does not underexpose the capture and remains close to the overexposed region. If the image is under and overexposed, the whole dynamic range of the camera is therefore used, and a default value of the Ef that does not overexpose the capture is selected. This decision follows the idea that to get underexposed images is better than to get overexposed ones, because the noise produced in the lower regions of the histogram can be removed in a post-processing step while the saturated pixels of the higher regions cannot be recovered. The proposed algorithm was tested in a video surveillance camera placed at an outdoor parking lot surrounded by buildings and trees which produce moving shadows in the ground. During the daytime of seven days, the algorithm was running alternatively together with a representative auto-exposure algorithm in the recent literature. Besides the sunrises and the nightfalls, multiple weather conditions occurred which produced light changes in the scene: sunny hours that produced sharpen shadows and highlights; cloud coverages that softened the shadows; and cloudy and rainy hours that dimmed the scene. Several indicators were used to measure the performance of the algorithms. They provided the objective quality as regards: the time that the algorithms recover from an under or over exposure, the brightness stability, and the change related to the optimal exposure. The results demonstrated that our algorithm reacts faster to all the light changes than the selected state-of-the-art algorithm. It is also capable of acquiring well exposed images and maintaining the brightness stable during more time. Summing up the results, we concluded that the proposed algorithm provides a fast and stable auto-exposure method that maintains an optimal exposure for video surveillance applications. Future work will involve the evaluation of this algorithm in robotics.

Object tracking using multiple camera video streams

NASA Astrophysics Data System (ADS)

Mehrubeoglu, Mehrube; Rojas, Diego; McLauchlan, Lifford

2010-05-01

Two synchronized cameras are utilized to obtain independent video streams to detect moving objects from two different viewing angles. The video frames are directly correlated in time. Moving objects in image frames from the two cameras are identified and tagged for tracking. One advantage of such a system involves overcoming effects of occlusions that could result in an object in partial or full view in one camera, when the same object is fully visible in another camera. Object registration is achieved by determining the location of common features in the moving object across simultaneous frames. Perspective differences are adjusted. Combining information from images from multiple cameras increases robustness of the tracking process. Motion tracking is achieved by determining anomalies caused by the objects' movement across frames in time in each and the combined video information. The path of each object is determined heuristically. Accuracy of detection is dependent on the speed of the object as well as variations in direction of motion. Fast cameras increase accuracy but limit the speed and complexity of the algorithm. Such an imaging system has applications in traffic analysis, surveillance and security, as well as object modeling from multi-view images. The system can easily be expanded by increasing the number of cameras such that there is an overlap between the scenes from at least two cameras in proximity. An object can then be tracked long distances or across multiple cameras continuously, applicable, for example, in wireless sensor networks for surveillance or navigation.

Clinical evaluation of pixellated NaI:Tl and continuous LaBr 3:Ce, compact scintillation cameras for breast tumors imaging

NASA Astrophysics Data System (ADS)

Pani, R.; Pellegrini, R.; Betti, M.; De Vincentis, G.; Cinti, M. N.; Bennati, P.; Vittorini, F.; Casali, V.; Mattioli, M.; Orsolini Cencelli, V.; Navarria, F.; Bollini, D.; Moschini, G.; Iurlaro, G.; Montani, L.; de Notaristefani, F.

2007-02-01

The principal limiting factor in the clinical acceptance of scintimammography is certainly its low sensitivity for cancers sized <1 cm, mainly due to the lack of equipment specifically designed for breast imaging. The National Institute of Nuclear Physics (INFN) has been developing a new scintillation camera based on Lanthanum tri-Bromide Cerium-doped crystal (LaBr 3:Ce), that demonstrating superior imaging performances with respect to the dedicated scintillation γ-camera that was previously developed. The proposed detector consists of continuous LaBr 3:Ce scintillator crystal coupled to a Hamamatsu H8500 Flat Panel PMT. One centimeter thick crystal has been chosen to increase crystal detection efficiency. In this paper, we propose a comparison and evaluation between lanthanum γ-camera and a Multi PSPMT camera, NaI(Tl) discrete pixel based, previously developed under "IMI" Italian project for technological transfer of INFN. A phantom study has been developed to test both the cameras before introducing them in clinical trials. High resolution scans produced by LaBr 3:Ce camera showed higher tumor contrast with a detailed imaging of uptake area than pixellated NaI(Tl) dedicated camera. Furthermore, with the lanthanum camera, the Signal-to-Noise Ratio ( SNR) value was increased for a lesion as small as 5 mm, with a consequent strong improvement in detectability.

Photogrammetric Modeling and Image-Based Rendering for Rapid Virtual Environment Creation

DTIC Science & Technology

2004-12-01

area and different methods have been proposed. Pertinent methods include: Camera Calibration , Structure from Motion, Stereo Correspondence, and Image...Based Rendering 1.1.1 Camera Calibration Determining the 3D structure of a model from multiple views becomes simpler if the intrinsic (or internal...can introduce significant nonlinearities into the image. We have found that camera calibration is a straightforward process which can simplify the

Research on inosculation between master of ceremonies or players and virtual scene in virtual studio

NASA Astrophysics Data System (ADS)

Li, Zili; Zhu, Guangxi; Zhu, Yaoting

2003-04-01

A technical principle about construction of virtual studio has been proposed where orientation tracker and telemeter has been used for improving conventional BETACAM pickup camera and connecting with the software module of the host. A model of virtual camera named Camera & Post-camera Coupling Pair has been put forward, which is different from the common model in computer graphics and has been bound to real BETACAM pickup camera for shooting. The formula has been educed to compute the foreground frame buffer image and the background frame buffer image of the virtual scene whose boundary is based on the depth information of target point of the real BETACAM pickup camera's projective ray. The effect of real-time consistency has been achieved between the video image sequences of the master of ceremonies or players and the CG video image sequences for the virtual scene in spatial position, perspective relationship and image object masking. The experimental result has shown that the technological scheme of construction of virtual studio submitted in this paper is feasible and more applicative and more effective than the existing technology to establish a virtual studio based on color-key and image synthesis with background using non-linear video editing technique.

The use of low cost compact cameras with focus stacking functionality in entomological digitization projects

PubMed Central

Mertens, Jan E.J.; Roie, Martijn Van; Merckx, Jonas; Dekoninck, Wouter

2017-01-01

Abstract Digitization of specimen collections has become a key priority of many natural history museums. The camera systems built for this purpose are expensive, providing a barrier in institutes with limited funding, and therefore hampering progress. An assessment is made on whether a low cost compact camera with image stacking functionality can help expedite the digitization process in large museums or provide smaller institutes and amateur entomologists with the means to digitize their collections. Images of a professional setup were compared with the Olympus Stylus TG-4 Tough, a low-cost compact camera with internal focus stacking functions. Parameters considered include image quality, digitization speed, price, and ease-of-use. The compact camera’s image quality, although inferior to the professional setup, is exceptional considering its fourfold lower price point. Producing the image slices in the compact camera is a matter of seconds and when optimal image quality is less of a priority, the internal stacking function omits the need for dedicated stacking software altogether, further decreasing the cost and speeding up the process. In general, it is found that, aware of its limitations, this compact camera is capable of digitizing entomological collections with sufficient quality. As technology advances, more institutes and amateur entomologists will be able to easily and affordably catalogue their specimens. PMID:29134038

From a Million Miles Away, NASA Camera Shows Moon Crossing Face of Earth

NASA Image and Video Library

2015-08-05

This animation shows images of the far side of the moon, illuminated by the sun, as it crosses between the DISCOVR spacecraft's Earth Polychromatic Imaging Camera (EPIC) camera and telescope, and the Earth - one million miles away. Credits: NASA/NOAA A NASA camera aboard the Deep Space Climate Observatory (DSCOVR) satellite captured a unique view of the moon as it moved in front of the sunlit side of Earth last month. The series of test images shows the fully illuminated “dark side” of the moon that is never visible from Earth. The images were captured by NASA’s Earth Polychromatic Imaging Camera (EPIC), a four megapixel CCD camera and telescope on the DSCOVR satellite orbiting 1 million miles from Earth. From its position between the sun and Earth, DSCOVR conducts its primary mission of real-time solar wind monitoring for the National Oceanic and Atmospheric Administration (NOAA). Read more: www.nasa.gov/feature/goddard/from-a-million-miles-away-na... NASA image use policy. NASA Goddard Space Flight Center enables NASA’s mission through four scientific endeavors: Earth Science, Heliophysics, Solar System Exploration, and Astrophysics. Goddard plays a leading role in NASA’s accomplishments by contributing compelling scientific knowledge to advance the Agency’s mission. Follow us on Twitter Like us on Facebook Find us on Instagram

From a Million Miles Away, NASA Camera Shows Moon Crossing Face of Earth

NASA Image and Video Library

2017-12-08

This animation still image shows the far side of the moon, illuminated by the sun, as it crosses between the DISCOVR spacecraft's Earth Polychromatic Imaging Camera (EPIC) camera and telescope, and the Earth - one million miles away. Credits: NASA/NOAA A NASA camera aboard the Deep Space Climate Observatory (DSCOVR) satellite captured a unique view of the moon as it moved in front of the sunlit side of Earth last month. The series of test images shows the fully illuminated “dark side” of the moon that is never visible from Earth. The images were captured by NASA’s Earth Polychromatic Imaging Camera (EPIC), a four megapixel CCD camera and telescope on the DSCOVR satellite orbiting 1 million miles from Earth. From its position between the sun and Earth, DSCOVR conducts its primary mission of real-time solar wind monitoring for the National Oceanic and Atmospheric Administration (NOAA). Read more: www.nasa.gov/feature/goddard/from-a-million-miles-away-na... NASA image use policy. NASA Goddard Space Flight Center enables NASA’s mission through four scientific endeavors: Earth Science, Heliophysics, Solar System Exploration, and Astrophysics. Goddard plays a leading role in NASA’s accomplishments by contributing compelling scientific knowledge to advance the Agency’s mission. Follow us on Twitter Like us on Facebook Find us on Instagram

Introducing the depth transfer curve for 3D capture system characterization

NASA Astrophysics Data System (ADS)

Goma, Sergio R.; Atanassov, Kalin; Ramachandra, Vikas

2011-03-01

3D technology has recently made a transition from movie theaters to consumer electronic devices such as 3D cameras and camcorders. In addition to what 2D imaging conveys, 3D content also contains information regarding the scene depth. Scene depth is simulated through the strongest brain depth cue, namely retinal disparity. This can be achieved by capturing an image by horizontally separated cameras. Objects at different depths will be projected with different horizontal displacement on the left and right camera images. These images, when fed separately to either eye, leads to retinal disparity. Since the perception of depth is the single most important 3D imaging capability, an evaluation procedure is needed to quantify the depth capture characteristics. Evaluating depth capture characteristics subjectively is a very difficult task since the intended and/or unintended side effects from 3D image fusion (depth interpretation) by the brain are not immediately perceived by the observer, nor do such effects lend themselves easily to objective quantification. Objective evaluation of 3D camera depth characteristics is an important tool that can be used for "black box" characterization of 3D cameras. In this paper we propose a methodology to evaluate the 3D cameras' depth capture capabilities.

Constructing a Database from Multiple 2D Images for Camera Pose Estimation and Robot Localization

NASA Technical Reports Server (NTRS)

Wolf, Michael; Ansar, Adnan I.; Brennan, Shane; Clouse, Daniel S.; Padgett, Curtis W.

2012-01-01

The LMDB (Landmark Database) Builder software identifies persistent image features (landmarks) in a scene viewed multiple times and precisely estimates the landmarks 3D world positions. The software receives as input multiple 2D images of approximately the same scene, along with an initial guess of the camera poses for each image, and a table of features matched pair-wise in each frame. LMDB Builder aggregates landmarks across an arbitrarily large collection of frames with matched features. Range data from stereo vision processing can also be passed to improve the initial guess of the 3D point estimates. The LMDB Builder aggregates feature lists across all frames, manages the process to promote selected features to landmarks, and iteratively calculates the 3D landmark positions using the current camera pose estimations (via an optimal ray projection method), and then improves the camera pose estimates using the 3D landmark positions. Finally, it extracts image patches for each landmark from auto-selected key frames and constructs the landmark database. The landmark database can then be used to estimate future camera poses (and therefore localize a robotic vehicle that may be carrying the cameras) by matching current imagery to landmark database image patches and using the known 3D landmark positions to estimate the current pose.

Using DSLR cameras in digital holography

NASA Astrophysics Data System (ADS)

Hincapié-Zuluaga, Diego; Herrera-Ramírez, Jorge; García-Sucerquia, Jorge

2017-08-01

In Digital Holography (DH), the size of the bidimensional image sensor to record the digital hologram, plays a key role on the performance of this imaging technique; the larger the size of the camera sensor, the better the quality of the final reconstructed image. Scientific cameras with large formats are offered in the market, but their cost and availability limit their use as a first option when implementing DH. Nowadays, DSLR cameras provide an easy-access alternative that is worthwhile to be explored. The DSLR cameras are a wide, commercial, and available option that in comparison with traditional scientific cameras, offer a much lower cost per effective pixel over a large sensing area. However, in the DSLR cameras, with their RGB pixel distribution, the sampling of information is different to the sampling in monochrome cameras usually employed in DH. This fact has implications in their performance. In this work, we discuss why DSLR cameras are not extensively used for DH, taking into account the problem reported by different authors of object replication. Simulations of DH using monochromatic and DSLR cameras are presented and a theoretical deduction for the replication problem using the Fourier theory is also shown. Experimental results of DH implementation using a DSLR camera show the replication problem.

Evaluation of Real-Time Hand Motion Tracking Using a Range Camera and the Mean-Shift Algorithm

NASA Astrophysics Data System (ADS)

Lahamy, H.; Lichti, D.

2011-09-01

Several sensors have been tested for improving the interaction between humans and machines including traditional web cameras, special gloves, haptic devices, cameras providing stereo pairs of images and range cameras. Meanwhile, several methods are described in the literature for tracking hand motion: the Kalman filter, the mean-shift algorithm and the condensation algorithm. In this research, the combination of a range camera and the simple version of the mean-shift algorithm has been evaluated for its capability for hand motion tracking. The evaluation was assessed in terms of position accuracy of the tracking trajectory in x, y and z directions in the camera space and the time difference between image acquisition and image display. Three parameters have been analyzed regarding their influence on the tracking process: the speed of the hand movement, the distance between the camera and the hand and finally the integration time of the camera. Prior to the evaluation, the required warm-up time of the camera has been measured. This study has demonstrated the suitability of the range camera used in combination with the mean-shift algorithm for real-time hand motion tracking but for very high speed hand movement in the traverse plane with respect to the camera, the tracking accuracy is low and requires improvement.

Geometrical Calibration of the Photo-Spectral System and Digital Maps Retrieval

NASA Astrophysics Data System (ADS)

Bruchkouskaya, S.; Skachkova, A.; Katkovski, L.; Martinov, A.

2013-12-01

Imaging systems for remote sensing of the Earth are required to demonstrate high metric accuracy of the picture which can be provided through preliminary geometrical calibration of optical systems. Being defined as a result of the geometrical calibration, parameters of internal and external orientation of the cameras are needed while solving such problems of image processing, as orthotransformation, geometrical correction, geographical coordinate fixing, scale adjustment and image registration from various channels and cameras, creation of image mosaics of filmed territories, and determination of geometrical characteristics of objects in the images. The geometrical calibration also helps to eliminate image deformations arising due to manufacturing defects and errors in installation of camera elements and photo receiving matrices as well as those resulted from lens distortions. A Photo-Spectral System (PhSS), which is intended for registering reflected radiation spectra of underlying surfaces in a wavelength range from 350 nm to 1050 nm and recording images of high spatial resolution, has been developed at the A.N. Sevchenko Research Institute of Applied Physical Problems of the Belarusian State University. The PhSS has undergone flight tests over the territory of Belarus onboard the Antonov AN-2 aircraft with the aim to obtain visible range images of the underlying surface. Then we performed the geometrical calibration of the PhSS and carried out the correction of images obtained during the flight tests. Furthermore, we have plotted digital maps of the terrain using the stereo pairs of images acquired from the PhSS and evaluated the accuracy of the created maps. Having obtained the calibration parameters, we apply them for correction of the images from another identical PhSS device, which is located at the Russian Orbital Segment of the International Space Station (ROS ISS), aiming to retrieve digital maps of the terrain with higher accuracy.

Technology and Technique Standards for Camera-Acquired Digital Dermatologic Images: A Systematic Review.

PubMed

Quigley, Elizabeth A; Tokay, Barbara A; Jewell, Sarah T; Marchetti, Michael A; Halpern, Allan C

2015-08-01

Photographs are invaluable dermatologic diagnostic, management, research, teaching, and documentation tools. Digital Imaging and Communications in Medicine (DICOM) standards exist for many types of digital medical images, but there are no DICOM standards for camera-acquired dermatologic images to date. To identify and describe existing or proposed technology and technique standards for camera-acquired dermatologic images in the scientific literature. Systematic searches of the PubMed, EMBASE, and Cochrane databases were performed in January 2013 using photography and digital imaging, standardization, and medical specialty and medical illustration search terms and augmented by a gray literature search of 14 websites using Google. Two reviewers independently screened titles of 7371 unique publications, followed by 3 sequential full-text reviews, leading to the selection of 49 publications with the most recent (1985-2013) or detailed description of technology or technique standards related to the acquisition or use of images of skin disease (or related conditions). No universally accepted existing technology or technique standards for camera-based digital images in dermatology were identified. Recommendations are summarized for technology imaging standards, including spatial resolution, color resolution, reproduction (magnification) ratios, postacquisition image processing, color calibration, compression, output, archiving and storage, and security during storage and transmission. Recommendations are also summarized for technique imaging standards, including environmental conditions (lighting, background, and camera position), patient pose and standard view sets, and patient consent, privacy, and confidentiality. Proposed standards for specific-use cases in total body photography, teledermatology, and dermoscopy are described. The literature is replete with descriptions of obtaining photographs of skin disease, but universal imaging standards have not been developed, validated, and adopted to date. Dermatologic imaging is evolving without defined standards for camera-acquired images, leading to variable image quality and limited exchangeability. The development and adoption of universal technology and technique standards may first emerge in scenarios when image use is most associated with a defined clinical benefit.

Super-resolved all-refocused image with a plenoptic camera

NASA Astrophysics Data System (ADS)

Wang, Xiang; Li, Lin; Hou, Guangqi

2015-12-01

This paper proposes an approach to produce the super-resolution all-refocused images with the plenoptic camera. The plenoptic camera can be produced by putting a micro-lens array between the lens and the sensor in a conventional camera. This kind of camera captures both the angular and spatial information of the scene in one single shot. A sequence of digital refocused images, which are refocused at different depth, can be produced after processing the 4D light field captured by the plenoptic camera. The number of the pixels in the refocused image is the same as that of the micro-lens in the micro-lens array. Limited number of the micro-lens will result in poor low resolution refocused images. Therefore, not enough details will exist in these images. Such lost details, which are often high frequency information, are important for the in-focus part in the refocused image. We decide to super-resolve these in-focus parts. The result of image segmentation method based on random walks, which works on the depth map produced from the 4D light field data, is used to separate the foreground and background in the refocused image. And focusing evaluation function is employed to determine which refocused image owns the clearest foreground part and which one owns the clearest background part. Subsequently, we employ single image super-resolution method based on sparse signal representation to process the focusing parts in these selected refocused images. Eventually, we can obtain the super-resolved all-focus image through merging the focusing background part and the focusing foreground part in the way of digital signal processing. And more spatial details will be kept in these output images. Our method will enhance the resolution of the refocused image, and just the refocused images owning the clearest foreground and background need to be super-resolved.

A Semi-Automatic Image-Based Close Range 3D Modeling Pipeline Using a Multi-Camera Configuration

PubMed Central

Rau, Jiann-Yeou; Yeh, Po-Chia

2012-01-01

The generation of photo-realistic 3D models is an important task for digital recording of cultural heritage objects. This study proposes an image-based 3D modeling pipeline which takes advantage of a multi-camera configuration and multi-image matching technique that does not require any markers on or around the object. Multiple digital single lens reflex (DSLR) cameras are adopted and fixed with invariant relative orientations. Instead of photo-triangulation after image acquisition, calibration is performed to estimate the exterior orientation parameters of the multi-camera configuration which can be processed fully automatically using coded targets. The calibrated orientation parameters of all cameras are applied to images taken using the same camera configuration. This means that when performing multi-image matching for surface point cloud generation, the orientation parameters will remain the same as the calibrated results, even when the target has changed. Base on this invariant character, the whole 3D modeling pipeline can be performed completely automatically, once the whole system has been calibrated and the software was seamlessly integrated. Several experiments were conducted to prove the feasibility of the proposed system. Images observed include that of a human being, eight Buddhist statues, and a stone sculpture. The results for the stone sculpture, obtained with several multi-camera configurations were compared with a reference model acquired by an ATOS-I 2M active scanner. The best result has an absolute accuracy of 0.26 mm and a relative accuracy of 1:17,333. It demonstrates the feasibility of the proposed low-cost image-based 3D modeling pipeline and its applicability to a large quantity of antiques stored in a museum. PMID:23112656

Development of an Ultra-Violet Digital Camera for Volcanic Sulfur Dioxide Imaging

NASA Astrophysics Data System (ADS)

Bluth, G. J.; Shannon, J. M.; Watson, I. M.; Prata, F. J.; Realmuto, V. J.

2006-12-01

In an effort to improve monitoring of passive volcano degassing, we have constructed and tested a digital camera for quantifying the sulfur dioxide (SO2) content of volcanic plumes. The camera utilizes a bandpass filter to collect photons in the ultra-violet (UV) region where SO2 selectively absorbs UV light. SO2 is quantified by imaging calibration cells of known SO2 concentrations. Images of volcanic SO2 plumes were collected at four active volcanoes with persistent passive degassing: Villarrica, located in Chile, and Santiaguito, Fuego, and Pacaya, located in Guatemala. Images were collected from distances ranging between 4 and 28 km away, with crisp detection up to approximately 16 km. Camera set-up time in the field ranges from 5-10 minutes and images can be recorded in as rapidly as 10-second intervals. Variable in-plume concentrations can be observed and accurate plume speeds (or rise rates) can readily be determined by tracing individual portions of the plume within sequential images. Initial fluxes computed from camera images require a correction for the effects of environmental light scattered into the field of view. At Fuego volcano, simultaneous measurements of corrected SO2 fluxes with the camera and a Correlation Spectrometer (COSPEC) agreed within 25 percent. Experiments at the other sites were equally encouraging, and demonstrated the camera's ability to detect SO2 under demanding meteorological conditions. This early work has shown great success in imaging SO2 plumes and offers promise for volcano monitoring due to its rapid deployment and data processing capabilities, relatively low cost, and improved interpretation afforded by synoptic plume coverage from a range of distances.

A semi-automatic image-based close range 3D modeling pipeline using a multi-camera configuration.

PubMed

Rau, Jiann-Yeou; Yeh, Po-Chia

2012-01-01

The generation of photo-realistic 3D models is an important task for digital recording of cultural heritage objects. This study proposes an image-based 3D modeling pipeline which takes advantage of a multi-camera configuration and multi-image matching technique that does not require any markers on or around the object. Multiple digital single lens reflex (DSLR) cameras are adopted and fixed with invariant relative orientations. Instead of photo-triangulation after image acquisition, calibration is performed to estimate the exterior orientation parameters of the multi-camera configuration which can be processed fully automatically using coded targets. The calibrated orientation parameters of all cameras are applied to images taken using the same camera configuration. This means that when performing multi-image matching for surface point cloud generation, the orientation parameters will remain the same as the calibrated results, even when the target has changed. Base on this invariant character, the whole 3D modeling pipeline can be performed completely automatically, once the whole system has been calibrated and the software was seamlessly integrated. Several experiments were conducted to prove the feasibility of the proposed system. Images observed include that of a human being, eight Buddhist statues, and a stone sculpture. The results for the stone sculpture, obtained with several multi-camera configurations were compared with a reference model acquired by an ATOS-I 2M active scanner. The best result has an absolute accuracy of 0.26 mm and a relative accuracy of 1:17,333. It demonstrates the feasibility of the proposed low-cost image-based 3D modeling pipeline and its applicability to a large quantity of antiques stored in a museum.

Optimized algorithm for the spatial nonuniformity correction of an imaging system based on a charge-coupled device color camera.

PubMed

de Lasarte, Marta; Pujol, Jaume; Arjona, Montserrat; Vilaseca, Meritxell

2007-01-10

We present an optimized linear algorithm for the spatial nonuniformity correction of a CCD color camera's imaging system and the experimental methodology developed for its implementation. We assess the influence of the algorithm's variables on the quality of the correction, that is, the dark image, the base correction image, and the reference level, and the range of application of the correction using a uniform radiance field provided by an integrator cube. The best spatial nonuniformity correction is achieved by having a nonzero dark image, by using an image with a mean digital level placed in the linear response range of the camera as the base correction image and taking the mean digital level of the image as the reference digital level. The response of the CCD color camera's imaging system to the uniform radiance field shows a high level of spatial uniformity after the optimized algorithm has been applied, which also allows us to achieve a high-quality spatial nonuniformity correction of captured images under different exposure conditions.

Performance evaluation of low-cost airglow cameras for mesospheric gravity wave measurements

NASA Astrophysics Data System (ADS)

Suzuki, S.; Shiokawa, K.

2016-12-01

Atmospheric gravity waves significantly contribute to the wind/thermal balances in the mesosphere and lower thermosphere (MLT) through their vertical transport of horizontal momentum. It has been reported that the gravity wave momentum flux preferentially associated with the scale of the waves; the momentum fluxes of the waves with a horizontal scale of 10-100 km are particularly significant. Airglow imaging is a useful technique to observe two-dimensional structure of small-scale (<100 km) gravity waves in the MLT region and has been used to investigate global behaviour of the waves. Recent studies with simultaneous/multiple airglow cameras have derived spatial extent of the MLT waves. Such network imaging observations are advantageous to ever better understanding of coupling between the lower and upper atmosphere via gravity waves. In this study, we newly developed low-cost airglow cameras to enlarge the airglow imaging network. Each of the cameras has a fish-eye lens with a 185-deg field-of-view and equipped with a CCD video camera (WATEC WAT-910HX) ; the camera is small (W35.5 x H36.0 x D63.5 mm) and inexpensive, much more than the airglow camera used for the existing ground-based network (Optical Mesosphere Thermosphere Imagers (OMTI) operated by Solar-Terrestrial Environmental Laboratory, Nagoya University), and has a CCD sensor with 768 x 494 pixels that is highly sensitive enough to detect the mesospheric OH airglow emission perturbations. In this presentation, we will report some results of performance evaluation of this camera made at Shigaraki (35-deg N, 136-deg E), Japan, where is one of the OMTI station. By summing 15-images (i.e., 1-min composition of the images) we recognised clear gravity wave patterns in the images with comparable quality to the OMTI's image. Outreach and educational activities based on this research will be also reported.

Digital Camera Control for Faster Inspection

NASA Technical Reports Server (NTRS)

Brown, Katharine; Siekierski, James D.; Mangieri, Mark L.; Dekome, Kent; Cobarruvias, John; Piplani, Perry J.; Busa, Joel

2009-01-01

Digital Camera Control Software (DCCS) is a computer program for controlling a boom and a boom-mounted camera used to inspect the external surface of a space shuttle in orbit around the Earth. Running in a laptop computer in the space-shuttle crew cabin, DCCS commands integrated displays and controls. By means of a simple one-button command, a crewmember can view low- resolution images to quickly spot problem areas and can then cause a rapid transition to high- resolution images. The crewmember can command that camera settings apply to a specific small area of interest within the field of view of the camera so as to maximize image quality within that area. DCCS also provides critical high-resolution images to a ground screening team, which analyzes the images to assess damage (if any); in so doing, DCCS enables the team to clear initially suspect areas more quickly than would otherwise be possible and further saves time by minimizing the probability of re-imaging of areas already inspected. On the basis of experience with a previous version (2.0) of the software, the present version (3.0) incorporates a number of advanced imaging features that optimize crewmember capability and efficiency.

Dense Region of Impact Craters

NASA Image and Video Library

2011-09-23

NASA Dawn spacecraft obtained this image of the giant asteroid Vesta with its framing camera on Aug. 14 2011. This image was taken through the camera clear filter. The image has a resolution of about 260 meters per pixel.

Low-cost printing of computerised tomography (CT) images where there is no dedicated CT camera.

PubMed

Tabari, Abdulkadir M

2007-01-01

Many developing countries still rely on conventional hard copy images to transfer information among physicians. We have developed a low-cost alternative method of printing computerised tomography (CT) scan images where there is no dedicated camera. A digital camera is used to photograph images from the CT scan screen monitor. The images are then transferred to a PC via a USB port, before being printed on glossy paper using an inkjet printer. The method can be applied to other imaging modalities like ultrasound and MRI and appears worthy of emulation elsewhere in the developing world where resources and technical expertise are scarce.

A small field of view camera for hybrid gamma and optical imaging

NASA Astrophysics Data System (ADS)

Lees, J. E.; Bugby, S. L.; Bhatia, B. S.; Jambi, L. K.; Alqahtani, M. S.; McKnight, W. R.; Ng, A. H.; Perkins, A. C.

2014-12-01

The development of compact low profile gamma-ray detectors has allowed the production of small field of view, hand held imaging devices for use at the patient bedside and in operating theatres. The combination of an optical and a gamma camera, in a co-aligned configuration, offers high spatial resolution multi-modal imaging giving a superimposed scintigraphic and optical image. This innovative introduction of hybrid imaging offers new possibilities for assisting surgeons in localising the site of uptake in procedures such as sentinel node detection. Recent improvements to the camera system along with results of phantom and clinical imaging are reported.

Sensor noise camera identification: countering counter-forensics

NASA Astrophysics Data System (ADS)

Goljan, Miroslav; Fridrich, Jessica; Chen, Mo

2010-01-01

In camera identification using sensor noise, the camera that took a given image can be determined with high certainty by establishing the presence of the camera's sensor fingerprint in the image. In this paper, we develop methods to reveal counter-forensic activities in which an attacker estimates the camera fingerprint from a set of images and pastes it onto an image from a different camera with the intent to introduce a false alarm and, in doing so, frame an innocent victim. We start by classifying different scenarios based on the sophistication of the attacker's activity and the means available to her and to the victim, who wishes to defend herself. The key observation is that at least some of the images that were used by the attacker to estimate the fake fingerprint will likely be available to the victim as well. We describe the socalled "triangle test" that helps the victim reveal attacker's malicious activity with high certainty under a wide range of conditions. This test is then extended to the case when none of the images that the attacker used to create the fake fingerprint are available to the victim but the victim has at least two forged images to analyze. We demonstrate the test's performance experimentally and investigate its limitations. The conclusion that can be made from this study is that planting a sensor fingerprint in an image without leaving a trace is significantly more difficult than previously thought.

Bundle Adjustment-Based Stability Analysis Method with a Case Study of a Dual Fluoroscopy Imaging System

NASA Astrophysics Data System (ADS)

Al-Durgham, K.; Lichti, D. D.; Detchev, I.; Kuntze, G.; Ronsky, J. L.

2018-05-01

A fundamental task in photogrammetry is the temporal stability analysis of a camera/imaging-system's calibration parameters. This is essential to validate the repeatability of the parameters' estimation, to detect any behavioural changes in the camera/imaging system and to ensure precise photogrammetric products. Many stability analysis methods exist in the photogrammetric literature; each one has different methodological bases, and advantages and disadvantages. This paper presents a simple and rigorous stability analysis method that can be straightforwardly implemented for a single camera or an imaging system with multiple cameras. The basic collinearity model is used to capture differences between two calibration datasets, and to establish the stability analysis methodology. Geometric simulation is used as a tool to derive image and object space scenarios. Experiments were performed on real calibration datasets from a dual fluoroscopy (DF; X-ray-based) imaging system. The calibration data consisted of hundreds of images and thousands of image observations from six temporal points over a two-day period for a precise evaluation of the DF system stability. The stability of the DF system - for a single camera analysis - was found to be within a range of 0.01 to 0.66 mm in terms of 3D coordinates root-mean-square-error (RMSE), and 0.07 to 0.19 mm for dual cameras analysis. It is to the authors' best knowledge that this work is the first to address the topic of DF stability analysis.

A survey of camera error sources in machine vision systems

NASA Astrophysics Data System (ADS)

Jatko, W. B.

In machine vision applications, such as an automated inspection line, television cameras are commonly used to record scene intensity in a computer memory or frame buffer. Scene data from the image sensor can then be analyzed with a wide variety of feature-detection techniques. Many algorithms found in textbooks on image processing make the implicit simplifying assumption of an ideal input image with clearly defined edges and uniform illumination. The ideal image model is helpful to aid the student in understanding the principles of operation, but when these algorithms are blindly applied to real-world images the results can be unsatisfactory. This paper examines some common measurement errors found in camera sensors and their underlying causes, and possible methods of error compensation. The role of the camera in a typical image-processing system is discussed, with emphasis on the origination of signal distortions. The effects of such things as lighting, optics, and sensor characteristics are considered.

Brandaris 128 ultra-high-speed imaging facility: 10 years of operation, updates, and enhanced features

NASA Astrophysics Data System (ADS)

Gelderblom, Erik C.; Vos, Hendrik J.; Mastik, Frits; Faez, Telli; Luan, Ying; Kokhuis, Tom J. A.; van der Steen, Antonius F. W.; Lohse, Detlef; de Jong, Nico; Versluis, Michel

2012-10-01

The Brandaris 128 ultra-high-speed imaging facility has been updated over the last 10 years through modifications made to the camera's hardware and software. At its introduction the camera was able to record 6 sequences of 128 images (500 × 292 pixels) at a maximum frame rate of 25 Mfps. The segmented mode of the camera was revised to allow for subdivision of the 128 image sensors into arbitrary segments (1-128) with an inter-segment time of 17 μs. Furthermore, a region of interest can be selected to increase the number of recordings within a single run of the camera from 6 up to 125. By extending the imaging system with a laser-induced fluorescence setup, time-resolved ultra-high-speed fluorescence imaging of microscopic objects has been enabled. Minor updates to the system are also reported here.

Flame Imaging System

NASA Technical Reports Server (NTRS)

Barnes, Heidi L. (Inventor); Smith, Harvey S. (Inventor)

1998-01-01

A system for imaging a flame and the background scene is discussed. The flame imaging system consists of two charge-coupled-device (CCD) cameras. One camera uses a 800 nm long pass filter which during overcast conditions blocks sufficient background light so the hydrogen flame is brighter than the background light, and the second CCD camera uses a 1100 nm long pass filter, which blocks the solar background in full sunshine conditions such that the hydrogen flame is brighter than the solar background. Two electronic viewfinders convert the signal from the cameras into a visible image. The operator can select the appropriate filtered camera to use depending on the current light conditions. In addition, a narrow band pass filtered InGaAs sensor at 1360 nm triggers an audible alarm and a flashing LED if the sensor detects a flame, providing additional flame detection so the operator does not overlook a small flame.

Measurement of Young’s modulus and Poisson’s ratio of metals by means of ESPI using a digital camera

NASA Astrophysics Data System (ADS)

Francisco, J. B. Pascual; Michtchenko, A.; Barragán Pérez, O.; Susarrey Huerta, O.

2016-09-01

In this paper, mechanical experiments with a low-cost interferometry set-up are presented. The set-up is suitable for an undergraduate laboratory where optical equipment is absent. The arrangement consists of two planes of illumination, allowing the measurement of the two perpendicular in-plane displacement directions. An axial load was applied on three different metals, and the longitudinal and transversal displacements were measured sequentially. A digital camera was used to acquire the images of the different states of load of the illuminated area. A personal computer was used to perform the digital subtraction of the images to obtain the fringe correlations, which are needed to calculate the displacements. Finally, Young’s modulus and Poisson’s ratio of the metals were calculated using the displacement data.

Development of a high-speed H-alpha camera system for the observation of rapid fluctuations in solar flares

NASA Technical Reports Server (NTRS)

Kiplinger, Alan L.; Dennis, Brian R.; Orwig, Larry E.; Chen, P. C.

1988-01-01

A solid-state digital camera was developed for obtaining H alpha images of solar flares with 0.1 s time resolution. Beginning in the summer of 1988, this system will be operated in conjunction with SMM's hard X-ray burst spectrometer (HXRBS). Important electron time-of-flight effects that are crucial for determining the flare energy release processes should be detectable with these combined H alpha and hard X-ray observations. Charge-injection device (CID) cameras provide 128 x 128 pixel images simultaneously in the H alpha blue wing, line center, and red wing, or other wavelength of interest. The data recording system employs a microprocessor-controlled, electronic interface between each camera and a digital processor board that encodes the data into a serial bitstream for continuous recording by a standard video cassette recorder. Only a small fraction of the data will be permanently archived through utilization of a direct memory access interface onto a VAX-750 computer. In addition to correlations with hard X-ray data, observations from the high speed H alpha camera will also be correlated and optical and microwave data and data from future MAX 1991 campaigns. Whether the recorded optical flashes are simultaneous with X-ray peaks to within 0.1 s, are delayed by tenths of seconds or are even undetectable, the results will have implications on the validity of both thermal and nonthermal models of hard X-ray production.

A Study of Deep CNN-Based Classification of Open and Closed Eyes Using a Visible Light Camera Sensor

PubMed Central

Kim, Ki Wan; Hong, Hyung Gil; Nam, Gi Pyo; Park, Kang Ryoung

2017-01-01

The necessity for the classification of open and closed eyes is increasing in various fields, including analysis of eye fatigue in 3D TVs, analysis of the psychological states of test subjects, and eye status tracking-based driver drowsiness detection. Previous studies have used various methods to distinguish between open and closed eyes, such as classifiers based on the features obtained from image binarization, edge operators, or texture analysis. However, when it comes to eye images with different lighting conditions and resolutions, it can be difficult to find an optimal threshold for image binarization or optimal filters for edge and texture extraction. In order to address this issue, we propose a method to classify open and closed eye images with different conditions, acquired by a visible light camera, using a deep residual convolutional neural network. After conducting performance analysis on both self-collected and open databases, we have determined that the classification accuracy of the proposed method is superior to that of existing methods. PMID:28665361

Object tracking with robotic total stations: Current technologies and improvements based on image data

NASA Astrophysics Data System (ADS)

Ehrhart, Matthias; Lienhart, Werner

2017-09-01

The importance of automated prism tracking is increasingly triggered by the rising automation of total station measurements in machine control, monitoring and one-person operation. In this article we summarize and explain the different techniques that are used to coarsely search a prism, to precisely aim at a prism, and to identify whether the correct prism is tracked. Along with the state-of-the-art review, we discuss and experimentally evaluate possible improvements based on the image data of an additional wide-angle camera which is available for many total stations today. In cases in which the total station's fine aiming module loses the prism, the tracked object may still be visible to the wide-angle camera because of its larger field of view. The theodolite angles towards the target can then be derived from its image coordinates which facilitates a fast reacquisition of the prism. In experimental measurements we demonstrate that our image-based approach for the coarse target search is 4 to 10-times faster than conventional approaches.

Single-camera stereo-digital image correlation with a four-mirror adapter: optimized design and validation

NASA Astrophysics Data System (ADS)

Yu, Liping; Pan, Bing

2016-12-01

A low-cost, easy-to-implement but practical single-camera stereo-digital image correlation (DIC) system using a four-mirror adapter is established for accurate shape and three-dimensional (3D) deformation measurements. The mirrors assisted pseudo-stereo imaging system can convert a single camera into two virtual cameras, which view a specimen from different angles and record the surface images of the test object onto two halves of the camera sensor. To enable deformation measurement in non-laboratory conditions or extreme high temperature environments, an active imaging optical design, combining an actively illuminated monochromatic source with a coupled band-pass optical filter, is compactly integrated to the pseudo-stereo DIC system. The optical design, basic principles and implementation procedures of the established system for 3D profile and deformation measurements are described in detail. The effectiveness and accuracy of the established system are verified by measuring the profile of a regular cylinder surface and displacements of a translated planar plate. As an application example, the established system is used to determine the tensile strains and Poisson's ratio of a composite solid propellant specimen during stress relaxation test. Since the established single-camera stereo-DIC system only needs a single camera and presents strong robustness against variations in ambient light or the thermal radiation of a hot object, it demonstrates great potential in determining transient deformation in non-laboratory or high-temperature environments with the aid of a single high-speed camera.

Development of Automated Tracking System with Active Cameras for Figure Skating

NASA Astrophysics Data System (ADS)

Haraguchi, Tomohiko; Taki, Tsuyoshi; Hasegawa, Junichi

This paper presents a system based on the control of PTZ cameras for automated real-time tracking of individual figure skaters moving on an ice rink. In the video images of figure skating, irregular trajectories, various postures, rapid movements, and various costume colors are included. Therefore, it is difficult to determine some features useful for image tracking. On the other hand, an ice rink has a limited area and uniform high intensity, and skating is always performed on ice. In the proposed system, an ice rink region is first extracted from a video image by the region growing method, and then, a skater region is extracted using the rink shape information. In the camera control process, each camera is automatically panned and/or tilted so that the skater region is as close to the center of the image as possible; further, the camera is zoomed to maintain the skater image at an appropriate scale. The results of experiments performed for 10 training scenes show that the skater extraction rate is approximately 98%. Thus, it was concluded that tracking with camera control was successful for almost all the cases considered in the study.

Achieving thermography with a thermal security camera using uncooled amorphous silicon microbolometer image sensors

NASA Astrophysics Data System (ADS)

Wang, Yu-Wei; Tesdahl, Curtis; Owens, Jim; Dorn, David

2012-06-01

Advancements in uncooled microbolometer technology over the last several years have opened up many commercial applications which had been previously cost prohibitive. Thermal technology is no longer limited to the military and government market segments. One type of thermal sensor with low NETD which is available in the commercial market segment is the uncooled amorphous silicon (α-Si) microbolometer image sensor. Typical thermal security cameras focus on providing the best image quality by auto tonemaping (contrast enhancing) the image, which provides the best contrast depending on the temperature range of the scene. While this may provide enough information to detect objects and activities, there are further benefits of being able to estimate the actual object temperatures in a scene. This thermographic ability can provide functionality beyond typical security cameras by being able to monitor processes. Example applications of thermography[2] with thermal camera include: monitoring electrical circuits, industrial machinery, building thermal leaks, oil/gas pipelines, power substations, etc...[3][5] This paper discusses the methodology of estimating object temperatures by characterizing/calibrating different components inside a thermal camera utilizing an uncooled amorphous silicon microbolometer image sensor. Plots of system performance across camera operating temperatures will be shown.

Calibration of Action Cameras for Photogrammetric Purposes

PubMed Central

Balletti, Caterina; Guerra, Francesco; Tsioukas, Vassilios; Vernier, Paolo

2014-01-01

The use of action cameras for photogrammetry purposes is not widespread due to the fact that until recently the images provided by the sensors, using either still or video capture mode, were not big enough to perform and provide the appropriate analysis with the necessary photogrammetric accuracy. However, several manufacturers have recently produced and released new lightweight devices which are: (a) easy to handle, (b) capable of performing under extreme conditions and more importantly (c) able to provide both still images and video sequences of high resolution. In order to be able to use the sensor of action cameras we must apply a careful and reliable self-calibration prior to the use of any photogrammetric procedure, a relatively difficult scenario because of the short focal length of the camera and its wide angle lens that is used to obtain the maximum possible resolution of images. Special software, using functions of the OpenCV library, has been created to perform both the calibration and the production of undistorted scenes for each one of the still and video image capturing mode of a novel action camera, the GoPro Hero 3 camera that can provide still images up to 12 Mp and video up 8 Mp resolution. PMID:25237898

Calibration of action cameras for photogrammetric purposes.

PubMed

Balletti, Caterina; Guerra, Francesco; Tsioukas, Vassilios; Vernier, Paolo

2014-09-18

The use of action cameras for photogrammetry purposes is not widespread due to the fact that until recently the images provided by the sensors, using either still or video capture mode, were not big enough to perform and provide the appropriate analysis with the necessary photogrammetric accuracy. However, several manufacturers have recently produced and released new lightweight devices which are: (a) easy to handle, (b) capable of performing under extreme conditions and more importantly (c) able to provide both still images and video sequences of high resolution. In order to be able to use the sensor of action cameras we must apply a careful and reliable self-calibration prior to the use of any photogrammetric procedure, a relatively difficult scenario because of the short focal length of the camera and its wide angle lens that is used to obtain the maximum possible resolution of images. Special software, using functions of the OpenCV library, has been created to perform both the calibration and the production of undistorted scenes for each one of the still and video image capturing mode of a novel action camera, the GoPro Hero 3 camera that can provide still images up to 12 Mp and video up 8 Mp resolution.

Electronic still camera

NASA Astrophysics Data System (ADS)

Holland, S. Douglas

1992-09-01

A handheld, programmable, digital camera is disclosed that supports a variety of sensors and has program control over the system components to provide versatility. The camera uses a high performance design which produces near film quality images from an electronic system. The optical system of the camera incorporates a conventional camera body that was slightly modified, thus permitting the use of conventional camera accessories, such as telephoto lenses, wide-angle lenses, auto-focusing circuitry, auto-exposure circuitry, flash units, and the like. An image sensor, such as a charge coupled device ('CCD') collects the photons that pass through the camera aperture when the shutter is opened, and produces an analog electrical signal indicative of the image. The analog image signal is read out of the CCD and is processed by preamplifier circuitry, a correlated double sampler, and a sample and hold circuit before it is converted to a digital signal. The analog-to-digital converter has an accuracy of eight bits to insure accuracy during the conversion. Two types of data ports are included for two different data transfer needs. One data port comprises a general purpose industrial standard port and the other a high speed/high performance application specific port. The system uses removable hard disks as its permanent storage media. The hard disk receives the digital image signal from the memory buffer and correlates the image signal with other sensed parameters, such as longitudinal or other information. When the storage capacity of the hard disk has been filled, the disk can be replaced with a new disk.

Can Commercial Digital Cameras Be Used as Multispectral Sensors? A Crop Monitoring Test

PubMed Central

Lebourgeois, Valentine; Bégué, Agnès; Labbé, Sylvain; Mallavan, Benjamin; Prévot, Laurent; Roux, Bruno

2008-01-01

The use of consumer digital cameras or webcams to characterize and monitor different features has become prevalent in various domains, especially in environmental applications. Despite some promising results, such digital camera systems generally suffer from signal aberrations due to the on-board image processing systems and thus offer limited quantitative data acquisition capability. The objective of this study was to test a series of radiometric corrections having the potential to reduce radiometric distortions linked to camera optics and environmental conditions, and to quantify the effects of these corrections on our ability to monitor crop variables. In 2007, we conducted a five-month experiment on sugarcane trial plots using original RGB and modified RGB (Red-Edge and NIR) cameras fitted onto a light aircraft. The camera settings were kept unchanged throughout the acquisition period and the images were recorded in JPEG and RAW formats. These images were corrected to eliminate the vignetting effect, and normalized between acquisition dates. Our results suggest that 1) the use of unprocessed image data did not improve the results of image analyses; 2) vignetting had a significant effect, especially for the modified camera, and 3) normalized vegetation indices calculated with vignetting-corrected images were sufficient to correct for scene illumination conditions. These results are discussed in the light of the experimental protocol and recommendations are made for the use of these versatile systems for quantitative remote sensing of terrestrial surfaces. PMID:27873930

Electronic Still Camera

NASA Technical Reports Server (NTRS)

Holland, S. Douglas (Inventor)

1992-01-01

A handheld, programmable, digital camera is disclosed that supports a variety of sensors and has program control over the system components to provide versatility. The camera uses a high performance design which produces near film quality images from an electronic system. The optical system of the camera incorporates a conventional camera body that was slightly modified, thus permitting the use of conventional camera accessories, such as telephoto lenses, wide-angle lenses, auto-focusing circuitry, auto-exposure circuitry, flash units, and the like. An image sensor, such as a charge coupled device ('CCD') collects the photons that pass through the camera aperture when the shutter is opened, and produces an analog electrical signal indicative of the image. The analog image signal is read out of the CCD and is processed by preamplifier circuitry, a correlated double sampler, and a sample and hold circuit before it is converted to a digital signal. The analog-to-digital converter has an accuracy of eight bits to insure accuracy during the conversion. Two types of data ports are included for two different data transfer needs. One data port comprises a general purpose industrial standard port and the other a high speed/high performance application specific port. The system uses removable hard disks as its permanent storage media. The hard disk receives the digital image signal from the memory buffer and correlates the image signal with other sensed parameters, such as longitudinal or other information. When the storage capacity of the hard disk has been filled, the disk can be replaced with a new disk.

Earth on the Horizon

NASA Image and Video Library

2004-03-13

This is the first image ever taken of Earth from the surface of a planet beyond the Moon. It was taken by the Mars Exploration Rover Spirit one hour before sunrise on the 63rd martian day, or sol, of its mission. Earth is the tiny white dot in the center. The image is a mosaic of images taken by the rover's navigation camera showing a broad view of the sky, and an image taken by the rover's panoramic camera of Earth. The contrast in the panoramic camera image was increased two times to make Earth easier to see. http://photojournal.jpl.nasa.gov/catalog/PIA05560

[Diagnostic use of positron emission tomography in France: from the coincidence gamma-camera to mobile hybrid PET/CT devices].

PubMed

Talbot, Jean-Noël

2010-11-01

Positron emission tomography (PET) is a well-established medical imaging method. PET is increasingly used for diagnostic purposes, especially in oncology. The most widely used radiopharmaceutical is FDG, a glucose analogue. Other radiopharmaceuticals have recently been registered or are in development. We outline technical improvements of PET machines during more than a decade of clinical use in France. Even though image quality has improved considerably and PET-CT hybrid machines have emerged, spending per examination has remained remarkably constant. Replacement and maintenance costs have remained in the range of 170-190 Euros per examination since 1997, whether early CDET gamma cameras or the latest time-of-flight PET/CT devices are used. This is mainly due to shorter acquisition times and more efficient use of FDG New reimbursement rates for PET/CT are needed in France in order to favor regular acquisition of state-of-the-art devices. One major development is the coupling of PET and MR imaging.

Image quality analysis of a color LCD as well as a monochrome LCD using a Foveon color CMOS camera

NASA Astrophysics Data System (ADS)

Dallas, William J.; Roehrig, Hans; Krupinski, Elizabeth A.

2007-09-01

We have combined a CMOS color camera with special software to compose a multi-functional image-quality analysis instrument. It functions as a colorimeter as well as measuring modulation transfer functions (MTF) and noise power spectra (NPS). It is presently being expanded to examine fixed-pattern noise and temporal noise. The CMOS camera has 9 μm square pixels and a pixel matrix of 2268 x 1512 x 3. The camera uses a sensor that has co-located pixels for all three primary colors. We have imaged sections of both a color and a monochrome LCD monitor onto the camera sensor with LCD-pixel-size to camera-pixel-size ratios of both 12:1 and 17.6:1. When used as an imaging colorimeter, each camera pixel is calibrated to provide CIE color coordinates and tristimulus values. This capability permits the camera to simultaneously determine chromaticity in different locations on the LCD display. After the color calibration with a CS-200 colorimeter the color coordinates of the display's primaries determined from the camera's luminance response are very close to those found from the CS-200. Only the color coordinates of the display's white point were in error. For calculating the MTF a vertical or horizontal line is displayed on the monitor. The captured image is color-matrix preprocessed, Fourier transformed then post-processed. For NPS, a uniform image is displayed on the monitor. Again, the image is pre-processed, transformed and processed. Our measurements show that the horizontal MTF's of both displays have a larger negative slope than that of the vertical MTF's. This behavior indicates that the horizontal MTF's are poorer than the vertical MTF's. However the modulations at the Nyquist frequency seem lower for the color LCD than for the monochrome LCD. The spatial noise of the color display in both directions is larger than that of the monochrome display. Attempts were also made to analyze the total noise in terms of spatial and temporal noise by applying subtractions of images taken at exactly the same exposure. Temporal noise seems to be significantly lower than spatial noise.

PubMed Central

Baum, S.; Sillem, M.; Ney, J. T.; Baum, A.; Friedrich, M.; Radosa, J.; Kramer, K. M.; Gronwald, B.; Gottschling, S.; Solomayer, E. F.; Rody, A.; Joukhadar, R.

2017-01-01

Introduction Minimally invasive operative techniques are being used increasingly in gynaecological surgery. The expansion of the laparoscopic operation spectrum is in part the result of improved imaging. This study investigates the practical advantages of using 3D cameras in routine surgical practice. Materials and Methods Two different 3-dimensional camera systems were compared with a 2-dimensional HD system; the operating surgeonʼs experiences were documented immediately postoperatively using a questionnaire. Results Significant advantages were reported for suturing and cutting of anatomical structures when using the 3D compared to 2D camera systems. There was only a slight advantage for coagulating. The use of 3D cameras significantly improved the general operative visibility and in particular the representation of spacial depth compared to 2-dimensional images. There was not a significant advantage for image width. Depiction of adhesions and retroperitoneal neural structures was significantly improved by the stereoscopic cameras, though this did not apply to blood vessels, ureter, uterus or ovaries. Conclusion 3-dimensional cameras were particularly advantageous for the depiction of fine anatomical structures due to improved spacial depth representation compared to 2D systems. 3D cameras provide the operating surgeon with a monitor image that more closely resembles actual anatomy, thus simplifying laparoscopic procedures. PMID:28190888

Line-Constrained Camera Location Estimation in Multi-Image Stereomatching.

PubMed

Donné, Simon; Goossens, Bart; Philips, Wilfried

2017-08-23

Stereomatching is an effective way of acquiring dense depth information from a scene when active measurements are not possible. So-called lightfield methods take a snapshot from many camera locations along a defined trajectory (usually uniformly linear or on a regular grid-we will assume a linear trajectory) and use this information to compute accurate depth estimates. However, they require the locations for each of the snapshots to be known: the disparity of an object between images is related to both the distance of the camera to the object and the distance between the camera positions for both images. Existing solutions use sparse feature matching for camera location estimation. In this paper, we propose a novel method that uses dense correspondences to do the same, leveraging an existing depth estimation framework to also yield the camera locations along the line. We illustrate the effectiveness of the proposed technique for camera location estimation both visually for the rectification of epipolar plane images and quantitatively with its effect on the resulting depth estimation. Our proposed approach yields a valid alternative for sparse techniques, while still being executed in a reasonable time on a graphics card due to its highly parallelizable nature.

Exploring the feasibility of iris recognition for visible spectrum iris images obtained using smartphone camera

NASA Astrophysics Data System (ADS)

Trokielewicz, Mateusz; Bartuzi, Ewelina; Michowska, Katarzyna; Andrzejewska, Antonina; Selegrat, Monika

2015-09-01

In the age of modern, hyperconnected society that increasingly relies on mobile devices and solutions, implementing a reliable and accurate biometric system employing iris recognition presents new challenges. Typical biometric systems employing iris analysis require expensive and complicated hardware. We therefore explore an alternative way using visible spectrum iris imaging. This paper aims at answering several questions related to applying iris biometrics for images obtained in the visible spectrum using smartphone camera. Can irides be successfully and effortlessly imaged using a smartphone's built-in camera? Can existing iris recognition methods perform well when presented with such images? The main advantage of using near-infrared (NIR) illumination in dedicated iris recognition cameras is good performance almost independent of the iris color and pigmentation. Are the images obtained from smartphone's camera of sufficient quality even for the dark irides? We present experiments incorporating simple image preprocessing to find the best visibility of iris texture, followed by a performance study to assess whether iris recognition methods originally aimed at NIR iris images perform well with visible light images. To our best knowledge this is the first comprehensive analysis of iris recognition performance using a database of high-quality images collected in visible light using the smartphones flashlight together with the application of commercial off-the-shelf (COTS) iris recognition methods.

Semi-automated camera trap image processing for the detection of ungulate fence crossing events.

PubMed

Janzen, Michael; Visser, Kaitlyn; Visscher, Darcy; MacLeod, Ian; Vujnovic, Dragomir; Vujnovic, Ksenija

2017-09-27

Remote cameras are an increasingly important tool for ecological research. While remote camera traps collect field data with minimal human attention, the images they collect require post-processing and characterization before it can be ecologically and statistically analyzed, requiring the input of substantial time and money from researchers. The need for post-processing is due, in part, to a high incidence of non-target images. We developed a stand-alone semi-automated computer program to aid in image processing, categorization, and data reduction by employing background subtraction and histogram rules. Unlike previous work that uses video as input, our program uses still camera trap images. The program was developed for an ungulate fence crossing project and tested against an image dataset which had been previously processed by a human operator. Our program placed images into categories representing the confidence of a particular sequence of images containing a fence crossing event. This resulted in a reduction of 54.8% of images that required further human operator characterization while retaining 72.6% of the known fence crossing events. This program can provide researchers using remote camera data the ability to reduce the time and cost required for image post-processing and characterization. Further, we discuss how this procedure might be generalized to situations not specifically related to animal use of linear features.

iPhone 4s and iPhone 5s Imaging of the Eye

PubMed Central

Jalil, Maaz; Ferenczy, Sandor R.; Shields, Carol L.

2017-01-01

Background/Aims To evaluate the technical feasibility of a consumer-grade cellular iPhone camera as an ocular imaging device compared to existing ophthalmic imaging equipment for documentation purposes. Methods A comparison of iPhone 4s and 5s images was made with external facial images (macrophotography) using Nikon cameras, slit-lamp images (microphotography) using Zeiss photo slit-lamp camera, and fundus images (fundus photography) using RetCam II. Results In an analysis of six consecutive patients with ophthalmic conditions, both iPhones achieved documentation of external findings (macrophotography) using standard camera modality, tap to focus, and built-in flash. Both iPhones achieved documentation of anterior segment findings (microphotography) during slit-lamp examination through oculars. Both iPhones achieved fundus imaging using standard video modality with continuous iPhone illumination through an ophthalmic lens. Comparison to standard ophthalmic cameras, macrophotography and microphotography were excellent. In comparison to RetCam fundus photography, iPhone fundus photography revealed smaller field and was technically more difficult to obtain, but the quality was nearly similar to RetCam. Conclusions iPhone versions 4s and 5s can provide excellent ophthalmic macrophotography and microphotography and adequate fundus photography. We believe that iPhone imaging could be most useful in settings where expensive, complicated, and cumbersome imaging equipment is unavailable. PMID:28275604

Portable, low-priced retinal imager for eye disease screening

NASA Astrophysics Data System (ADS)

Soliz, Peter; Nemeth, Sheila; VanNess, Richard; Barriga, E. S.; Zamora, Gilberto

2014-02-01

The objective of this project was to develop and demonstrate a portable, low-priced, easy to use non-mydriatic retinal camera for eye disease screening in underserved urban and rural locations. Existing portable retinal imagers do not meet the requirements of a low-cost camera with sufficient technical capabilities (field of view, image quality, portability, battery power, and ease-of-use) to be distributed widely to low volume clinics, such as the offices of single primary care physicians serving rural communities or other economically stressed healthcare facilities. Our approach for Smart i-Rx is based primarily on a significant departure from current generations of desktop and hand-held commercial retinal cameras as well as those under development. Our techniques include: 1) Exclusive use of off-the-shelf components; 2) Integration of retinal imaging device into low-cost, high utility camera mount and chin rest; 3) Unique optical and illumination designed for small form factor; and 4) Exploitation of autofocus technology built into present digital SLR recreational cameras; and 5) Integration of a polarization technique to avoid the corneal reflex. In a prospective study, 41 out of 44 diabetics were imaged successfully. No imaging was attempted on three of the subjects due to noticeably small pupils (less than 2mm). The images were of sufficient quality to detect abnormalities related to diabetic retinopathy, such as microaneurysms and exudates. These images were compared with ones taken non-mydriatically with a Canon CR-1 Mark II camera. No cases identified as having DR by expert retinal graders were missed in the Smart i-Rx images.

Measurement Capabilities of Single-Pulse Planar Doppler Velocimetry

NASA Technical Reports Server (NTRS)

McKenzie, Robert L.; Kutler, Paul F. (Technical Monitor)

1994-01-01

Preliminary investigations are described of a method that is capable of measuring instantaneous, 3-D, velocity vectors everywhere in a light sheet generated by a pulsed laser. The technique, here called Planar Doppler Velocimetry (PDV), is a variation of a new concept for velocity measurements that was called Doppler Global Velocimetry (DGV) in its original disclosure. The concept relies on the use of a narrowband laser and measurements of the Doppler shift of scattered light from particles moving with a flow. The Doppler shift is recorded as a variation in transmission through a sharp-edged spectral filter provided by iodine vapor in a cell. Entire fields of velocity can be determined by using a solid-state camera to record the intensity variations throughout the field of view. However, the implementation of DGV has been centered principally on the use of high power, continuous-wave, ion lasers and measurement times that are determined by the 30-ms framing times of standard video cameras. Hence, they provide velocity fields that are averaged in time at least over that period. On the other hand, the PDV concept described in this presentation incorporates a high energy, repetitively pulsed, Nd-YAG laser that is injection-seeded to make it narrowband and then frequency-doubled to provide light at frequencies absorbed by the iodine vapor. The duration of each pulse is less than 10 nanoseconds. When used in combination with nonstandard, scientific quality, solid state cameras, a sequence of images can be obtained that provides instantaneous velocity vectors everywhere in the field of view. The investigations described in this paper include an accurate characterization of the iodine cell spectral behavior and its influence on the PDV measurements, a derivation of the PDV signal analysis requirements, and the unique aspects of the pulsed laser behavior related to this application. In addition, PDV measurements are to be demonstrated using data from a rotating wheel target and from the flow of a subsonic jet. Initially, single optical fiber light collection and photomultiplier detectors will be substituted for solid state cameras. Those results will allow the determination of the fundamental limitations of the PDV technique without the complications of image acquisition and processing. They will then be used to provide an analysis of the measurement capabilities of PDV both in small aerodynamic research wind tunnels and in large wind tunnels designed for production airframe and propulsion testing. Future plans include the implementation of solid state cameras and the development of the required image acquisition and processing software. Eventually, the PDV technique will be applied to an aerodynamic research program related to transonic wing flutter.

Optical Transient Monitor (OTM) for BOOTES Project

NASA Astrophysics Data System (ADS)

Páta, P.; Bernas, M.; Castro-Tirado, A. J.; Hudec, R.

2003-04-01

The Optical Transient Monitor (OTM) is a software for control of three wide and ultra-wide filed cameras of BOOTES (Burst Observer and Optical Transient Exploring System) station. The OTM is a PC based and it is powerful tool for taking images from two SBIG CCD cameras in same time or from one camera only. The control program for BOOTES cameras is Windows 98 or MSDOS based. Now the version for Windows 2000 is prepared. There are five main supported modes of work. The OTM program could control cameras and evaluate image data without human interaction.

Noise and sensitivity of x-ray framing cameras at Nike (abstract)

NASA Astrophysics Data System (ADS)

Pawley, C. J.; Deniz, A. V.; Lehecka, T.

1999-01-01

X-ray framing cameras are the most widely used tool for radiographing density distributions in laser and Z-pinch driven experiments. The x-ray framing cameras that were developed specifically for experiments on the Nike laser system are described. One of these cameras has been coupled to a CCD camera and was tested for resolution and image noise using both electrons and x rays. The largest source of noise in the images was found to be due to low quantum detection efficiency of x-ray photons.

Recognizable-image selection for fingerprint recognition with a mobile-device camera.

PubMed

Lee, Dongjae; Choi, Kyoungtaek; Choi, Heeseung; Kim, Jaihie

2008-02-01

This paper proposes a recognizable-image selection algorithm for fingerprint-verification systems that use a camera embedded in a mobile device. A recognizable image is defined as the fingerprint image which includes the characteristics that are sufficiently discriminating an individual from other people. While general camera systems obtain focused images by using various gradient measures to estimate high-frequency components, mobile cameras cannot acquire recognizable images in the same way because the obtained images may not be adequate for fingerprint recognition, even if they are properly focused. A recognizable image has to meet the following two conditions: First, valid region in the recognizable image should be large enough compared with other nonrecognizable images. Here, a valid region is a well-focused part, and ridges in the region are clearly distinguishable from valleys. In order to select valid regions, this paper proposes a new focus-measurement algorithm using the secondary partial derivatives and a quality estimation utilizing the coherence and symmetry of gradient distribution. Second, rolling and pitching degrees of a finger measured from the camera plane should be within some limit for a recognizable image. The position of a core point and the contour of a finger are used to estimate the degrees of rolling and pitching. Experimental results show that our proposed method selects valid regions and estimates the degrees of rolling and pitching properly. In addition, fingerprint-verification performance is improved by detecting the recognizable images.

NPS assessment of color medical displays using a monochromatic CCD camera

NASA Astrophysics Data System (ADS)

Roehrig, Hans; Gu, Xiliang; Fan, Jiahua

2012-02-01

This paper presents an approach to Noise Power Spectrum (NPS) assessment of color medical displays without using an expensive imaging colorimeter. The R, G and B color uniform patterns were shown on the display under study and the images were taken using a high resolution monochromatic camera. A colorimeter was used to calibrate the camera images. Synthetic intensity images were formed by the weighted sum of the R, G, B and the dark screen images. Finally the NPS analysis was conducted on the synthetic images. The proposed method replaces an expensive imaging colorimeter for NPS evaluation, which also suggests a potential solution for routine color medical display QA/QC in the clinical area, especially when imaging of display devices is desired.

Privacy Protection by Masking Moving Objects for Security Cameras

NASA Astrophysics Data System (ADS)

Yabuta, Kenichi; Kitazawa, Hitoshi; Tanaka, Toshihisa

Because of an increasing number of security cameras, it is crucial to establish a system that protects the privacy of objects in the recorded images. To this end, we propose a framework of image processing and data hiding for security monitoring and privacy protection. First, we state the requirements of the proposed monitoring systems and suggest possible implementation that satisfies those requirements. The underlying concept of our proposed framework is as follows: (1) in the recorded images, the objects whose privacy should be protected are deteriorated by appropriate image processing; (2) the original objects are encrypted and watermarked into the output image, which is encoded using an image compression standard; (3) real-time processing is performed such that no future frame is required to generate on output bitstream. It should be noted that in this framework, anyone can observe the decoded image that includes the deteriorated objects that are unrecognizable or invisible. On the other hand, for crime investigation, this system allows a limited number of users to observe the original objects by using a special viewer that decrypts and decodes the watermarked objects with a decoding password. Moreover, the special viewer allows us to select the objects to be decoded and displayed. We provide an implementation example, experimental results, and performance evaluations to support our proposed framework.

Concept of a photon-counting camera based on a diffraction-addressed Gray-code mask

NASA Astrophysics Data System (ADS)

Morel, Sébastien

2004-09-01

A new concept of photon counting camera for fast and low-light-level imaging applications is introduced. The possible spectrum covered by this camera ranges from visible light to gamma rays, depending on the device used to transform an incoming photon into a burst of visible photons (photo-event spot) localized in an (x,y) image plane. It is actually an evolution of the existing "PAPA" (Precision Analog Photon Address) Camera that was designed for visible photons. This improvement comes from a simplified optics. The new camera transforms, by diffraction, each photo-event spot from an image intensifier or a scintillator into a cross-shaped pattern, which is projected onto a specific Gray code mask. The photo-event position is then extracted from the signal given by an array of avalanche photodiodes (or photomultiplier tubes, alternatively) downstream of the mask. After a detailed explanation of this camera concept that we have called "DIAMICON" (DIffraction Addressed Mask ICONographer), we briefly discuss about technical solutions to build such a camera.

High-speed imaging using 3CCD camera and multi-color LED flashes

NASA Astrophysics Data System (ADS)

Hijazi, Ala; Friedl, Alexander; Cierpka, Christian; Kähler, Christian; Madhavan, Vis

2017-11-01

This paper demonstrates the possibility of capturing full-resolution, high-speed image sequences using a regular 3CCD color camera in conjunction with high-power light emitting diodes of three different colors. This is achieved using a novel approach, referred to as spectral-shuttering, where a high-speed image sequence is captured using short duration light pulses of different colors that are sent consecutively in very close succession. The work presented in this paper demonstrates the feasibility of configuring a high-speed camera system using low cost and readily available off-the-shelf components. This camera can be used for recording six-frame sequences at frame rates up to 20 kHz or three-frame sequences at even higher frame rates. Both color crosstalk and spatial matching between the different channels of the camera are found to be within acceptable limits. A small amount of magnification difference between the different channels is found and a simple calibration procedure for correcting the images is introduced. The images captured using the approach described here are of good quality to be used for obtaining full-field quantitative information using techniques such as digital image correlation and particle image velocimetry. A sequence of six high-speed images of a bubble splash recorded at 400 Hz is presented as a demonstration.

A position and attitude vision measurement system for wind tunnel slender model

NASA Astrophysics Data System (ADS)

Cheng, Lei; Yang, Yinong; Xue, Bindang; Zhou, Fugen; Bai, Xiangzhi

2014-11-01

A position and attitude vision measurement system for drop test slender model in wind tunnel is designed and developed. The system used two high speed cameras, one is put to the side of the model and another is put to the position where the camera can look up the model. Simple symbols are set on the model. The main idea of the system is based on image matching technique between the 3D-digital model projection image and the image captured by the camera. At first, we evaluate the pitch angles, the roll angles and the position of the centroid of a model through recognizing symbols in the images captured by the side camera. And then, based on the evaluated attitude info, giving a series of yaw angles, a series of projection images of the 3D-digital model are obtained. Finally, these projection images are matched with the image which captured by the looking up camera, and the best match's projection images corresponds to the yaw angle is the very yaw angle of the model. Simulation experiments are conducted and the results show that the maximal error of attitude measurement is less than 0.05°, which can meet the demand of test in wind tunnel.

Applying image quality in cell phone cameras: lens distortion

NASA Astrophysics Data System (ADS)

Baxter, Donald; Goma, Sergio R.; Aleksic, Milivoje

2009-01-01

This paper describes the framework used in one of the pilot studies run under the I3A CPIQ initiative to quantify overall image quality in cell-phone cameras. The framework is based on a multivariate formalism which tries to predict overall image quality from individual image quality attributes and was validated in a CPIQ pilot program. The pilot study focuses on image quality distortions introduced in the optical path of a cell-phone camera, which may or may not be corrected in the image processing path. The assumption is that the captured image used is JPEG compressed and the cellphone camera is set to 'auto' mode. As the used framework requires that the individual attributes to be relatively perceptually orthogonal, in the pilot study, the attributes used are lens geometric distortion (LGD) and lateral chromatic aberrations (LCA). The goal of this paper is to present the framework of this pilot project starting with the definition of the individual attributes, up to their quantification in JNDs of quality, a requirement of the multivariate formalism, therefore both objective and subjective evaluations were used. A major distinction in the objective part from the 'DSC imaging world' is that the LCA/LGD distortions found in cell-phone cameras, rarely exhibit radial behavior, therefore a radial mapping/modeling cannot be used in this case.

Embedded processor extensions for image processing

NASA Astrophysics Data System (ADS)

Thevenin, Mathieu; Paindavoine, Michel; Letellier, Laurent; Heyrman, Barthélémy

2008-04-01

The advent of camera phones marks a new phase in embedded camera sales. By late 2009, the total number of camera phones will exceed that of both conventional and digital cameras shipped since the invention of photography. Use in mobile phones of applications like visiophony, matrix code readers and biometrics requires a high degree of component flexibility that image processors (IPs) have not, to date, been able to provide. For all these reasons, programmable processor solutions have become essential. This paper presents several techniques geared to speeding up image processors. It demonstrates that a gain of twice is possible for the complete image acquisition chain and the enhancement pipeline downstream of the video sensor. Such results confirm the potential of these computing systems for supporting future applications.

Automated optical testing of LWIR objective lenses using focal plane array sensors

NASA Astrophysics Data System (ADS)

Winters, Daniel; Erichsen, Patrik; Domagalski, Christian; Peter, Frank; Heinisch, Josef; Dumitrescu, Eugen

2012-10-01

The image quality of today's state-of-the-art IR objective lenses is constantly improving while at the same time the market for thermography and vision grows strongly. Because of increasing demands on the quality of IR optics and increasing production volumes, the standards for image quality testing increase and tests need to be performed in shorter time. Most high-precision MTF testing equipment for the IR spectral bands in use today relies on the scanning slit method that scans a 1D detector over a pattern in the image generated by the lens under test, followed by image analysis to extract performance parameters. The disadvantages of this approach are that it is relatively slow, it requires highly trained operators for aligning the sample and the number of parameters that can be extracted is limited. In this paper we present lessons learned from the R and D process on using focal plane array (FPA) sensors for testing of long-wave IR (LWIR, 8-12 m) optics. Factors that need to be taken into account when switching from scanning slit to FPAs are e.g.: the thermal background from the environment, the low scene contrast in the LWIR, the need for advanced image processing algorithms to pre-process camera images for analysis and camera artifacts. Finally, we discuss 2 measurement systems for LWIR lens characterization that we recently developed with different target applications: 1) A fully automated system suitable for production testing and metrology that uses uncooled microbolometer cameras to automatically measure MTF (on-axis and at several o-axis positions) and parameters like EFL, FFL, autofocus curves, image plane tilt, etc. for LWIR objectives with an EFL between 1 and 12mm. The measurement cycle time for one sample is typically between 6 and 8s. 2) A high-precision research-grade system using again an uncooled LWIR camera as detector, that is very simple to align and operate. A wide range of lens parameters (MTF, EFL, astigmatism, distortion, etc.) can be easily and accurately measured with this system.

MO-AB-206-00: Nuclear Medicine Physics and Testing

DOE Office of Scientific and Technical Information (OSTI.GOV)

NONE

This education session will cover the physics and operation principles of gamma cameras and PET scanners. The first talk will focus on PET imaging. An overview of the principles of PET imaging will be provided, including positron decay physics, and the transition from 2D to 3D imaging. More recent advances in hardware and software will be discussed, such as time-of-flight imaging, and improvements in reconstruction algorithms that provide for options such as depth-of-interaction corrections. Quantitative applications of PET will be discussed, as well as the requirements for doing accurate quantitation. Relevant performance tests will also be described. Learning Objectives: Bemore » able to describe basic physics principles of PET and operation of PET scanners. Learn about recent advances in PET scanner hardware technology. Be able to describe advances in reconstruction techniques and improvements Be able to list relevant performance tests. The second talk will focus on gamma cameras. The Nuclear Medicine subcommittee has charged a task group (TG177) to develop a report on the current state of physics testing of gamma cameras, SPECT, and SPECT/CT systems. The report makes recommendations for performance tests to be done for routine quality assurance, annual physics testing, and acceptance tests, and identifies those needed satisfy the ACR accreditation program and The Joint Commission imaging standards. The report is also intended to be used as a manual with detailed instructions on how to perform tests under widely varying conditions. Learning Objectives: At the end of the presentation members of the audience will: Be familiar with the tests recommended for routine quality assurance, annual physics testing, and acceptance tests of gamma cameras for planar imaging. Be familiar with the tests recommended for routine quality assurance, annual physics testing, and acceptance tests of SPECT systems. Be familiar with the tests of a SPECT/CT system that include the CT images for SPECT reconstructions. Become knowledgeable of items to be included in annual acceptance testing reports including CT dosimetry and PACS monitor measurements. T. Turkington, GE Healthcare.« less

A new compact, high sensitivity neutron imaging systema)

NASA Astrophysics Data System (ADS)

Caillaud, T.; Landoas, O.; Briat, M.; Rossé, B.; Thfoin, I.; Philippe, F.; Casner, A.; Bourgade, J. L.; Disdier, L.; Glebov, V. Yu.; Marshall, F. J.; Sangster, T. C.; Park, H. S.; Robey, H. F.; Amendt, P.

2012-10-01

We have developed a new small neutron imaging system (SNIS) diagnostic for the OMEGA laser facility. The SNIS uses a penumbral coded aperture and has been designed to record images from low yield (109-1010 neutrons) implosions such as those using deuterium as the fuel. This camera was tested at OMEGA in 2009 on a rugby hohlraum energetics experiment where it recorded an image at a yield of 1.4 × 1010. The resolution of this image was 54 μm and the camera was located only 4 meters from target chamber centre. We recently improved the instrument by adding a cooled CCD camera. The sensitivity of the new camera has been fully characterized using a linear accelerator and a 60Co γ-ray source. The calibration showed that the signal-to-noise ratio could be improved by using raw binning detection.

Enhancement of low light level images using color-plus-mono dual camera.

PubMed

Jung, Yong Ju

2017-05-15

In digital photography, the improvement of imaging quality in low light shooting is one of the users' needs. Unfortunately, conventional smartphone cameras that use a single, small image sensor cannot provide satisfactory quality in low light level images. A color-plus-mono dual camera that consists of two horizontally separate image sensors, which simultaneously captures both a color and mono image pair of the same scene, could be useful for improving the quality of low light level images. However, an incorrect image fusion between the color and mono image pair could also have negative effects, such as the introduction of severe visual artifacts in the fused images. This paper proposes a selective image fusion technique that applies an adaptive guided filter-based denoising and selective detail transfer to only those pixels deemed reliable with respect to binocular image fusion. We employ a dissimilarity measure and binocular just-noticeable-difference (BJND) analysis to identify unreliable pixels that are likely to cause visual artifacts during image fusion via joint color image denoising and detail transfer from the mono image. By constructing an experimental system of color-plus-mono camera, we demonstrate that the BJND-aware denoising and selective detail transfer is helpful in improving the image quality during low light shooting.

Novel Robotic Tools for Piping Inspection and Repair, Phase 1

DTIC Science & Technology

2014-02-13

35 Figure 57 - Accowle ODVS cross section and reflective path ......................................... 36 Figure 58 - Leopard Imaging HD...mounted to iPhone ............................................................................. 39 Figure 63 - Kogeto mounted to Leopard Imaging HD...40 Figure 65 - Leopard Imaging HD camera pipe test (letters) ............................................. 40 Figure 66 - Leopard Imaging HD camera

A multipurpose camera system for monitoring Kīlauea Volcano, Hawai'i

USGS Publications Warehouse

Patrick, Matthew R.; Orr, Tim R.; Lee, Lopaka; Moniz, Cyril J.

2015-01-01

We describe a low-cost, compact multipurpose camera system designed for field deployment at active volcanoes that can be used either as a webcam (transmitting images back to an observatory in real-time) or as a time-lapse camera system (storing images onto the camera system for periodic retrieval during field visits). The system also has the capability to acquire high-definition video. The camera system uses a Raspberry Pi single-board computer and a 5-megapixel low-light (near-infrared sensitive) camera, as well as a small Global Positioning System (GPS) module to ensure accurate time-stamping of images. Custom Python scripts control the webcam and GPS unit and handle data management. The inexpensive nature of the system allows it to be installed at hazardous sites where it might be lost. Another major advantage of this camera system is that it provides accurate internal timing (independent of network connection) and, because a full Linux operating system and the Python programming language are available on the camera system itself, it has the versatility to be configured for the specific needs of the user. We describe example deployments of the camera at Kīlauea Volcano, Hawai‘i, to monitor ongoing summit lava lake activity. 

Two-Camera Acquisition and Tracking of a Flying Target

NASA Technical Reports Server (NTRS)

Biswas, Abhijit; Assad, Christopher; Kovalik, Joseph M.; Pain, Bedabrata; Wrigley, Chris J.; Twiss, Peter

2008-01-01

A method and apparatus have been developed to solve the problem of automated acquisition and tracking, from a location on the ground, of a luminous moving target in the sky. The method involves the use of two electronic cameras: (1) a stationary camera having a wide field of view, positioned and oriented to image the entire sky; and (2) a camera that has a much narrower field of view (a few degrees wide) and is mounted on a two-axis gimbal. The wide-field-of-view stationary camera is used to initially identify the target against the background sky. So that the approximate position of the target can be determined, pixel locations on the image-detector plane in the stationary camera are calibrated with respect to azimuth and elevation. The approximate target position is used to initially aim the gimballed narrow-field-of-view camera in the approximate direction of the target. Next, the narrow-field-of view camera locks onto the target image, and thereafter the gimbals are actuated as needed to maintain lock and thereby track the target with precision greater than that attainable by use of the stationary camera.

High speed photography, videography, and photonics III; Proceedings of the Meeting, San Diego, CA, August 22, 23, 1985

NASA Technical Reports Server (NTRS)

Ponseggi, B. G. (Editor); Johnson, H. C. (Editor)

1985-01-01

Papers are presented on the picosecond electronic framing camera, photogrammetric techniques using high-speed cineradiography, picosecond semiconductor lasers for characterizing high-speed image shutters, the measurement of dynamic strain by high-speed moire photography, the fast framing camera with independent frame adjustments, design considerations for a data recording system, and nanosecond optical shutters. Consideration is given to boundary-layer transition detectors, holographic imaging, laser holographic interferometry in wind tunnels, heterodyne holographic interferometry, a multispectral video imaging and analysis system, a gated intensified camera, a charge-injection-device profile camera, a gated silicon-intensified-target streak tube and nanosecond-gated photoemissive shutter tubes. Topics discussed include high time-space resolved photography of lasers, time-resolved X-ray spectrographic instrumentation for laser studies, a time-resolving X-ray spectrometer, a femtosecond streak camera, streak tubes and cameras, and a short pulse X-ray diagnostic development facility.

Design and realization of an AEC&AGC system for the CCD aerial camera

NASA Astrophysics Data System (ADS)

Liu, Hai ying; Feng, Bing; Wang, Peng; Li, Yan; Wei, Hao yun

2015-08-01

An AEC and AGC(Automatic Exposure Control and Automatic Gain Control) system was designed for a CCD aerial camera with fixed aperture and electronic shutter. The normal AEC and AGE algorithm is not suitable to the aerial camera since the camera always takes high-resolution photographs in high-speed moving. The AEC and AGE system adjusts electronic shutter and camera gain automatically according to the target brightness and the moving speed of the aircraft. An automatic Gamma correction is used before the image is output so that the image is better for watching and analyzing by human eyes. The AEC and AGC system could avoid underexposure, overexposure, or image blurring caused by fast moving or environment vibration. A series of tests proved that the system meet the requirements of the camera system with its fast adjusting speed, high adaptability, high reliability in severe complex environment.

NGEE Arctic Zero Power Warming PhenoCamera Images, Barrow, Alaska, 2016

DOE Data Explorer

Shawn Serbin; Andrew McMahon; Keith Lewin; Kim Ely; Alistair Rogers

2016-11-14

StarDot NetCam SC pheno camera images collected from the top of the Barrow, BEO Sled Shed. The camera was installed to monitor the BNL TEST group's prototype ZPW (Zero Power Warming) chambers during the growing season of 2016 (including early spring and late fall). Images were uploaded to the BNL FTP server every 10 minutes and renamed with the date and time of the image. See associated data "Zero Power Warming (ZPW) Chamber Prototype Measurements, Barrow, Alaska, 2016" http://dx.doi.org/10.5440/1343066.

Low-cost laser speckle contrast imaging of blood flow using a webcam.

PubMed

Richards, Lisa M; Kazmi, S M Shams; Davis, Janel L; Olin, Katherine E; Dunn, Andrew K

2013-01-01

Laser speckle contrast imaging has become a widely used tool for dynamic imaging of blood flow, both in animal models and in the clinic. Typically, laser speckle contrast imaging is performed using scientific-grade instrumentation. However, due to recent advances in camera technology, these expensive components may not be necessary to produce accurate images. In this paper, we demonstrate that a consumer-grade webcam can be used to visualize changes in flow, both in a microfluidic flow phantom and in vivo in a mouse model. A two-camera setup was used to simultaneously image with a high performance monochrome CCD camera and the webcam for direct comparison. The webcam was also tested with inexpensive aspheric lenses and a laser pointer for a complete low-cost, compact setup ($90, 5.6 cm length, 25 g). The CCD and webcam showed excellent agreement with the two-camera setup, and the inexpensive setup was used to image dynamic blood flow changes before and after a targeted cerebral occlusion.

Low-cost laser speckle contrast imaging of blood flow using a webcam

PubMed Central

Richards, Lisa M.; Kazmi, S. M. Shams; Davis, Janel L.; Olin, Katherine E.; Dunn, Andrew K.

2013-01-01

Laser speckle contrast imaging has become a widely used tool for dynamic imaging of blood flow, both in animal models and in the clinic. Typically, laser speckle contrast imaging is performed using scientific-grade instrumentation. However, due to recent advances in camera technology, these expensive components may not be necessary to produce accurate images. In this paper, we demonstrate that a consumer-grade webcam can be used to visualize changes in flow, both in a microfluidic flow phantom and in vivo in a mouse model. A two-camera setup was used to simultaneously image with a high performance monochrome CCD camera and the webcam for direct comparison. The webcam was also tested with inexpensive aspheric lenses and a laser pointer for a complete low-cost, compact setup ($90, 5.6 cm length, 25 g). The CCD and webcam showed excellent agreement with the two-camera setup, and the inexpensive setup was used to image dynamic blood flow changes before and after a targeted cerebral occlusion. PMID:24156082

HIGH SPEED KERR CELL FRAMING CAMERA

DOEpatents

Goss, W.C.; Gilley, L.F.

1964-01-01

The present invention relates to a high speed camera utilizing a Kerr cell shutter and a novel optical delay system having no moving parts. The camera can selectively photograph at least 6 frames within 9 x 10/sup -8/ seconds during any such time interval of an occurring event. The invention utilizes particularly an optical system which views and transmits 6 images of an event to a multi-channeled optical delay relay system. The delay relay system has optical paths of successively increased length in whole multiples of the first channel optical path length, into which optical paths the 6 images are transmitted. The successively delayed images are accepted from the exit of the delay relay system by an optical image focusing means, which in turn directs the images into a Kerr cell shutter disposed to intercept the image paths. A camera is disposed to simultaneously view and record the 6 images during a single exposure of the Kerr cell shutter. (AEC)

Design of a high-numerical-aperture digital micromirror device camera with high dynamic range.

PubMed

Qiao, Yang; Xu, Xiping; Liu, Tao; Pan, Yue

2015-01-01

A high-NA imaging system with high dynamic range is presented based on a digital micromirror device (DMD). The DMD camera consists of an objective imaging system and a relay imaging system, connected by a DMD chip. With the introduction of a total internal reflection prism system, the objective imaging system is designed with a working F/# of 1.97, breaking through the F/2.45 limitation of conventional DMD projection lenses. As for the relay imaging system, an off-axis design that could correct off-axis aberrations of the tilt relay imaging system is developed. This structure has the advantage of increasing the NA of the imaging system while maintaining a compact size. Investigation revealed that the dynamic range of a DMD camera could be greatly increased, by 2.41 times. We built one prototype DMD camera with a working F/# of 1.23, and the field experiments proved the validity and reliability our work.

Performance benefits and limitations of a camera network

NASA Astrophysics Data System (ADS)

Carr, Peter; Thomas, Paul J.; Hornsey, Richard

2005-06-01

Visual information is of vital significance to both animals and artificial systems. The majority of mammals rely on two images, each with a resolution of 107-108 'pixels' per image. At the other extreme are insect eyes where the field of view is segmented into 103-105 images, each comprising effectively one pixel/image. The great majority of artificial imaging systems lie nearer to the mammalian characteristics in this parameter space, although electronic compound eyes have been developed in this laboratory and elsewhere. If the definition of a vision system is expanded to include networks or swarms of sensor elements, then schools of fish, flocks of birds and ant or termite colonies occupy a region where the number of images and the pixels/image may be comparable. A useful system might then have 105 imagers, each with about 104-105 pixels. Artificial analogs to these situations include sensor webs, smart dust and co-ordinated robot clusters. As an extreme example, we might consider the collective vision system represented by the imminent existence of ~109 cellular telephones, each with a one-megapixel camera. Unoccupied regions in this resolution-segmentation parameter space suggest opportunities for innovative artificial sensor network systems. Essential for the full exploitation of these opportunities is the availability of custom CMOS image sensor chips whose characteristics can be tailored to the application. Key attributes of such a chip set might include integrated image processing and control, low cost, and low power. This paper compares selected experimentally determined system specifications for an inward-looking array of 12 cameras with the aid of a camera-network model developed to explore the tradeoff between camera resolution and the number of cameras.

Developments in mercuric iodide gamma ray imaging

DOE Office of Scientific and Technical Information (OSTI.GOV)

Patt, B.E.; Beyerle, A.G.; Dolin, R.C.

A mercuric iodide gamma-ray imaging array and camera system previously described has been characterized for spatial and energy resolution. Based on this data a new camera is being developed to more fully exploit the potential of the array. Characterization results and design criterion for the new camera will be presented. 2 refs., 7 figs.

Seeing the Light: A Classroom-Sized Pinhole Camera Demonstration for Teaching Vision

ERIC Educational Resources Information Center

Prull, Matthew W.; Banks, William P.

2005-01-01

We describe a classroom-sized pinhole camera demonstration (camera obscura) designed to enhance students' learning of the visual system. The demonstration consists of a suspended rear-projection screen onto which the outside environment projects images through a small hole in a classroom window. Students can observe these images in a darkened…

An airborne multispectral imaging system based on two consumer-grade cameras for agricultural remote sensing

USDA-ARS?s Scientific Manuscript database

This paper describes the design and evaluation of an airborne multispectral imaging system based on two identical consumer-grade cameras for agricultural remote sensing. The cameras are equipped with a full-frame complementary metal oxide semiconductor (CMOS) sensor with 5616 × 3744 pixels. One came...

Injector Mixing Efficiency Experiments

NASA Technical Reports Server (NTRS)

Moser, Marlow D.

1998-01-01

Various optical diagnostic techniques such as laser induce fluorescence, Raman spectroscopy, laser Doppler velocimetry, and laser light scattering have been employed to study the flowfield downstream of a single injector element in a optically accessible rocket chamber at Penn State for a number o years. These techniques have been used with both liquid and gaseous oxygen at pressures up to 1000 psia which is the limit of the facility. The purpose of the test programs at Penn State were to develop the techniques and to study the flow field from various injector designs. To extend these studies to higher pressure and ultimately to multiple injectors require the capabilities of the Marshall Space Flight Center. These studies will extend the data base available for the various injector designs to higher pressure as well as to determine the interaction between multiple injectors. During this effort the Princeton Instruments ICCD camera was set up and checked out. The functionality of the system has been thoroughly checked and the shutter compensation time was found to be not working. The controller was returned to the manufacturer for warranty repair. The sensitivity has been measured and found to be approximately 60 counts per photon at maximum gain which agrees with the test data supplied by the manufacturer. The actual value depends on wavelength. The Princeton Instruments camera was been installed in a explosion proof tube for use with the rocket combustor. A 35 mm camera was also made ready for taking still photos inside the combustor. A fiber optic was used to transmit the laser light from an argon-ion laser to the rocket combustor for the light scattering images. This images were obtained for a LOX-hydrogen swirl coax injector. Several still photos were also obtained with the 35 mm camera for these firings.

Completely optical orientation determination for an unstabilized aerial three-line camera

NASA Astrophysics Data System (ADS)

Wohlfeil, Jürgen

2010-10-01

Aerial line cameras allow the fast acquisition of high-resolution images at low costs. Unfortunately the measurement of the camera's orientation with the necessary rate and precision is related with large effort, unless extensive camera stabilization is used. But also stabilization implicates high costs, weight, and power consumption. This contribution shows that it is possible to completely derive the absolute exterior orientation of an unstabilized line camera from its images and global position measurements. The presented approach is based on previous work on the determination of the relative orientation of subsequent lines using optical information from the remote sensing system. The relative orientation is used to pre-correct the line images, in which homologous points can reliably be determined using the SURF operator. Together with the position measurements these points are used to determine the absolute orientation from the relative orientations via bundle adjustment of a block of overlapping line images. The approach was tested at a flight with the DLR's RGB three-line camera MFC. To evaluate the precision of the resulting orientation the measurements of a high-end navigation system and ground control points are used.

Device for wavelength-selective imaging

DOEpatents

Frangioni, John V.

2010-09-14

An imaging device captures both a visible light image and a diagnostic image, the diagnostic image corresponding to emissions from an imaging medium within the object. The visible light image (which may be color or grayscale) and the diagnostic image may be superimposed to display regions of diagnostic significance within a visible light image. A number of imaging media may be used according to an intended application for the imaging device, and an imaging medium may have wavelengths above, below, or within the visible light spectrum. The devices described herein may be advantageously packaged within a single integrated device or other solid state device, and/or employed in an integrated, single-camera medical imaging system, as well as many non-medical imaging systems that would benefit from simultaneous capture of visible-light wavelength images along with images at other wavelengths.

A novel optical investigation technique for railroad track inspection and assessment

NASA Astrophysics Data System (ADS)

Sabato, Alessandro; Beale, Christopher H.; Niezrecki, Christopher

2017-04-01

Track failures due to cross tie degradation or loss in ballast support may result in a number of problems ranging from simple service interruptions to derailments. Structural Health Monitoring (SHM) of railway track is important for safety reasons and to reduce downtime and maintenance costs. For this reason, novel and cost-effective track inspection technologies for assessing tracks' health are currently insufficient and needed. Advancements achieved in recent years in cameras technology, optical sensors, and image-processing algorithms have made machine vision, Structure from Motion (SfM), and three-dimensional (3D) Digital Image Correlation (DIC) systems extremely appealing techniques for extracting structural deformations and geometry profiles. Therefore, optically based, non-contact measurement techniques may be used for assessing surface defects, rail and tie deflection profiles, and ballast condition. In this study, the design of two camera-based measurement systems is proposed for crossties-ballast condition assessment and track examination purposes. The first one consists of four pairs of cameras installed on the underside of a rail car to detect the induced deformation and displacement on the whole length of the track's cross tie using 3D DIC measurement techniques. The second consists of another set of cameras using SfM techniques for obtaining a 3D rendering of the infrastructure from a series of two-dimensional (2D) images to evaluate the state of the track qualitatively. The feasibility of the proposed optical systems is evaluated through extensive laboratory tests, demonstrating their ability to measure parameters of interest (e.g. crosstie's full-field displacement, vertical deflection, shape, etc.) for assessment and SHM of railroad track.

Flow Interactions and Control

DTIC Science & Technology

2012-03-08

to-Use 3-D Camera For Measurements in Turbulent Flow Fields B Thurow, Auburn Near Mid Far Conventional imaging Plenoptic imaging Conventional 2...depth-of-field and blur  Reduced aperture (restricted angular information) leads to low signal levels Lightfield Imaging  Plenoptic camera records

Tenth Anniversary Image from Camera on NASA Mars Orbiter

NASA Image and Video Library

2012-02-29

NASA Mars Odyssey spacecraft captured this image on Feb. 19, 2012, 10 years to the day after the camera recorded its first view of Mars. This image covers an area in the Nepenthes Mensae region north of the Martian equator.

Full-Frame Reference for Test Photo of Moon

NASA Technical Reports Server (NTRS)

2005-01-01

This pair of views shows how little of the full image frame was taken up by the Moon in test images taken Sept. 8, 2005, by the High Resolution Imaging Science Experiment (HiRISE) camera on NASA's Mars Reconnaissance Orbiter. The Mars-bound camera imaged Earth's Moon from a distance of about 10 million kilometers (6 million miles) away -- 26 times the distance between Earth and the Moon -- as part of an activity to test and calibrate the camera. The images are very significant because they show that the Mars Reconnaissance Orbiter spacecraft and this camera can properly operate together to collect very high-resolution images of Mars. The target must move through the camera's telescope view in just the right direction and speed to acquire a proper image. The day's test images also demonstrate that the focus mechanism works properly with the telescope to produce sharp images.

Out of the 20,000-pixel-by-6,000-pixel full frame, the Moon's diameter is about 340 pixels, if the full Moon could be seen. The illuminated crescent is about 60 pixels wide, and the resolution is about 10 kilometers (6 miles) per pixel. At Mars, the entire image region will be filled with high-resolution information.

The Mars Reconnaissance Orbiter, launched on Aug. 12, 2005, is on course to reach Mars on March 10, 2006. After gradually adjusting the shape of its orbit for half a year, it will begin its primary science phase in November 2006. From the mission's planned science orbit about 300 kilometers (186 miles) above the surface of Mars, the high resolution camera will be able to discern features as small as one meter or yard across.

The Mars Reconnaissance Orbiter mission is managed by NASA's Jet Propulsion Laboratory, a division of the California Institute of Technology, Pasadena, for the NASA Science Mission Directorate. Lockheed Martin Space Systems, Denver, prime contractor for the project, built the spacecraft. Ball Aerospace & Technologies Corp., Boulder, Colo., built the High Resolution Imaging Science Experiment instrument for the University of Arizona, Tucson, to provide to the mission. The HiRISE Operations Center at the University of Arizona processes images from the camera.

The Galileo Solid-State Imaging experiment

USGS Publications Warehouse

Belton, M.J.S.; Klaasen, K.P.; Clary, M.C.; Anderson, J.L.; Anger, C.D.; Carr, M.H.; Chapman, C.R.; Davies, M.E.; Greeley, R.; Anderson, D.; Bolef, L.K.; Townsend, T.E.; Greenberg, R.; Head, J. W.; Neukum, G.; Pilcher, C.B.; Veverka, J.; Gierasch, P.J.; Fanale, F.P.; Ingersoll, A.P.; Masursky, H.; Morrison, D.; Pollack, James B.

1992-01-01

The Solid State Imaging (SSI) experiment on the Galileo Orbiter spacecraft utilizes a high-resolution (1500 mm focal length) television camera with an 800 ?? 800 pixel virtual-phase, charge-coupled detector. It is designed to return images of Jupiter and its satellites that are characterized by a combination of sensitivity levels, spatial resolution, geometric fiedelity, and spectral range unmatched by imaging data obtained previously. The spectral range extends from approximately 375 to 1100 nm and only in the near ultra-violet region (??? 350 nm) is the spectral coverage reduced from previous missions. The camera is approximately 100 times more sensitive than those used in the Voyager mission, and, because of the nature of the satellite encounters, will produce images with approximately 100 times the ground resolution (i.e., ??? 50 m lp-1) on the Galilean satellites. We describe aspects of the detector including its sensitivity to energetic particle radiation and how the requirements for a large full-well capacity and long-term stability in operating voltages led to the choice of the virtual phase chip. The F/8.5 camera system can reach point sources of V(mag) ??? 11 with S/N ??? 10 and extended sources with surface brightness as low as 20 kR in its highest gain state and longest exposure mode. We describe the performance of the system as determined by ground calibration and the improvements that have been made to the telescope (same basic catadioptric design that was used in Mariner 10 and the Voyager high-resolution cameras) to reduce the scattered light reaching the detector. The images are linearly digitized 8-bits deep and, after flat-fielding, are cosmetically clean. Information 'preserving' and 'non-preserving' on-board data compression capabilities are outlined. A special "summation" mode, designed for use deep in the Jovian radiation belts, near Io, is also described. The detector is 'preflashed' before each exposure to ensure the photometric linearity. The dynamic range is spread over 3 gain states and an exposure range from 4.17 ms to 51.2 s. A low-level of radial, third-order, geometric distortion has been measured in the raw images that is entirely due to the optical design. The distortion is of the pincushion type and amounts to about 1.2 pixels in the corners of the images. It is expected to be very stable. We discuss the measurement objectives of the SSI experiment in the Jupiter system and emphasize their relationships to those of other experiments in the Galileo project. We outline objectives for Jupiter atmospheric science, noting the relationship of SSI data to that to be returned by experiments on the atmospheric entry Probe. We also outline SSI objectives for satellite surfaces, ring structure, and 'darkside' (e.g., aurorae, lightning, etc.) experiments. Proposed cruise measurement objectives that relate to encounters at Venus, Moon, Earth, Gaspra, and, possibly, Ida are also briefly outlined. The article concludes with a description of a 'fully distributed' data analysis system (HIIPS) that SSI team members intend to use at their home institutions. We also list the nature of systematic data products that will become available to the scientific community. Finally, we append a short 'historical' note outlining the responsibilities and roles of institutions and individuals that have been involved in the 14 year development of the SSI experiment so far. ?? 1992 Kluwer Academic Publishers.

The PixFEL project: Progress towards a fine pitch X-ray imaging camera for next generation FEL facilities

NASA Astrophysics Data System (ADS)

Rizzo, G.; Batignani, G.; Benkechkache, M. A.; Bettarini, S.; Casarosa, G.; Comotti, D.; Dalla Betta, G.-F.; Fabris, L.; Forti, F.; Grassi, M.; Lodola, L.; Malcovati, P.; Manghisoni, M.; Mendicino, R.; Morsani, F.; Paladino, A.; Pancheri, L.; Paoloni, E.; Ratti, L.; Re, V.; Traversi, G.; Vacchi, C.; Verzellesi, G.; Xu, H.

2016-07-01

The INFN PixFEL project is developing the fundamental building blocks for a large area X-ray imaging camera to be deployed at next generation free electron laser (FEL) facilities with unprecedented intensity. Improvement in performance beyond the state of art in imaging instrumentation will be explored adopting advanced technologies like active edge sensors, a 65 nm node CMOS process and vertical integration. These are the key ingredients of the PixFEL project to realize a seamless large area focal plane instrument composed by a matrix of multilayer four-side buttable tiles. In order to minimize the dead area and reduce ambiguities in image reconstruction, a fine pitch active edge thick sensor is being optimized to cope with very high intensity photon flux, up to 104 photons per pixel, in the range from 1 to 10 keV. A low noise analog front-end channel with this wide dynamic range and a novel dynamic compression feature, together with a low power 10 bit analog to digital conversion up to 5 MHz, has been realized in a 110 μm pitch with a 65 nm CMOS process. Vertical interconnection of two CMOS tiers will be also explored in the future to build a four-side buttable readout chip with high density memories. In the long run the objective of the PixFEL project is to build a flexible X-ray imaging camera for operation both in burst mode, like at the European X-FEL, or in continuous mode with the high frame rates anticipated for future FEL facilities.

BOMBOLO: a Multi-Band, Wide-field, Near UV/Optical Imager for the SOAR 4m Telescope

NASA Astrophysics Data System (ADS)

Angeloni, R.; Guzmán, D.; Puzia, T. H.; Infante, L.

2014-10-01

BOMBOLO is a new multi-passband visitor instrument for SOAR observatory. The first fully Chilean instrument of its kind, it is a three-arms imager covering the near-UV and optical wavelengths. The three arms work simultaneously and independently, providing synchronized imaging capability for rapid astronomical events. BOMBOLO will be able to address largely unexplored events in the minute-to-second timescales, with the following leading science cases: 1) Simultaneous Multiband Flickering Studies of Accretion Phenomena; 2) Near UV/Optical Diagnostics of Stellar Evolutionary Phases; 3) Exoplanetary Transits and 4) Microlensing Follow-Up. BOMBOLO optical design consists of a wide field collimator feeding two dychroics at 390 and 550 nm. Each arm encompasses a camera, filter wheel and a science CCD230-42, imaging a 7 x 7 arcmin field of view onto a 2k x 2k image. The three CCDs will have different coatings to optimise the efficiencies of each camera. The detector controller to run the three cameras will be Torrent (the NOAO open-source system) and a PanView application will run the instrument and produce the data-cubes. The instrument is at Conceptual Design stage, having been approved by the SOAR Board of Directors as a visitor instrument in 2012 and having been granted full funding from CONICYT, the Chilean State Agency of Research, in 2013. The Design Phase is starting now and will be completed in late 2014, followed by a construction phase in 2015 and 2016A, with expected Commissioning in 2016B and 2017A.

Electronic cameras for low-light microscopy.

PubMed

Rasnik, Ivan; French, Todd; Jacobson, Ken; Berland, Keith

2013-01-01

This chapter introduces to electronic cameras, discusses the various parameters considered for evaluating their performance, and describes some of the key features of different camera formats. The chapter also presents the basic understanding of functioning of the electronic cameras and how these properties can be exploited to optimize image quality under low-light conditions. Although there are many types of cameras available for microscopy, the most reliable type is the charge-coupled device (CCD) camera, which remains preferred for high-performance systems. If time resolution and frame rate are of no concern, slow-scan CCDs certainly offer the best available performance, both in terms of the signal-to-noise ratio and their spatial resolution. Slow-scan cameras are thus the first choice for experiments using fixed specimens such as measurements using immune fluorescence and fluorescence in situ hybridization. However, if video rate imaging is required, one need not evaluate slow-scan CCD cameras. A very basic video CCD may suffice if samples are heavily labeled or are not perturbed by high intensity illumination. When video rate imaging is required for very dim specimens, the electron multiplying CCD camera is probably the most appropriate at this technological stage. Intensified CCDs provide a unique tool for applications in which high-speed gating is required. The variable integration time video cameras are very attractive options if one needs to acquire images at video rate acquisition, as well as with longer integration times for less bright samples. This flexibility can facilitate many diverse applications with highly varied light levels. Copyright © 2007 Elsevier Inc. All rights reserved.

Plume propagation direction determination with SO2 cameras

NASA Astrophysics Data System (ADS)

Klein, Angelika; Lübcke, Peter; Bobrowski, Nicole; Kuhn, Jonas; Platt, Ulrich

2017-03-01

SO2 cameras are becoming an established tool for measuring sulfur dioxide (SO2) fluxes in volcanic plumes with good precision and high temporal resolution. The primary result of SO2 camera measurements are time series of two-dimensional SO2 column density distributions (i.e. SO2 column density images). However, it is frequently overlooked that, in order to determine the correct SO2 fluxes, not only the SO2 column density, but also the distance between the camera and the volcanic plume, has to be precisely known. This is because cameras only measure angular extents of objects while flux measurements require knowledge of the spatial plume extent. The distance to the plume may vary within the image array (i.e. the field of view of the SO2 camera) since the plume propagation direction (i.e. the wind direction) might not be parallel to the image plane of the SO2 camera. If the wind direction and thus the camera-plume distance are not well known, this error propagates into the determined SO2 fluxes and can cause errors exceeding 50 %. This is a source of error which is independent of the frequently quoted (approximate) compensation of apparently higher SO2 column densities and apparently lower plume propagation velocities at non-perpendicular plume observation angles.Here, we propose a new method to estimate the propagation direction of the volcanic plume directly from SO2 camera image time series by analysing apparent flux gradients along the image plane. From the plume propagation direction and the known location of the SO2 source (i.e. volcanic vent) and camera position, the camera-plume distance can be determined. Besides being able to determine the plume propagation direction and thus the wind direction in the plume region directly from SO2 camera images, we additionally found that it is possible to detect changes of the propagation direction at a time resolution of the order of minutes. In addition to theoretical studies we applied our method to SO2 flux measurements at Mt Etna and demonstrate that we obtain considerably more precise (up to a factor of 2 error reduction) SO2 fluxes. We conclude that studies on SO2 flux variability become more reliable by excluding the possible influences of propagation direction variations.

Can we Use Low-Cost 360 Degree Cameras to Create Accurate 3d Models?

NASA Astrophysics Data System (ADS)

Barazzetti, L.; Previtali, M.; Roncoroni, F.

2018-05-01

360 degree cameras capture the whole scene around a photographer in a single shot. Cheap 360 cameras are a new paradigm in photogrammetry. The camera can be pointed to any direction, and the large field of view reduces the number of photographs. This paper aims to show that accurate metric reconstructions can be achieved with affordable sensors (less than 300 euro). The camera used in this work is the Xiaomi Mijia Mi Sphere 360, which has a cost of about 300 USD (January 2018). Experiments demonstrate that millimeter-level accuracy can be obtained during the image orientation and surface reconstruction steps, in which the solution from 360° images was compared to check points measured with a total station and laser scanning point clouds. The paper will summarize some practical rules for image acquisition as well as the importance of ground control points to remove possible deformations of the network during bundle adjustment, especially for long sequences with unfavorable geometry. The generation of orthophotos from images having a 360° field of view (that captures the entire scene around the camera) is discussed. Finally, the paper illustrates some case studies where the use of a 360° camera could be a better choice than a project based on central perspective cameras. Basically, 360° cameras become very useful in the survey of long and narrow spaces, as well as interior areas like small rooms.

A hands-free region-of-interest selection interface for solo surgery with a wide-angle endoscope: preclinical proof of concept.

PubMed

Jung, Kyunghwa; Choi, Hyunseok; Hong, Hanpyo; Adikrishna, Arnold; Jeon, In-Ho; Hong, Jaesung

2017-02-01

A hands-free region-of-interest (ROI) selection interface is proposed for solo surgery using a wide-angle endoscope. A wide-angle endoscope provides images with a larger field of view than a conventional endoscope. With an appropriate selection interface for a ROI, surgeons can also obtain a detailed local view as if they moved a conventional endoscope in a specific position and direction. To manipulate the endoscope without releasing the surgical instrument in hand, a mini-camera is attached to the instrument, and the images taken by the attached camera are analyzed. When a surgeon moves the instrument, the instrument orientation is calculated by an image processing. Surgeons can select the ROI with this instrument movement after switching from 'task mode' to 'selection mode.' The accelerated KAZE algorithm is used to track the features of the camera images once the instrument is moved. Both the wide-angle and detailed local views are displayed simultaneously, and a surgeon can move the local view area by moving the mini-camera attached to the surgical instrument. Local view selection for a solo surgery was performed without releasing the instrument. The accuracy of camera pose estimation was not significantly different between camera resolutions, but it was significantly different between background camera images with different numbers of features (P < 0.01). The success rate of ROI selection diminished as the number of separated regions increased. However, separated regions up to 12 with a region size of 160 × 160 pixels were selected with no failure. Surgical tasks on a phantom model and a cadaver were attempted to verify the feasibility in a clinical environment. Hands-free endoscope manipulation without releasing the instruments in hand was achieved. The proposed method requires only a small, low-cost camera and an image processing. The technique enables surgeons to perform solo surgeries without a camera assistant.

Autonomous vision-based navigation for proximity operations around binary asteroids

NASA Astrophysics Data System (ADS)

Gil-Fernandez, Jesus; Ortega-Hernando, Guillermo

2018-02-01

Future missions to small bodies demand higher level of autonomy in the Guidance, Navigation and Control system for higher scientific return and lower operational costs. Different navigation strategies have been assessed for ESA's asteroid impact mission (AIM). The main objective of AIM is the detailed characterization of binary asteroid Didymos. The trajectories for the proximity operations shall be intrinsically safe, i.e., no collision in presence of failures (e.g., spacecraft entering safe mode), perturbations (e.g., non-spherical gravity field), and errors (e.g., maneuver execution error). Hyperbolic arcs with sufficient hyperbolic excess velocity are designed to fulfil the safety, scientific, and operational requirements. The trajectory relative to the asteroid is determined using visual camera images. The ground-based trajectory prediction error at some points is comparable to the camera Field Of View (FOV). Therefore, some images do not contain the entire asteroid. Autonomous navigation can update the state of the spacecraft relative to the asteroid at higher frequency. The objective of the autonomous navigation is to improve the on-board knowledge compared to the ground prediction. The algorithms shall fit in off-the-shelf, space-qualified avionics. This note presents suitable image processing and relative-state filter algorithms for autonomous navigation in proximity operations around binary asteroids.

Autonomous vision-based navigation for proximity operations around binary asteroids

NASA Astrophysics Data System (ADS)

Gil-Fernandez, Jesus; Ortega-Hernando, Guillermo

2018-06-01

Future missions to small bodies demand higher level of autonomy in the Guidance, Navigation and Control system for higher scientific return and lower operational costs. Different navigation strategies have been assessed for ESA's asteroid impact mission (AIM). The main objective of AIM is the detailed characterization of binary asteroid Didymos. The trajectories for the proximity operations shall be intrinsically safe, i.e., no collision in presence of failures (e.g., spacecraft entering safe mode), perturbations (e.g., non-spherical gravity field), and errors (e.g., maneuver execution error). Hyperbolic arcs with sufficient hyperbolic excess velocity are designed to fulfil the safety, scientific, and operational requirements. The trajectory relative to the asteroid is determined using visual camera images. The ground-based trajectory prediction error at some points is comparable to the camera Field Of View (FOV). Therefore, some images do not contain the entire asteroid. Autonomous navigation can update the state of the spacecraft relative to the asteroid at higher frequency. The objective of the autonomous navigation is to improve the on-board knowledge compared to the ground prediction. The algorithms shall fit in off-the-shelf, space-qualified avionics. This note presents suitable image processing and relative-state filter algorithms for autonomous navigation in proximity operations around binary asteroids.

Data-Acquisition Software for PSP/TSP Wind-Tunnel Cameras

NASA Technical Reports Server (NTRS)

Amer, Tahani R.; Goad, William K.

2005-01-01

Wing-Viewer is a computer program for acquisition and reduction of image data acquired by any of five different scientificgrade commercial electronic cameras used at Langley Research center to observe wind-tunnel models coated with pressure or temperature-sensitive paints (PSP/TSP). Wing-Viewer provides full automation of camera operation and acquisition of image data, and has limited data-preprocessing capability for quick viewing of the results of PSP/TSP test images. Wing- Viewer satisfies a requirement for a standard interface between all the cameras and a single personal computer: Written by use of Microsoft Visual C++ and the Microsoft Foundation Class Library as a framework, Wing-Viewer has the ability to communicate with the C/C++ software libraries that run on the controller circuit cards of all five cameras.

Integration of USB and firewire cameras in machine vision applications

NASA Astrophysics Data System (ADS)

Smith, Timothy E.; Britton, Douglas F.; Daley, Wayne D.; Carey, Richard

1999-08-01

Digital cameras have been around for many years, but a new breed of consumer market cameras is hitting the main stream. By using these devices, system designers and integrators will be well posited to take advantage of technological advances developed to support multimedia and imaging applications on the PC platform. Having these new cameras on the consumer market means lower cost, but it does not necessarily guarantee ease of integration. There are many issues that need to be accounted for like image quality, maintainable frame rates, image size and resolution, supported operating system, and ease of software integration. This paper will describe briefly a couple of the consumer digital standards, and then discuss some of the advantages and pitfalls of integrating both USB and Firewire cameras into computer/machine vision applications.

Modulated CMOS camera for fluorescence lifetime microscopy.

PubMed

Chen, Hongtao; Holst, Gerhard; Gratton, Enrico

2015-12-01

Widefield frequency-domain fluorescence lifetime imaging microscopy (FD-FLIM) is a fast and accurate method to measure the fluorescence lifetime of entire images. However, the complexity and high costs involved in construction of such a system limit the extensive use of this technique. PCO AG recently released the first luminescence lifetime imaging camera based on a high frequency modulated CMOS image sensor, QMFLIM2. Here we tested and provide operational procedures to calibrate the camera and to improve the accuracy using corrections necessary for image analysis. With its flexible input/output options, we are able to use a modulated laser diode or a 20 MHz pulsed white supercontinuum laser as the light source. The output of the camera consists of a stack of modulated images that can be analyzed by the SimFCS software using the phasor approach. The nonuniform system response across the image sensor must be calibrated at the pixel level. This pixel calibration is crucial and needed for every camera settings, e.g. modulation frequency and exposure time. A significant dependency of the modulation signal on the intensity was also observed and hence an additional calibration is needed for each pixel depending on the pixel intensity level. These corrections are important not only for the fundamental frequency, but also for the higher harmonics when using the pulsed supercontinuum laser. With these post data acquisition corrections, the PCO CMOS-FLIM camera can be used for various biomedical applications requiring a large frame and high speed acquisition. © 2015 Wiley Periodicals, Inc.

Research on auto-calibration technology of the image plane's center of 360-degree and all round looking camera

NASA Astrophysics Data System (ADS)

Zhang, Shaojun; Xu, Xiping

2015-10-01

The 360-degree and all round looking camera, as its characteristics of suitable for automatic analysis and judgment on the ambient environment of the carrier by image recognition algorithm, is usually applied to opto-electronic radar of robots and smart cars. In order to ensure the stability and consistency of image processing results of mass production, it is necessary to make sure the centers of image planes of different cameras are coincident, which requires to calibrate the position of the image plane's center. The traditional mechanical calibration method and electronic adjusting mode of inputting the offsets manually, both exist the problem of relying on human eyes, inefficiency and large range of error distribution. In this paper, an approach of auto- calibration of the image plane of this camera is presented. The imaging of the 360-degree and all round looking camera is a ring-shaped image consisting of two concentric circles, the center of the image is a smaller circle and the outside is a bigger circle. The realization of the technology is just to exploit the above characteristics. Recognizing the two circles through HOUGH TRANSFORM algorithm and calculating the center position, we can get the accurate center of image, that the deviation of the central location of the optic axis and image sensor. The program will set up the image sensor chip through I2C bus automatically, we can adjusting the center of the image plane automatically and accurately. The technique has been applied to practice, promotes productivity and guarantees the consistent quality of products.

Human body thermal images generated by conduction or radiation heat

NASA Astrophysics Data System (ADS)

Gavriloaia, Gheorghe; Sofron, Emil; Fumarel, Radu

2009-01-01

Humans and animals in general, are usually in a thermal steady state with respect to their surroundings. The tissues heat, generated at normal or diseases states, is lost to environment though several mechanisms: radiation, conduction, convection, evaporation, etc. Skin temperature is not the same on the entire body and a thermal body signature can be got. The temperature at skin level was measured by a thermistor, conduction component and by an IR camera, radiation component. A theoretical analysis using Weinhaum and JIJI model was done. The three images are investigated in order to get a cheap method for the early cancer diagnosis.

Use of a color CMOS camera as a colorimeter

NASA Astrophysics Data System (ADS)

Dallas, William J.; Roehrig, Hans; Redford, Gary R.

2006-08-01

In radiology diagnosis, film is being quickly replaced by computer monitors as the display medium for all imaging modalities. Increasingly, these monitors are color instead of monochrome. It is important to have instruments available to characterize the display devices in order to guarantee reproducible presentation of image material. We are developing an imaging colorimeter based on a commercially available color digital camera. The camera uses a sensor that has co-located pixels in all three primary colors.

Demonstration of the CDMA-mode CAOS smart camera.

PubMed

Riza, Nabeel A; Mazhar, Mohsin A

2017-12-11

Demonstrated is the code division multiple access (CDMA)-mode coded access optical sensor (CAOS) smart camera suited for bright target scenarios. Deploying a silicon CMOS sensor and a silicon point detector within a digital micro-mirror device (DMD)-based spatially isolating hybrid camera design, this smart imager first engages the DMD starring mode with a controlled factor of 200 high optical attenuation of the scene irradiance to provide a classic unsaturated CMOS sensor-based image for target intelligence gathering. Next, this CMOS sensor provided image data is used to acquire a focused zone more robust un-attenuated true target image using the time-modulated CDMA-mode of the CAOS camera. Using four different bright light test target scenes, successfully demonstrated is a proof-of-concept visible band CAOS smart camera operating in the CDMA-mode using up-to 4096 bits length Walsh design CAOS pixel codes with a maximum 10 KHz code bit rate giving a 0.4096 seconds CAOS frame acquisition time. A 16-bit analog-to-digital converter (ADC) with time domain correlation digital signal processing (DSP) generates the CDMA-mode images with a 3600 CAOS pixel count and a best spatial resolution of one micro-mirror square pixel size of 13.68 μm side. The CDMA-mode of the CAOS smart camera is suited for applications where robust high dynamic range (DR) imaging is needed for un-attenuated un-spoiled bright light spectrally diverse targets.

Pentacam Scheimpflug quantitative imaging of the crystalline lens and intraocular lens.

PubMed

Rosales, Patricia; Marcos, Susana

2009-05-01

To implement geometrical and optical distortion correction methods for anterior segment Scheimpflug images obtained with a commercially available system (Pentacam, Oculus Optikgeräte GmbH). Ray tracing algorithms were implemented to obtain corrected ocular surface geometry from the original images captured by the Pentacam's CCD camera. As details of the optical layout were not fully provided by the manufacturer, an iterative procedure (based on imaging of calibrated spheres) was developed to estimate the camera lens specifications. The correction procedure was tested on Scheimpflug images of a physical water cell model eye (with polymethylmethacrylate cornea and a commercial IOL of known dimensions) and of a normal human eye previously measured with a corrected optical and geometrical distortion Scheimpflug camera (Topcon SL-45 [Topcon Medical Systems Inc] from the Vrije University, Amsterdam, Holland). Uncorrected Scheimpflug images show flatter surfaces and thinner lenses than in reality. The application of geometrical and optical distortion correction algorithms improves the accuracy of the estimated anterior lens radii of curvature by 30% to 40% and of the estimated posterior lens by 50% to 100%. The average error in the retrieved radii was 0.37 and 0.46 mm for the anterior and posterior lens radii of curvature, respectively, and 0.048 mm for lens thickness. The Pentacam Scheimpflug system can be used to obtain quantitative information on the geometry of the crystalline lens, provided that geometrical and optical distortion correction algorithms are applied, within the accuracy of state-of-the art phakometry and biometry. The techniques could improve with exact knowledge of the technical specifications of the instrument, improved edge detection algorithms, consideration of aspheric and non-rotationally symmetrical surfaces, and introduction of a crystalline gradient index.

Feasibility of a high-speed gamma-camera design using the high-yield-pileup-event-recovery method.

PubMed

Wong, W H; Li, H; Uribe, J; Baghaei, H; Wang, Y; Yokoyama, S

2001-04-01

Higher count-rate gamma cameras than are currently used are needed if the technology is to fulfill its promise in positron coincidence imaging, radionuclide therapy dosimetry imaging, and cardiac first-pass imaging. The present single-crystal design coupled with conventional detector electronics and the traditional Anger-positioning algorithm hinder higher count-rate imaging because of the pileup of gamma-ray signals in the detector and electronics. At an interaction rate of 2 million events per second, the fraction of nonpileup events is < 20% of the total incident events. Hence, the recovery of pileup events can significantly increase the count-rate capability, increase the yield of imaging photons, and minimize image artifacts associated with pileups. A new technology to significantly enhance the performance of gamma cameras in this area is introduced. We introduce a new electronic design called high-yield-pileup-event-recovery (HYPER) electronics for processing the detector signal in gamma cameras so that the individual gamma energies and positions of pileup events, including multiple pileups, can be resolved and recovered despite the mixing of signals. To illustrate the feasibility of the design concept, we have developed a small gamma-camera prototype with the HYPER-Anger electronics. The camera has a 10 x 10 x 1 cm NaI(Tl) crystal with four photomultipliers. Hot-spot and line sources with very high 99mTc activities were imaged. The phantoms were imaged continuously from 60,000 to 3,500,000 counts per second to illustrate the efficacy of the method as a function of counting rates. At 2-3 million events per second, all phantoms were imaged with little distortion, pileup, and dead-time loss. At these counting rates, multiple pileup events (> or = 3 events piling together) were the predominate occurrences, and the HYPER circuit functioned well to resolve and recover these events. The full width at half maximum of the line-spread function at 3,000,000 counts per second was 1.6 times that at 60,000 counts per second. This feasibility study showed that the HYPER electronic concept works; it can significantly increase the count-rate capability and dose efficiency of gamma cameras. In a larger clinical camera, multiple HYPER-Anger circuits may be implemented to further improve the imaging counting rates that we have shown by multiple times. This technology would facilitate the use of gamma cameras for radionuclide therapy dosimetry imaging, cardiac first-pass imaging, and positron coincidence imaging and the simultaneous acquisition of transmission and emission data using different isotopes with less cross-contamination between transmission and emission data.

High-resolution ophthalmic imaging system

DOEpatents

Olivier, Scot S.; Carrano, Carmen J.

2007-12-04

A system for providing an improved resolution retina image comprising an imaging camera for capturing a retina image and a computer system operatively connected to the imaging camera, the computer producing short exposures of the retina image and providing speckle processing of the short exposures to provide the improved resolution retina image. The system comprises the steps of capturing a retina image, producing short exposures of the retina image, and speckle processing the short exposures of the retina image to provide the improved resolution retina image.

Blood pulsation measurement using cameras operating in visible light: limitations.

PubMed

Koprowski, Robert

2016-10-03

The paper presents an automatic method for analysis and processing of images from a camera operating in visible light. This analysis applies to images containing the human facial area (body) and enables to measure the blood pulse rate. Special attention was paid to the limitations of this measurement method taking into account the possibility of using consumer cameras in real conditions (different types of lighting, different camera resolution, camera movement). The proposed new method of image analysis and processing was associated with three stages: (1) image pre-processing-allowing for the image filtration and stabilization (object location tracking); (2) main image processing-allowing for segmentation of human skin areas, acquisition of brightness changes; (3) signal analysis-filtration, FFT (Fast Fourier Transformation) analysis, pulse calculation. The presented algorithm and method for measuring the pulse rate has the following advantages: (1) it allows for non-contact and non-invasive measurement; (2) it can be carried out using almost any camera, including webcams; (3) it enables to track the object on the stage, which allows for the measurement of the heart rate when the patient is moving; (4) for a minimum of 40,000 pixels, it provides a measurement error of less than ±2 beats per minute for p < 0.01 and sunlight, or a slightly larger error (±3 beats per minute) for artificial lighting; (5) analysis of a single image takes about 40 ms in Matlab Version 7.11.0.584 (R2010b) with Image Processing Toolbox Version 7.1 (R2010b).

Variable high-resolution color CCD camera system with online capability for professional photo studio application

NASA Astrophysics Data System (ADS)

Breitfelder, Stefan; Reichel, Frank R.; Gaertner, Ernst; Hacker, Erich J.; Cappellaro, Markus; Rudolf, Peter; Voelk, Ute

1998-04-01

Digital cameras are of increasing significance for professional applications in photo studios where fashion, portrait, product and catalog photographs or advertising photos of high quality have to be taken. The eyelike is a digital camera system which has been developed for such applications. It is capable of working online with high frame rates and images of full sensor size and it provides a resolution that can be varied between 2048 by 2048 and 6144 by 6144 pixel at a RGB color depth of 12 Bit per channel with an also variable exposure time of 1/60s to 1s. With an exposure time of 100 ms digitization takes approx. 2 seconds for an image of 2048 by 2048 pixels (12 Mbyte), 8 seconds for the image of 4096 by 4096 pixels (48 Mbyte) and 40 seconds for the image of 6144 by 6144 pixels (108 MByte). The eyelike can be used in various configurations. Used as a camera body most commercial lenses can be connected to the camera via existing lens adaptors. On the other hand the eyelike can be used as a back to most commercial 4' by 5' view cameras. This paper describes the eyelike camera concept with the essential system components. The article finishes with a description of the software, which is needed to bring the high quality of the camera to the user.

Rover mast calibration, exact camera pointing, and camara handoff for visual target tracking

NASA Technical Reports Server (NTRS)

Kim, Won S.; Ansar, Adnan I.; Steele, Robert D.

2005-01-01

This paper presents three technical elements that we have developed to improve the accuracy of the visual target tracking for single-sol approach-and-instrument placement in future Mars rover missions. An accurate, straightforward method of rover mast calibration is achieved by using a total station, a camera calibration target, and four prism targets mounted on the rover. The method was applied to Rocky8 rover mast calibration and yielded a 1.1-pixel rms residual error. Camera pointing requires inverse kinematic solutions for mast pan and tilt angles such that the target image appears right at the center of the camera image. Two issues were raised. Mast camera frames are in general not parallel to the masthead base frame. Further, the optical axis of the camera model in general does not pass through the center of the image. Despite these issues, we managed to derive non-iterative closed-form exact solutions, which were verified with Matlab routines. Actual camera pointing experiments aver 50 random target image paints yielded less than 1.3-pixel rms pointing error. Finally, a purely geometric method for camera handoff using stereo views of the target has been developed. Experimental test runs show less than 2.5 pixels error on high-resolution Navcam for Pancam-to-Navcam handoff, and less than 4 pixels error on lower-resolution Hazcam for Navcam-to-Hazcam handoff.

Thermographic measurements of high-speed metal cutting

NASA Astrophysics Data System (ADS)

Mueller, Bernhard; Renz, Ulrich

2002-03-01

Thermographic measurements of a high-speed cutting process have been performed with an infrared camera. To realize images without motion blur the integration times were reduced to a few microseconds. Since the high tool wear influences the measured temperatures a set-up has been realized which enables small cutting lengths. Only single images have been recorded because the process is too fast to acquire a sequence of images even with the frame rate of the very fast infrared camera which has been used. To expose the camera when the rotating tool is in the middle of the camera image an experimental set-up with a light barrier and a digital delay generator with a time resolution of 1 ns has been realized. This enables a very exact triggering of the camera at the desired position of the tool in the image. Since the cutting depth is between 0.1 and 0.2 mm a high spatial resolution was also necessary which was obtained by a special close-up lens allowing a resolution of app. 45 microns. The experimental set-up will be described and infrared images and evaluated temperatures of a titanium alloy and a carbon steel will be presented for cutting speeds up to 42 m/s.

Thermal feature extraction of servers in a datacenter using thermal image registration

NASA Astrophysics Data System (ADS)

Liu, Hang; Ran, Jian; Xie, Ting; Gao, Shan

2017-09-01

Thermal cameras provide fine-grained thermal information that enhances monitoring and enables automatic thermal management in large datacenters. Recent approaches employing mobile robots or thermal camera networks can already identify the physical locations of hot spots. Other distribution information used to optimize datacenter management can also be obtained automatically using pattern recognition technology. However, most of the features extracted from thermal images, such as shape and gradient, may be affected by changes in the position and direction of the thermal camera. This paper presents a method for extracting the thermal features of a hot spot or a server in a container datacenter. First, thermal and visual images are registered based on textural characteristics extracted from images acquired in datacenters. Then, the thermal distribution of each server is standardized. The features of a hot spot or server extracted from the standard distribution can reduce the impact of camera position and direction. The results of experiments show that image registration is efficient for aligning the corresponding visual and thermal images in the datacenter, and the standardization procedure reduces the impacts of camera position and direction on hot spot or server features.

In vitro near-infrared imaging of occlusal dental caries using a germanium-enhanced CMOS camera

NASA Astrophysics Data System (ADS)

Lee, Chulsung; Darling, Cynthia L.; Fried, Daniel

2010-02-01

The high transparency of dental enamel in the near-infrared (NIR) at 1310-nm can be exploited for imaging dental caries without the use of ionizing radiation. The objective of this study was to determine whether the lesion contrast derived from NIR transillumination can be used to estimate lesion severity. Another aim was to compare the performance of a new Ge enhanced complementary metal-oxide-semiconductor (CMOS) based NIR imaging camera with the InGaAs focal plane array (FPA). Extracted human teeth (n=52) with natural occlusal caries were imaged with both cameras at 1310-nm and the image contrast between sound and carious regions was calculated. After NIR imaging, teeth were sectioned and examined using more established methods, namely polarized light microscopy (PLM) and transverse microradiography (TMR) to calculate lesion severity. Lesions were then classified into 4 categories according to the lesion severity. Lesion contrast increased significantly with lesion severity for both cameras (p<0.05). The Ge enhanced CMOS camera equipped with the larger array and smaller pixels yielded higher contrast values compared with the smaller InGaAs FPA (p<0.01). Results demonstrate that NIR lesion contrast can be used to estimate lesion severity.

In vitro near-infrared imaging of occlusal dental caries using germanium enhanced CMOS camera.

PubMed

Lee, Chulsung; Darling, Cynthia L; Fried, Daniel

2010-03-01

The high transparency of dental enamel in the near-infrared (NIR) at 1310-nm can be exploited for imaging dental caries without the use of ionizing radiation. The objective of this study was to determine whether the lesion contrast derived from NIR transillumination can be used to estimate lesion severity. Another aim was to compare the performance of a new Ge enhanced complementary metal-oxide-semiconductor (CMOS) based NIR imaging camera with the InGaAs focal plane array (FPA). Extracted human teeth (n=52) with natural occlusal caries were imaged with both cameras at 1310-nm and the image contrast between sound and carious regions was calculated. After NIR imaging, teeth were sectioned and examined using more established methods, namely polarized light microscopy (PLM) and transverse microradiography (TMR) to calculate lesion severity. Lesions were then classified into 4 categories according to the lesion severity. Lesion contrast increased significantly with lesion severity for both cameras (p<0.05). The Ge enhanced CMOS camera equipped with the larger array and smaller pixels yielded higher contrast values compared with the smaller InGaAs FPA (p<0.01). Results demonstrate that NIR lesion contrast can be used to estimate lesion severity.

An optimal algorithm for reconstructing images from binary measurements

NASA Astrophysics Data System (ADS)

Yang, Feng; Lu, Yue M.; Sbaiz, Luciano; Vetterli, Martin

2010-01-01

We have studied a camera with a very large number of binary pixels referred to as the gigavision camera [1] or the gigapixel digital film camera [2, 3]. Potential advantages of this new camera design include improved dynamic range, thanks to its logarithmic sensor response curve, and reduced exposure time in low light conditions, due to its highly sensitive photon detection mechanism. We use maximum likelihood estimator (MLE) to reconstruct a high quality conventional image from the binary sensor measurements of the gigavision camera. We prove that when the threshold T is "1", the negative loglikelihood function is a convex function. Therefore, optimal solution can be achieved using convex optimization. Base on filter bank techniques, fast algorithms are given for computing the gradient and the multiplication of a vector and Hessian matrix of the negative log-likelihood function. We show that with a minor change, our algorithm also works for estimating conventional images from multiple binary images. Numerical experiments with synthetic 1-D signals and images verify the effectiveness and quality of the proposed algorithm. Experimental results also show that estimation performance can be improved by increasing the oversampling factor or the number of binary images.

A blur-invariant local feature for motion blurred image matching

NASA Astrophysics Data System (ADS)

Tong, Qiang; Aoki, Terumasa

2017-07-01

Image matching between a blurred (caused by camera motion, out of focus, etc.) image and a non-blurred image is a critical task for many image/video applications. However, most of the existing local feature schemes fail to achieve this work. This paper presents a blur-invariant descriptor and a novel local feature scheme including the descriptor and the interest point detector based on moment symmetry - the authors' previous work. The descriptor is based on a new concept - center peak moment-like element (CPME) which is robust to blur and boundary effect. Then by constructing CPMEs, the descriptor is also distinctive and suitable for image matching. Experimental results show our scheme outperforms state of the art methods for blurred image matching

Curiosity ChemCam Removes Dust

NASA Image and Video Library

2013-04-08

This pair of images taken a few minutes apart show how laser firing by NASA Mars rover Curiosity removes dust from the surface of a rock. The images were taken by the remote micro-imager camera in the laser-firing Chemistry and Camera ChemCam.

Mid-latitude response to geomagnetic storms observed in 630nm airglow over continental United States

NASA Astrophysics Data System (ADS)

Bhatt, A.; Kendall, E. A.

2016-12-01

We present analysis of mid-latitude response observed to geomagnetic storms using the MANGO network consisting of all-sky cameras imaging 630nm emission over the continental United States. The response largely falls in two categories: Stable Auroral Red (SAR) arc and Large-scale traveling ionospheric disturbances (LSTIDs). However, outside of these phenomena, less often observed response include anomalous airglow brightening, bright swirls, and frozen in traveling structures. We will present an analysis of various events observed over 3 years of MANGO network operation, which started with two imagers in the western US with addition of new imagers in the last year. We will also present unusual north and northeastward propagating waves often observed in conjunction with diffuse aurora. Wherever possible, we will compare with observations from Boston University imagers located in Massachusetts and Texas.

What Is an Image?

ERIC Educational Resources Information Center

Zetie, K. P.

2017-01-01

In basic physics, often in their first year of study of the subject, students meet the concept of an image, for example when using pinhole cameras and finding the position of an image in a mirror. They are also familiar with the term in photography and design, through software which allows image manipulation, even "in-camera" on most…

SPLASSH: Open source software for camera-based high-speed, multispectral in-vivo optical image acquisition

PubMed Central

Sun, Ryan; Bouchard, Matthew B.; Hillman, Elizabeth M. C.

2010-01-01

Camera-based in-vivo optical imaging can provide detailed images of living tissue that reveal structure, function, and disease. High-speed, high resolution imaging can reveal dynamic events such as changes in blood flow and responses to stimulation. Despite these benefits, commercially available scientific cameras rarely include software that is suitable for in-vivo imaging applications, making this highly versatile form of optical imaging challenging and time-consuming to implement. To address this issue, we have developed a novel, open-source software package to control high-speed, multispectral optical imaging systems. The software integrates a number of modular functions through a custom graphical user interface (GUI) and provides extensive control over a wide range of inexpensive IEEE 1394 Firewire cameras. Multispectral illumination can be incorporated through the use of off-the-shelf light emitting diodes which the software synchronizes to image acquisition via a programmed microcontroller, allowing arbitrary high-speed illumination sequences. The complete software suite is available for free download. Here we describe the software’s framework and provide details to guide users with development of this and similar software. PMID:21258475

Capturing the plenoptic function in a swipe

NASA Astrophysics Data System (ADS)

Lawson, Michael; Brookes, Mike; Dragotti, Pier Luigi

2016-09-01

Blur in images, caused by camera motion, is typically thought of as a problem. The approach described in this paper shows instead that it is possible to use the blur caused by the integration of light rays at different positions along a moving camera trajectory to extract information about the light rays present within the scene. Retrieving the light rays of a scene from different viewpoints is equivalent to retrieving the plenoptic function of the scene. In this paper, we focus on a specific case in which the blurred image of a scene, containing a flat plane with a texture signal that is a sum of sine waves, is analysed to recreate the plenoptic function. The image is captured by a single lens camera with shutter open, moving in a straight line between two points, resulting in a swiped image. It is shown that finite rate of innovation sampling theory can be used to recover the scene geometry and therefore the epipolar plane image from the single swiped image. This epipolar plane image can be used to generate unblurred images for a given camera location.

Lymphoscintigraphy

MedlinePlus

... The special camera and imaging techniques used in nuclear medicine include the gamma camera and single-photon emission-computed tomography (SPECT). The gamma camera, also called a scintillation camera, detects radioactive energy that is emitted from the patient's body and ...

Hepatobiliary

MedlinePlus

... The special camera and imaging techniques used in nuclear medicine include the gamma camera and single-photon emission-computed tomography (SPECT). The gamma camera, also called a scintillation camera, detects radioactive energy that is emitted from the patient's body and ...

Presence capture cameras - a new challenge to the image quality

NASA Astrophysics Data System (ADS)

Peltoketo, Veli-Tapani

2016-04-01

Commercial presence capture cameras are coming to the markets and a new era of visual entertainment starts to get its shape. Since the true presence capturing is still a very new technology, the real technical solutions are just passed a prototyping phase and they vary a lot. Presence capture cameras have still the same quality issues to tackle as previous phases of digital imaging but also numerous new ones. This work concentrates to the quality challenges of presence capture cameras. A camera system which can record 3D audio-visual reality as it is has to have several camera modules, several microphones and especially technology which can synchronize output of several sources to a seamless and smooth virtual reality experience. Several traditional quality features are still valid in presence capture cameras. Features like color fidelity, noise removal, resolution and dynamic range create the base of virtual reality stream quality. However, co-operation of several cameras brings a new dimension for these quality factors. Also new quality features can be validated. For example, how the camera streams should be stitched together with 3D experience without noticeable errors and how to validate the stitching? The work describes quality factors which are still valid in the presence capture cameras and defines the importance of those. Moreover, new challenges of presence capture cameras are investigated in image and video quality point of view. The work contains considerations how well current measurement methods can be used in presence capture cameras.

Digital photorefraction

NASA Astrophysics Data System (ADS)

Costa, Manuel F. M.; Jorge, Jorge M.

1998-01-01

The early evaluation of the visual status of human infants is of a critical importance. It is of utmost importance to the development of the child's visual system that she perceives clear, focused, retinal images. Furthermore if the refractive problems are not corrected in due time amblyopia may occur. Photorefraction is a non-invasive clinical tool rather convenient for application to this kind of population. A qualitative or semi-quantitative information about refractive errors, accommodation, strabismus, amblyogenic factors and some pathologies (cataracts) can the easily obtained. The photorefraction experimental setup we established using new technological breakthroughs on the fields of imaging devices, image processing and fiber optics, allows the implementation of both the isotropic and eccentric photorefraction approaches. Essentially both methods consist on delivering a light beam into the eyes. It is refracted by the ocular media, strikes the retina, focusing or not, reflects off and is collected by a camera. The system is formed by one CCD color camera and a light source. A beam splitter in front of the camera's objective allows coaxial illumination and observation. An optomechanical system also allows eccentric illumination. The light source is a flash type one and is synchronized with the camera's image acquisition. The camera's image is digitized displayed in real time. Image processing routines are applied for image's enhancement and feature extraction.

Digital photorefraction

NASA Astrophysics Data System (ADS)

Costa, Manuel F.; Jorge, Jorge M.

1997-12-01

The early evaluation of the visual status of human infants is of a critical importance. It is of utmost importance to the development of the child's visual system that she perceives clear, focused, retinal images. Furthermore if the refractive problems are not corrected in due time amblyopia may occur. Photorefraction is a non-invasive clinical tool rather convenient for application to this kind of population. A qualitative or semi-quantitative information about refractive errors, accommodation, strabismus, amblyogenic factors and some pathologies (cataracts) can the easily obtained. The photorefraction experimental setup we established using new technological breakthroughs on the fields of imaging devices, image processing and fiber optics, allows the implementation of both the isotropic and eccentric photorefraction approaches. Essentially both methods consist on delivering a light beam into the eyes. It is refracted by the ocular media, strikes the retina, focusing or not, reflects off and is collected by a camera. The system is formed by one CCD color camera and a light source. A beam splitter in front of the camera's objective allows coaxial illumination and observation. An optomechanical system also allows eccentric illumination. The light source is a flash type one and is synchronized with the camera's image acquisition. The camera's image is digitized displayed in real time. Image processing routines are applied for image's enhancement and feature extraction.

Reconstruction of refocusing and all-in-focus images based on forward simulation model of plenoptic camera

NASA Astrophysics Data System (ADS)

Zhang, Rumin; Liu, Peng; Liu, Dijun; Su, Guobin

2015-12-01

In this paper, we establish a forward simulation model of plenoptic camera which is implemented by inserting a micro-lens array in a conventional camera. The simulation model is used to emulate how the space objects at different depths are imaged by the main lens then remapped by the micro-lens and finally captured on the 2D sensor. We can easily modify the parameters of the simulation model such as the focal lengths and diameters of the main lens and micro-lens and the number of micro-lens. Employing the spatial integration, the refocused images and all-in-focus images are rendered based on the plenoptic images produced by the model. The forward simulation model can be used to determine the trade-offs between different configurations and to test any new researches related to plenoptic camera without the need of prototype.

Depth profile measurement with lenslet images of the plenoptic camera

NASA Astrophysics Data System (ADS)

Yang, Peng; Wang, Zhaomin; Zhang, Wei; Zhao, Hongying; Qu, Weijuan; Zhao, Haimeng; Asundi, Anand; Yan, Lei

2018-03-01

An approach for carrying out depth profile measurement of an object with the plenoptic camera is proposed. A single plenoptic image consists of multiple lenslet images. To begin with, these images are processed directly with a refocusing technique to obtain the depth map, which does not need to align and decode the plenoptic image. Then, a linear depth calibration is applied based on the optical structure of the plenoptic camera for depth profile reconstruction. One significant improvement of the proposed method concerns the resolution of the depth map. Unlike the traditional method, our resolution is not limited by the number of microlenses inside the camera, and the depth map can be globally optimized. We validated the method with experiments on depth map reconstruction, depth calibration, and depth profile measurement, with the results indicating that the proposed approach is both efficient and accurate.