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6th ASME International conference on Energy Sustainability

作者： Pena-Cruz, Manuel I. Arancibia-Bulnes, Camilo A. Iriarte-Cornejo, Cuitlahuac Cabanillas, Rafael E. Estrada, Claudio A. Ctr Invest Energia UNAM Temixco Morelos Mexico UNISON Dept Ingn Quim Met Hermosillo Sonora Mexico

ISBN: (纸本)9780791844816

In the framework of the National Laboratory of Solar Concentrating and Solar Chemistry systems (LACYQS, for its Spanish acronym), a Heliostat Test Field (HTF) was built in Mexico. This research facility is located 10 km away from the city of Hermosillo, in the state of Sonora. The main purpose of the HTF, at the present stage, is to serve as platform for the development and testing of heliostat technology. In order to evaluate the performance of heliostats, various optical tests have been implemented. In the sun tracking test, the heliostat is operated as a solar tracker. A camera is attached to the heliostat, which is pointed directly to the sun. Images are captured throughout the day to quantify the wandering of the solar disc in the image. In the reflected spot test, the image produced on the Lambertian target by the concentrating heliostat, due to the reflection of the sun, is recorded by a CCD camera throughout the day. Image processing algorithms. calculate the centroid of energy of the image and evaluate the position and wandering across the white screen at all times. After this information is gathered, and the influence of wind and external factors eliminated, data are interpreted to characterize the behavior of solar projection algorithms and mechanical components. In the fringe projection analysis, also known as deflectometry, fringe patters are projected at night on a Lambertian target. The image of the pattern reflected by the heliostat is recorded with a camera. Distortions in the fringes, due to mirror stress and canting, allows the characterization of the surface error of the facets.

关键词： CCD cameras

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Iris-biometric comparators: Exploiting comparison scores towards an optimal alignment under Gaussian assumption

Iris-biometric comparators: Exploiting comparison scores tow...

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2012 5th IAPR International conference on Biometrics, ICB 2012

作者： Rathgeb, Christian Uhl, Andreas Wild, Peter Multimedia Signal Processing and Security Lab Department of Computer Sciences University of Salzburg Austria

ISBN: (纸本)9781467303941

Iris-based systems guarantee a level of security and identity protection that is unparalleled by any other biometric. In past years numerous iris recognition algorithms have been proposed revealing impressive recognition rates. While the vast majority of research is focused on extracting highly discriminative feature vectors potential improvements in biometric comparators are commonly neglected. In this paper a new strategy for comparing binary biometric templates, in particular iris-codes, is presented. Instead of optimally aligning two iris-codes by maximizing the comparison score for several bit shifts utilizes the total series of comparison scores, avoiding any information loss. The soundness of the approach, which requires marginal additional computational effort, is confirmed by experiments applying two different iris-biometric feature extraction algorithms. © 2012 IEEE.

关键词： Comparators (optical)

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Robust Recognition of 1-D Barcodes Using Hough Transform

Robust Recognition of 1-D Barcodes Using Hough Transform

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conference on Image processing - Machine vision Applications V

作者： Dwinell, John Bian, Peng Bian, Long Xiang SICK Inc. (United States) Microsoft Corp. (China)

ISBN: (纸本)9780819489470

In this paper we present an algorithm for the recognition of 1D barcodes using the Hough transform, which is highly robust regarding the typical degraded image. The algorithm addresses various typical image distortions, such as inhomogeneous illumination, reflections, damaged barcode or blurriness etc. Other problems arise from recognizing low quality printing (low contrast or poor ink receptivity). Traditional approaches are unable to provide a fast solution for handling such complex and mixed noise factors. A multi-level method offers a better approach to best manage competing constraints of complex noise and fast decode. At the lowest level, images are processed in gray scale. At the middle level, the image is transformed into the Hough domain. At the top level, global results, including missing information, is processed within a global context including domain heuristics as well as OCR. The three levels work closely together by passing information up and down between levels. We focus on the algorithm in the Hough transform domain and simply introduce the relationship between the levels of gray scale domain to the Hough transform domain and the Hough transform domain to the global domain. To avoid noise, an intelligent system could automatically choose the optimum transform zone and decode the barcode using the Hough transform. The traditional Hough transform takes too long, making it impractical for fast barcode recognition. We introduce a fast Hough transform algorithm that is specially designed for barcode decode. A key feature of this fast algorithm is control of the Hough transformation based on information from the low-level gray scale domain. For speed, initial scanning of the barcode waveform is done with the gray-scale image. Where there is high noise, specific regions of the Hough transform parameter space are utilized. In the Hough transform domain a special character level method is implemented in order to calculate key quality metrics for each charac

关键词： Hough transforms Image processing optical character recognition Evolutionary algorithms Detection and tracking algorithms Intelligence systems Artificial intelligence Binary data Control systems Edge detection

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Contrast Based Band Selection for Optimized Weathered Oil Detection in Hyperspectral Images

Contrast Based Band Selection for Optimized Weathered Oil De...

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conference on Remote Sensing of the Ocean, Sea Ice, Coastal Waters and Large Water Regions

作者： Levaux, Florian Bostater, Charles R. Neyt, Xavier Royal Mil Acad CISS Dept Fac Sci Appl Ave Renaissance 30 B-1000 Brussels Belgium Florida Inst Technol Coll Engn Melbourne FL USA

ISBN: (纸本)9780819492722

Hyperspectral imagery offers unique benefits for detection of land and water features due to the information contained in reflectance signatures such as the bi-directional reflectance distribution function or BRDF. The reflectance signature directly shows the relative absorption and backscattering features of targets. These features can be very useful in shoreline monitoring or surveillance applications, for example to detect weathered oil. In real-time detection applications, processing of hyperspectral data can be an important tool and Optimal band selection is thus important in real time applications in order to select the essential bands using the absorption and backscatter information. In the present paper, band selection is based upon the optimization of target detection using contrast algorithms. The common definition of the contrast (using only one band out of all possible combinations available within a hyperspectral image) is generalized in order to consider all the possible combinations of wavelength dependent contrasts using hyperspectral images. The inflection (defined here as an approximation of the second derivative) is also used in order to enhance the variations in the reflectance spectra as well as in the contrast spectrua in order to assist in optimal band selection. The results of the selection in term of target detection (false alarms and missed detection) are also compared with a previous method to perform feature detection, namely the matched filter. In this paper, imagery is acquired using a pushbroom hyperspectral sensor mounted at the bow of a small vessel. The sensor is mechanically rotated using an optical rotation stage. This opto-mechanical scanning system produces hyperspectral images with pixel sizes on the order of mm to cm scales, depending upon the distance between the sensor and the shoreline being monitored. The motion of the platform during the acquisition induces distortions in the collected HSI imagery. It is therefore necessa

关键词： Feature Detection and Discrimination Contrast algorithms Shoreline Monitoring and Surveillance Hyperspectral Imaging systems Hyperspectral Image Acquisition Platform Movement Correction Littoral Zone Environmental Surveillance optical Stage Mobile Platform Sensing Optimal Band Selection Matched Filter

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Post-processing of lattice dynamical data for large crystalline systems (disordered semiconductors)

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AIP conference Proceedings 2013年第1期1512卷 1319-1319页

作者： Andrei Postnikov LCP-A2MC Institute Jean Barriol University of Lorraine Metz France

In first-principes simulations of mixed semiconductors, the calculations ought to be done on large supercells, deprived of any symmetry due to random placement of atoms and their subsequent relaxation, even if underlying crystal structure is well defined. Calculation of force constants and subsequent diagonalization of the dynamical matrix produces large bulks of data in the form of very dense eigenvectors and long phonon eigenvectors. Different algorithms of projection help to extract meaningful information from these data, according to actual needs. Projections along with a given q-vector permit either (i) to enhance the genuinely zone-center phonon features, likely to be revealed in Raman or infrared spectra, or (ii) to reveal the traces of phonon dispersion as function of the q variation, in the situation where formally the translation symmetry is broken. Projections along with symmetry coordinates corresponding to different irreducible representations of the space group of the underlying perfect crystal help to approximatively attribute specific vibration patterns according to their symmetry properties, and hence to figure out experimental setup in which they can be observed. Similar techniques can be applied to the study of perfect crystals with complex structure, typically superlattices constructed from much simpler prototypes. The examples will be given from II-vi and III-V mixed (pseudobinary) semiconductors, from ternary and quaternary semiconductors used for photovoltaic applications, and others.

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A New Watermarking Sequence Generation Algorithm for Collision-free Digital Watermarking

A New Watermarking Sequence Generation Algorithm for Collisi...

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International conference on Intelligent information Hiding and Multimedia Signal processing (IIHMSP)

作者： V.A. Mitekin E.I. Timbay Image Processing Systems Institute of the RAS Samara Russia

A new algorithm for watermarking sequence generation is proposed, allowing collision-free robust watermarking using correlation-based watermark detector with known detection threshold. The proposed algorithm provides considerably large number of distinct watermarking sequences which makes it more robust to a brute-force watermark extraction attacks (compared to known algorithms for watermarking sequence generation). Also, proposed algorithm fulfills the set of application-specific requirements motivated by needs of watermarking scheme computational effectiveness, robustness etc.

关键词： Watermarking Robustness Hamming distance Signal processing algorithms Detectors Adaptive optics optical imaging

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Dynamics of vesicle suspension in shear flow between walls by digital holographic microscopy with a spatially reduced coherent source

Dynamics of vesicle suspension in shear flow between walls b...

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conference on optical Modelling and Design II

作者： Minetti, C. Podgorski, T. Coupier, G. Dubois, F. Univ Libre Bruxelles Serv Chim Phys EP CP 165 62 50 Av F Roosevelt B-1050 Brussels Belgium Univ Joseph Fourier CNRS Lab Spectrometrie Phys F-38402 St Martin Dheres France

ISBN: (纸本)9780819491213

Digital Holographic Microscopy (DHM) is a powerful tool that strongly increases the field of investigation of classical microscopy. It allows to be used as phase contrast microscopy with the additional information of the z position over a whole experimental volume by acquiring a single frame. The use of a spatially reduced coherent source strongly reduces the coherent noise. Vesicles are close lipid membranes enclosing a sugar-water solution. Those biomimetic deformable objects are good mechanical models of living cells such as Red Blood Cells. We investigate the dynamics of a vesicle suspension in shear flow between walls (with a gap of about 200 mu m). When vesicles are placed in a shear flow, they undergo a lift force that pushes them away from the wall until they reach the centre of the channel where the effects of both walls are compensated. On the other hand, hydrodynamical interactions between vesicles and segregation effects tend to push small vesicles away from the centre of the channel. The final distribution is thus a compromise between both effects that structures the distribution and has strong impact on rheology. DHM with reduced coherence and specific related algorithms (phase compensation, best focus plane determination, segmentation,.) provide a full description of each object in the experimental volume as a function of their size and shape. Results are provided and illustrate the quantification of the lift force and the hydrodynamical interactions (shear induced diffusion).

关键词： Partial coherence Image processing Cellular systems

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Real-time image processing of TOF range images using a single shot image capture algorithm

Real-time image processing of TOF range images using a singl...

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IEEE Instrumentation and Measurement Technology conference

作者： Stephan Hussmann Alexander Hermanski Department of Electrical Engineering and Information Technologies West Coast University of Applied Sciences Heide Germany Institute for Machine Vision Technology (Ma.Vi.Tec) West Coast University of Applied Sciences Heide Germany

During the last years, Time-of-Flight sensors achieved a significant impact onto research fields in machine vision. In comparison to other common 3D sensing devices they combine the advantages of active sensors providing accurate distance measurements and camera-based systems recording a 2D matrix at a high frame rate. This paper focuses on the currently implemented 4-phase-shift algorithm to calculate the range image in this type of sensors. A new approach is presented which increases the range calculation time by a factor of four. Experimental results show that the proposed algorithm is well suited for real-time processing of the range images of TOF cameras.

关键词： Cameras optical imaging optical sensors Logic gates optical modulation

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Cellular Wall Segmentation of A. Thaliana Epidermal Tissue in DIC Images

Cellular Wall Segmentation of A. Thaliana Epidermal Tissue i...

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Andean region International conference

作者： D. Ochoa J. D'Vylder W. Philips Facultad de Ingenieria en Electricidad y Computacion Escuela Superior Politecnica del Litoral Guayaquil Ecuador Department of Telecommunications and Information Processing IBBT- Image Processing and Interpretation Ghent University Ghent Belgium

ISBN: (纸本)9781467344272

In this work, we discuss the problems of automatic segmentation of Arabidopsis thaliana epidermal cell patterning in images captured using a Differential Interference Contrast (DIC) microscope. These images are difficult to analyze due to the non-linear nature of DIC optics. The border of objects appear as a combination of bright and dark shadows with variable thickens and contrast levels. Our segmentation approach exploits prior knowledge on the optical properties of A. thaliana cell walls. A set of matching filters and a scale space line detector are used to generate an enhanced image that shows a single response at the location of cellular walls. To reduce the uncertainty in low contrast cellular walls several images are captured at different orientations. After image fusion, we obtain a single image that can be segmented using well established algorithms. Experiments on a manually annotated DIC image data set demonstrated the effectiveness of the proposed scheme.

关键词： annotated effectiveness scheme

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Demo abstract: Simbeeotic: A simulation-emulation platform for large scale micro-aerial swarms

Demo abstract: Simbeeotic: A simulation-emulation platform f...

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International Symposium on information processing in Sensor Networks (IPSN)

作者： Jason Waterman Bryan Kate Karthik Dantu Matt Welsh Harvard University Cambridge MA USA Google Inc. Seattle WA USA

Micro-aerial vehicle (MAV) swarms are an emerging class of mobile sensing systems. Designing the next generation of such swarms requires the ability to rapidly test algorithms, sensors, and support infrastructure at scale. Simulation is useful in the early stages of such large-scale system design, when hardware is unavailable or deployment at scale is im-practical. To faithfully represent the problem domain, an MAV swarm simulator must be able to model all key aspects of the system: actuation, sensing, and communication. Further, it is important to be able to quickly test swarm behavior using different control algorithms in a varied set of environments, and with a variety of sensors. We demonstrate Simbeeotic, a simulation framework that is capable of modeling large-scale MAV swarms. Simbeeotic enables algorithm development and rapid prototyping through both simulation and hardware-in-the-loop experimentation. We demonstrate Simbeeotic running simulated applications and videos demonstrating hybrid experiments with simulated MAV s as well as helicopters flying in our test bed that show the power and versatility required to assist next generation swarm design.

关键词： Robot sensing systems optical sensors Vehicles Java visualization

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