We demonstrate the effective combination of multiphoton and photoacoustic (PA) imaging for the high-resolution stratigraphic analysis of multilayered art objects with emphasis on paintings. A novel convolution-based a...
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We demonstrate the effective combination of multiphoton and photoacoustic (PA) imaging for the high-resolution stratigraphic analysis of multilayered art objects with emphasis on paintings. A novel convolution-based algorithm is additionally applied for the precise discrimination of nonlinear signals, providing valuable information in regard to the thickness and composition of successive varnish and paint layers in the mock-up samples. On the other hand, PA contrast complements the extracted data by revealing well-hidden graphite underdrawings below the paint at high sensitivity levels. The final composite images are directly compared with cross-sectional brightfield observations, validating the capabilities of the bimodal diagnosis in terms of measurement accuracy and contrast specificity. The presented hybrid diagnostic approach has the potential to optimize delicate interventions in works of art such as the selective removal of aged materials, thus promoting a significantly improved restoration outcome. (c) 2019 Optical Society of America
We present a novel single-chip thermopile sensor array for mid-infrared room temperature imaging. The array is fabricated on a single complementary metal-oxide-semiconductor (CMOS) dielectric membrane, composed of sin...
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We present a novel single-chip thermopile sensor array for mid-infrared room temperature imaging. The array is fabricated on a single complementary metal-oxide-semiconductor (CMOS) dielectric membrane, composed of single-crystal silicon (Si) p(+) and n(+) elements, and standard CMOS tungsten metal layers for thermopile cold junction heatsinking, significantly reducing the chip size and simplifying its processing. We demonstrate a 16 x 16 pixel device with 34 V/W responsivity and enhanced optical absorption in the 8-14 mu m waveband, with a suitable performance for gesture recognition and people-counting applications. Our simple, low-cost sensor is an attractive on-chip array for a variety of applications in the mid-infrared spectral region. (C) 2019 Optical Society of America
Camera-phone-based medical devices (CPMDs) represent a major emerging platform for point-of-care diagnostic imaging of biological tissue. In order to evaluate degradation in texture reproduction due to visible light i...
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Camera-phone-based medical devices (CPMDs) represent a major emerging platform for point-of-care diagnostic imaging of biological tissue. In order to evaluate degradation in texture reproduction due to visible light imageprocessing performed by CPMDs, a method (MTFDL) involving the generation of a modulation transfer function (MTF) based on measurements of a 'dead leaves (DL)' target has been proposed. In this study, we have identified discrepancies in the quantification of noise based on gray patches of the DL target as compared to the textual region. To address this issue, we have proposed an approach (MTFDL-den) for accurate MTFDL calculation through the use of effectively denoised DL images. Furthermore, we demonstrate that our MTFDL-den approach provides superior robustness to simulated noise. These findings will help establish effective standardized test methods for realistic benchtop assessment of CPMD image quality. (C) 2019 Optical Society of America under the terms of the OSA Open Access Publishing Agreement
We demonstrate a broadband wavemeter by imaging the radiation from multiple interfering modes approaching cutoff in a tapered hollow waveguide (clad by omnidirectional Bragg mirrors). Dispersion of the cutoff point wa...
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We demonstrate a broadband wavemeter by imaging the radiation from multiple interfering modes approaching cutoff in a tapered hollow waveguide (clad by omnidirectional Bragg mirrors). Dispersion of the cutoff point was used to extract a coarse wavelength estimate, and subsequent computational analysis of the complex standing wave radiation pattern leading up to the cutoff point enabled a much finer estimate. This approach leverages the principles of speckle-based spectrometers but with added functionality provided by the spectral-spatial dispersion of the mode cutoff position. In proof-of-principle work, we verified a resolution < 10 pm over an operating range of nearly 100 nm in the near infrared using a tapered waveguide with a length < 1 mm. Significantly enhanced resolution should be possible through feasible refinements of the waveguides and peripheral components. (c) 2019 Optical Society of America under the terms of the OSA Open Access Publishing Agreement
In this paper, a study and evaluation of the combination of GPS/GNSS techniques and advanced image processing algorithms for distressed human detection, positioning and tracking, from a fully autonomous Unmanned Aeria...
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In this paper, a study and evaluation of the combination of GPS/GNSS techniques and advanced image processing algorithms for distressed human detection, positioning and tracking, from a fully autonomous Unmanned Aerial Vehicle (UAV)-based rescue support system, are presented. In particular, the issue of human detection both on terrestrial and marine environment under several illumination and background conditions, as the human silhouette in water differs significantly from a terrestrial one, is addressed. A robust approach, including an adaptive distressed human detection algorithm running every N input image frames combined with a much faster tracking algorithm, is proposed. Real time or near-real-time distressed human detection rates achieved, using a single, low cost day/night NIR camera mounted onboard a fully autonomous UAV for Search and Rescue (SAR) operations. Moreover, the generation of our own dataset, for the image processing algorithms training is also presented. Details about both hardware and software configuration as well as the assessment of the proposed approach performance are fully discussed. Last, a comparison of the proposed approach to other human detection methods used in the literature is presented.
This paper presents an analysis of code implementation performance for image processing algorithms. The test is made for image processing algorithms for robotic arms, but it is suitable for any type of image processin...
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ISBN:
(纸本)9781538651865
This paper presents an analysis of code implementation performance for image processing algorithms. The test is made for image processing algorithms for robotic arms, but it is suitable for any type of imageprocessing software. imageprocessing software can use quite big amount of resources, so this way it can be tested which platform, which operating system or which programming language is the most suitable for usage. The imageprocessing task is a color detection task with some line and circle overlays for robotic arm's guidance. The implementations were tested base on code line numbers, code size on disk, binary file size on disk, used memory during execution and used CPU during execution.
High-throughput crop phenotyping is harnessing the potential of genomic resources for the genetic improvement of crop production under changing climate conditions. As global food security is not yet assured, crop phen...
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High-throughput crop phenotyping is harnessing the potential of genomic resources for the genetic improvement of crop production under changing climate conditions. As global food security is not yet assured, crop phenotyping has received increased attention during the past decade. This spectral issue (SI) collects 30 papers reporting research on estimation of crop phenotyping traits using unmanned ground vehicle (UGV) and unmanned aerial vehicle (UAV) imagery. Such platforms were previously not widely available. The special issue includes papers presenting recent advances in the field, with 22 UAV-based papers and 12 UGV-based articles. The special issue covers 16 RGB sensor papers, 11 papers on multi-spectral imagery, and further 4 papers on hyperspectral and 3D data acquisition systems. A total of 13 plants' phenotyping traits, including morphological, structural, and biochemical traits are covered. Twenty different data processing and machine learning methods are presented. In this way, the special issue provides a good overview regarding potential applications of the platforms and sensors, to timely provide crop phenotyping traits in a cost-efficient and objective manner. With the fast development of sensors technology and image processing algorithms, we expect that the estimation of crop phenotyping traits supporting crop breeding scientists will gain even more attention in the future.
Obtaining an image of a scene is obvious and intuitive. The light refl ected from every object of the scene is collected with lenses and projected (imaged) onto an array of pixels (a sensor) that records the light int...
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Obtaining an image of a scene is obvious and intuitive. The light refl ected from every object of the scene is collected with lenses and projected (imaged) onto an array of pixels (a sensor) that records the light intensity. This basic operating principle lies behind cameras such as the ones in mobile phones.
This paper demonstrates a real-time user tracking and handover mechanism for indoor ultrahigh-speed beam-steered optical-wireless systems implementing a low-cost camera. This allows us to tackle LoS blocking by switch...
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ISBN:
(数字)9781943580712
ISBN:
(纸本)9781728167626
This paper demonstrates a real-time user tracking and handover mechanism for indoor ultrahigh-speed beam-steered optical-wireless systems implementing a low-cost camera. This allows us to tackle LoS blocking by switching to a secondary beam-steering device automatically.
We present upstream signaling and localization for an indoor beam-steered OWC system using vision-based technology. We demonstrate a 1.2kbps upstream signaling and localization system which enables to identify a large...
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ISBN:
(数字)9781943580712
ISBN:
(纸本)9781728167626
We present upstream signaling and localization for an indoor beam-steered OWC system using vision-based technology. We demonstrate a 1.2kbps upstream signaling and localization system which enables to identify a large number of users with
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