The CMY colour camera is different from the RGB counterpart where the subtractive colours cyan, magenta and yellow are used. The CMY camera performs better than an RGB camera in low light conditions. However, conventi...
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The CMY colour camera is different from the RGB counterpart where the subtractive colours cyan, magenta and yellow are used. The CMY camera performs better than an RGB camera in low light conditions. However, conventional CMY colour filter technology made of pigments and dyes are limited in performance for next generation image sensors with submicron pixel sizes. This is because the conventional CMY filters cannot be fabricated in nanoscale as they use their absorption properties to subtract colours. This paper presents a CMOS compatible nanoscale thick CMY colour mosaic made of Al-TiO2-Al nanorods forming a total number of 0.82 million colour filter pixels with each filter pixel size of 4.4 mu m arranged in a CMYM pattern. The colour mosaic was then integrated on a MT9P031 image sensor to make a CMY camera and colour imaging is demonstrated using a 12 colour Macbeth chart. The developed technology will have applications in astronomy, low exposure time imaging in biology, and photography.
Cell culture experiments are usually performed as in vitro studies based on 2D seeding and characterization (light microscopy). With respect to the in vivo situation, however, 2D studies are often inappropriate due to...
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Cell culture experiments are usually performed as in vitro studies based on 2D seeding and characterization (light microscopy). With respect to the in vivo situation, however, 2D studies are often inappropriate due to the 3D character of living tissue in nature. Textiles with their versatile 3D structures are chosen as suitable scaffolds in tissue engineering for 3D in vitro studies. Micro-computed tomography using X-rays (muCT) belongs to the most promising techniques for isotropic, noninvasive 3D characterization. Using synchrotron radiation (SRmuCT) the spatial resolution can be extended to the sub-micrometer range well below cell size. muCT does not need vacuum conditions making experiments in the hydrated state possible, as we show by data from SRmuCT acquired at second and third-generation synchrotron sources. We seeded human foreskin fibroblasts on polymer multifilament yarns. These composites, embedded in a hydrogel or fluid, are held in thin-walled glass capillaries. Since the composites consist of light elements, the cells have to be labeled for visualization by the use of highly absorptive agents, osmium and gold. In order to hold the label concentration as low as possible, we present a way to choose the photon energy for which the minimum concentration is reached. Differences in threshold selection for second- and third-generation synchrotron sources are pointed out, revealing the advantages of both types with respect to quantitative analysis. The study is based on appropriate staining methods and protocols developed in our laboratory. With the results we demonstrate that SRmuCT yields images similar to established electron and light microscopy but uncovers also the microstructure in 3D space. (C) 2002 Published by Elsevier Science B.V.
Speckle appearing in synthetic-aperture-radar images degrades the information contained in these images. Speckle noise can be suppressed by adapted local processing techniques, permitting the definition of statistical...
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Speckle appearing in synthetic-aperture-radar images degrades the information contained in these images. Speckle noise can be suppressed by adapted local processing techniques, permitting the definition of statistical parameters inside a small window centered on each pixel of the image. Two processingalgorithms are examined; the first one uses the intensity as a variable, and the second one works on a homomorphic transformation of the image intensity. A statistical model for speckle noise that takes into account correlation in multilook imagery has been used to develop these processingalgorithms. Several experimental results of processed Seasat-A syntheticaperture-radar images are discussed.
A method for simulating sea surface images obtained by forward-looking infrared (FLIR) sensors in the 8–12-μm band, which can be readily implemented on a computer, has been developed. The model consists of a bottom-...
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A method for simulating sea surface images obtained by forward-looking infrared (FLIR) sensors in the 8–12-μm band, which can be readily implemented on a computer, has been developed. The model consists of a bottom-up process based on oceanographic models of sea waves and radiometric properties of sky and sea. The clutter which is generated by sea surface roughness and nonuniformity of sky radiation has been found to be a Gaussian homogeneous random process, under reasonable assumptions. The variance of this process as well as its spatial correlation has been investigated. The value of the method as a synthetic image generator and the application of the results to FLIR imageprocessing are discussed.
Laser speckle contrast imaging (LSCI) can be used to observe dynamic changes in the tissue microcirculation in vivo according to the dynamic interaction between red blood cells and coherent light. In this study, a dua...
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Laser speckle contrast imaging (LSCI) can be used to observe dynamic changes in the tissue microcirculation in vivo according to the dynamic interaction between red blood cells and coherent light. In this study, a dual-wavelength LSCI system based on a microscope was developed for in vivo observation of the microvascular pattern and measurement of the blood flow change in the animal model. Additionally, based on the dual-wavelength setup, including 635 and 855 nm wavelengths, the oxygenation of biological tissue was evaluated. Finally, the developed LSCI microscope was implemented for the studies of tissue microcirculation. The results indicate that the developed LSCI microscope could be a potential tool for in vivo observation of the tissue microcirculation and quantitative evaluation of hemodynamics in animal experiments. (C) 2020 Optical Society of America under the terms of the OSA Open Access Publishing Agreement
Natural background was recorded in the 8–12-μmband using an airborne IR camera. The results were analyzed, and the statisticaland spatial features of the radiance in this band were found. The statisticaldistribution...
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Natural background was recorded in the 8–12-μmband using an airborne IR camera. The results were analyzed, and the statisticaland spatial features of the radiance in this band were found. The statisticaldistribution approaches the normal distribution inside the two standarddeviation regions but deviates slightly outside. The spatial autocorrelationfunction fits to a high degree a 2-D exponent.
A very powerful space-variant imageprocessing technique such as median filtering is performed using the polarization-encoded optical shadow casting (POSC) system. The POSC system is used to process two different nois...
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A very powerful space-variant imageprocessing technique such as median filtering is performed using the polarization-encoded optical shadow casting (POSC) system. The POSC system is used to process two different noisy images. Two different POSC architectures and input encodings are identified and compared.
Issues associated with the radar detection of military targets that are concealed or camouflaged by forest clutter are described. The specific sensor platform can be categorized as an ultrawideband (UWB) foliage penet...
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Issues associated with the radar detection of military targets that are concealed or camouflaged by forest clutter are described. The specific sensor platform can be categorized as an ultrawideband (UWB) foliage penetration (FOPEN) synthetic aperture radar (SAR). The discussion illustrates the fact that many contemporary approaches to FOPEN target detection Are computationally intensive and/or require the implementation of elaborate training procedure's. Alternative approaches, based the application of a set of simple rank-order filters (alternately known as order statistical or L filters), are presented. Initial results indicate impressive performance levels (in terms of probability of detection as a function of false-alarm rate) with respect to baseline constant false-alarm rate computations. A number of avenues for future investigations are cited.
An asynchronous method of implementing the digital multiplication by analog convolution algorithm is presented. The mixed binary output is formed in one switching time regardless of the number of bits in the word. Nov...
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An asynchronous method of implementing the digital multiplication by analog convolution algorithm is presented. The mixed binary output is formed in one switching time regardless of the number of bits in the word. Novel circuitry that logarithmically reduces the number of shift and add levels is shown.
Convenient methods based on suitably designed finite-impulse-response (FIR) or infinite-impulse-response (IIR) filters were proposed recently for identifying edges in machine vision. We show that under normal image co...
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Convenient methods based on suitably designed finite-impulse-response (FIR) or infinite-impulse-response (IIR) filters were proposed recently for identifying edges in machine vision. We show that under normal image conditions (which are satisfied virtually always in practical indoor scenes) a FIR filter with powers-of-2 coefficients is able to provide results that are equivalent to those of an 8-bit FIR filter or a 16-bit HIR filter. This permits a significant simplification in the implementation design for edge detection. Results for common two-dimensional images processed with the simplified algorithm are presented, and a comparison is made with results obtained from so-called optimal nonapproximated operators.
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