- 标题
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A Hyperspectral Imaging Instrumentation Architecture Based on Accessible Optical Disc Technology and Frequency-Domain Analyses
摘要： Hyperspectral imaging (HSI) is an emergent instrumentation technology with great potential in many applications, due to its ability to measure important spectral features. However, the widespread adoption of HSI requires the development of accessible (i.e., inexpensive and uncomplicated) HSI instrumentation architectures. In this paper, we present, design, develop, and evaluate an accessible HSI instrumentation architecture, with snapshot operation, based on the integration of readily available components and frequency multiplexing with Fourier analyses. In the experimental work, an incident image beam is divided into spatial image channels, each with an assigned dynamic binary code via a dynamic coded aperture. This dynamic coded aperture is constructed from repurposed diffractive optical disc technologies and is patterned with strategic opaque and transparent regions. When it is rotated by a motor, dynamic binary codes are used, along with Fourier analyses, to identify the diffraction of each spatial image channel. The spatially overlapped spectra from the diffraction are directed onto a charge-coupled device sensor, and each spatial image channel is distinguished through Fourier analyses. The resulting Fourier amplitude spectra are transformed into corresponding functions of wavelength, and this transformation is based on the experimental instrumentation geometry. The performance of the HSI instrumentation architecture is evaluated using a comparison with data from a commercial spectrometer. The presented HSI instrumentation architecture can be adapted for 2-D operation. Ultimately, the presented HSI instrumentation architecture can benefit regions of the world that have limited financial resources and a need for accessible HSI technologies.
关键词： Electromagnetic devices,optical diffraction,hyperspectral sensors,multispectral imaging
更新于2025-09-23 15:23:52
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Multispectral imaging: Monitoring vulnerable people
摘要： This paper describes the development of a new healthcare monitoring system for vulnerable people which uses a visible image sensor and passive infrared sensors, in an unconventional manner, to monitor daily living activities. It based on a novel method, using chromatic methodology, to process spatially and temporally the incoming multispectral data from the visible and infrared parts of the spectrum, to overcome the impact of noisy environments, illumination changes and a dynamic background. An efficient chromatic descriptor is suggested to improve activity recognition of vulnerable people. The new monitoring system is robust to distortions associated with healthcare systems and its descriptor has an improved quality of description. System performance was evaluated using a series of experimental data, the results showing the efficacy of using both spatial and temporal domains of multispectral data to deal with events that disturb monitoring systems. The chromatic descriptor achieved a better performance in comparison to traditional methods when describing daily living activities.
关键词： Raspberry Pi,Laser image segmentation,Healthcare monitoring,Multispectral imaging,Microsoft Kinect
更新于2025-09-23 15:22:29
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Multispectral imaging of mineral samples by infrared quantum dot focal plane array sensors
摘要： Infrared (IR) spectral imaging is a powerful tool for component analysis and identification in the geological field. In this report, we originally use quantum dot infrared photodetector (QDIP) focal plane arrays (FPAs) with different peak-responsivity wavelengths to analyze the mineral composition of rock samples by IR spectral imaging and show the QDIP’s potential as a solution for some geological problems. After clarifying fundamental characteristics such as the blackbody responsivity, current noise density, and spectral responsivity of QDIPs, we present qualitative and quantitative analyses of mineral samples including conglomerate, sandstone, marble, and dolomite. In the qualitative analysis, we distinguish two different compositions in each rock. In the quantitative analysis, we measure the emittance of dolomite and show the emittance errors. Finally, we discuss which experimental factor determines the quantitative precision most dominantly.
关键词： Quantum dot,Focal plane array,Mineral,Multispectral imaging
更新于2025-09-23 15:21:01
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Spectral Adaptation Transform for Multispectral Constancy
摘要： The spectral reflectance of an object surface provides valuable information of its characteristics. Reflectance reconstruction from multispectral image data is typically based on certain assumptions. One of the common assumptions is that the same illumination is used for system calibration and image acquisition. The authors propose the concept of multispectral constancy which transforms the captured sensor data into an illuminant-independent representation, analogously to the concept of computational color constancy. They propose to transform the multispectral image data to a canonical representation through spectral adaptation transform (SAT). The performance of such a transform is tested on measured reflectance images. The authors also investigate the robustness of the transform to the inaccuracy of illuminant estimation in natural scenes. Results of reflectance reconstruction show that the proposed SAT is efficient and is robust to error in illuminant estimation.
关键词： multispectral imaging,multispectral constancy,spectral reconstruction,spectral adaptation transform,illuminant estimation
更新于2025-09-19 17:15:36
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The Encyclopedia of Archaeological Sciences || Multispectral and Hyperspectral Imaging
摘要： In the field of archaeology (and heritage in general), many documentation and examination methods are based on imaging techniques that characterize and depict artifacts in a nondestructive and mechanically noninvasive way. Multi- and hyperspectral imaging (together denoted spectral imaging) are two possible forms of such noninvasive imaging. Both are based on the detection of reflected or emitted optical electromagnetic radiation, the latter being defined as electromagnetic waves with wavelengths between 10 nm (0.01 μm) and 1 mm (1,000 μm). This detection can be better understood when considering that optical digital imaging usually generates a signal that is the outcome of a three-variable process: electromagnetic radiation of a radiation source falls onto the object; this radiation is partly absorbed, transmitted, and reflected by the object, with the interaction being wavelength dependent; and the imager detects and digitizes the incoming radiance in specific spectral regions. Spectral imaging extends traditional trichromatic digital camera approaches by capturing data in at least four different spectral bands, with hyperspectral imaging featuring higher spectral resolution and more contiguous spectra. Applications include archaeological prospection, color-accurate documentation, material identification, and enhancing the reading of old documents. Drawbacks involve data quantity, noise proneness, and reliance on specialized hardware and software, with future research focusing on active systems like multi-wavelength laser scanners.
关键词： multispectral imaging,archaeology,hyperspectral imaging,data cube,spectral signature,future research,drawbacks,electromagnetic radiation,noninvasive imaging,applications,spectral imaging,heritage
更新于2025-09-19 17:15:36
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Rapid Measurement of Soybean Seed Viability Using Kernel-Based Multispectral Image Analysis
摘要： Viability is an important quality factor influencing seed germination and crop yield. Current seed-viability testing methods rely on conventional manual inspections, which use destructive, labor-intensive and time-consuming measurements. The aim of this study is to distinguish between viable and nonviable soybean seeds, using a near-infrared (NIR) hyperspectral imaging (HSI) technique in a rapid and nondestructive manner. The data extracted from the NIR–HSI of viable and nonviable soybean seeds were analyzed using a partial least-squares discrimination analysis (PLS-DA) technique for classifying the viable and nonviable soybean seeds. Variable importance in projection (VIP) was used as a waveband selection method to develop a multispectral imaging model. Initially, the spectral profile of each pixel in the soybean seed images was subjected to PLS-DA analysis, which yielded a reasonable classification accuracy; however, the pixel-based classification method was not successful for high accuracy detection for nonviable seeds. Another viability detection method was then investigated: a kernel image threshold method with an optimum-detection-rate strategy. The kernel-based classification of seeds showed over 95% accuracy even when using only seven optimal wavebands selected through VIP. The results show that the proposed multispectral NIR imaging method is an effective and accurate nondestructive technique for the discrimination of soybean seed viability.
关键词： kernel-based classification,seed viability,multispectral imaging,variable importance in projection,near-infrared
更新于2025-09-19 17:15:36
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Fabrication of a CMOS-based Imaging Chip with Monolithically Integrated RGB and NIR Filters
摘要： Recent developments in multispectral cameras have demonstrated how compact and low-cost spectral sensors can be made by monolithically integrating filters on top of commercially available image sensors. In this paper, the fabrication of a RGB + NIR variation to such a single-chip imaging system is described, including the integration of a metallic shield to minimize crosstalk, and two interference filters: a NIR blocking filter, and a NIR bandpass filter. This is then combined with standard polymer based RGB colour filters. Fabrication of this chip is done in imec's 200 mm cleanroom using standard CMOS technology, except for the addition of RGB colour filters and microlenses, which is outsourced.
关键词： multispectral imaging,RGB,NIR,CMOS image sensor,monolithic integration,optical filters
更新于2025-09-19 17:15:36
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[Methods in Molecular Biology] Immune Checkpoint Blockade Volume 1913 (Methods and Protocols) || Multispectral Fluorescence Imaging Allows for Distinctive Topographic Assessment and Subclassification of Tumor-Infiltrating and Surrounding Immune Cells
摘要： Histomorphology has significantly changed over the last decades due to technological achievements in immunohistochemistry (IHC) for the visualization of specific proteins and in molecular pathology, particularly in the field of in situ hybridization of small oligonucleotides and amplification of DNA and RNA amplicons. With an increased availability of suitable methods, the demands regarding the observer of histomorphological slides were the supply of complex quantitative data as well as more information about protein expression and cell-cell interactions in tissue sections. Advances in fluorescence-based multiplexed IHC techniques, such as multispectral imaging (MSI), allow the quantification of multiple proteins at the same tissue section. In histopathology, it is a well-known technique for over a decade yet harboring serious problems concerning quantitative preciseness and tissue autofluorescence of multicolor staining when using formalin-fixed, paraffin-embedded (FFPE) tissue specimen. In recent years, milestones in tissue preparation, fluorescent dyes, hardware imaging, and software analysis were achieved including automated tissue segmentation (e.g., tumor vs. stroma) as well as in cellular and subcellular multiparameter analysis. This chapter covers the role that MSI plays in anatomic pathology for the analysis of FFPE tissue sections, discusses the technical aspects of MSI, and provides a review of its application in the characterization of immune cell infiltrates and beyond regarding its prognostic and predictive value and its use for guidance of clinical decisions for immunotherapeutic strategies.
关键词： Phenotyping,Immune cells,Fluorescence microscopy,Multispectral imaging
更新于2025-09-19 17:15:36
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Multispectral incoherent holography based on measurement of differential wavefront curvature
摘要： We propose a technique of multispectral incoherent holography. The differential wavefront curvature is measured, and the principle of Fourier transform spectrometry is applied to provide a set of spectral components of three-dimensional images and continuous spectra for spatially incoherent, polychromatic objects. This paper presents the mathematical formulation of the principle and the experimental results. Three-dimensional imaging properties are investigated based on an analytical impulse response function. The experimental and theoretical results agree well.
关键词： Impulse response function,Multispectral imaging,Depth resolution,3D imaging property,Spectroscopy,Incoherent holography
更新于2025-09-19 17:13:59
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Electrically tunable multicolored filter using birefringent plasmonic resonators and liquid crystals
摘要： Dynamic tuning of color filters finds numerous applications including displays or image sensors. Plasmonic resonators are sub–wavelength nanostructures which can tailor the phase, polarization and amplitude of the optical field but they are limited in color vibrancy when used as filters. In this work, birefringence–induced colors of plasmonic resonators and a fast switching thin liquid crystal cell are combined in a multicolored electrically tunable filter. With this mechanism, the color gamut of the plasmonic surface and the liquid crystal cell is mutually enhanced in order to generate all primary additive and subtractive colors with high saturation as well as different tones of white. A single filter is able to cover more than 70% of the color gamut of standard RGB filters by applying a voltage ranging between 2V and 6.5V. This spectral selectivity is added in transmission without any loss in the image resolution. The presented approach is foreseen to be implemented in a variety of devices including miniature sensors or smart-phone cameras to enhance the color information, ultra–flat multispectral imagers, wearable or head–worn displays as well as high resolution display panels.
关键词： liquid crystals,color display,nanoimprint lithography,multispectral imaging,Plasmonic colors,tunable filters
更新于2025-09-12 10:27:22