修车大队一品楼qm论坛51一品茶楼论坛,栖凤楼品茶全国楼凤app软件 ,栖凤阁全国论坛入口,广州百花丛bhc论坛杭州百花坊妃子阁

oe1(光电查) - 科学论文

过滤筛选

出版时间
  • 2018
研究主题
  • LED stage lighting
  • CRI
  • RGBW four-color mixing model
  • the blackbody locus fitting
应用领域
  • Optoelectronic Information Science and Engineering
机构单位
  • Communication University of China
416 条数据
?? 中文（中国） ▾

  • Photometric and astrometric study of open cluster FSR 814 (Koposov 36) using SDSS/2MASS/PPMXL/Gaia DR2

    摘要： We present multi photometric and astrometric study of open cluster FSR 814 (Koposov 36) selected from the FSR catalog in different bands of Sloan Digital Sky Survey (SDSS), 2MASS, PPMXL and Gaia DR2. This study contains new results with a very high accuracy for the first time and generates the multi decontaminated color-magnitude diagrams to estimate the main astrophysical properties (such as: diameter, age, distance, reddening, geometrical projected distances, luminosity and mass functions) of FSR 814. Our results have been compared with other literatures.

    关键词： Color-Magnitude Diagram (CMD),Open clusters and associations: individual (FSR 814),Astrometry

    更新于2025-09-23 15:23:52

  • [IEEE 2018 Ubiquitous Positioning, Indoor Navigation and Location-Based Services (UPINLBS) - Wuhan (2018.3.22-2018.3.23)] 2018 Ubiquitous Positioning, Indoor Navigation and Location-Based Services (UPINLBS) - Image Processing Based Indoor Localization System for Assisting Visually Impaired People

    摘要： Indoor localization or indoor positioning system is a known as a process of detecting position of any object or people inside a building or room by different sensory data collected from different devices using different techniques such as radio waves, magnetic fields, acoustic signals or other procedures. However, lacking of a standard localization system is still a very big concern. Solution of this issue can be very beneficial for people in many cases but it can be especially very beneficial for the visually impaired people. In this paper, an image processing based indoor localization system has been developed using OpenCV and Python by following color detection technique to detect position of the user with maximum accuracy and then location of user is determined by analyzing that location matrix. Location accuracy depends on the size of the matrix and successful identification of target color. Firebase real time database was added to the system which made real time operations between server and the user end device easier. To justify the proposed model, successful experiments were conducted in indoor environments as well and correct result was achieved each time by detecting accurate locations. This will be very advantageous to observe the fully or partially sightless people and guide them towards their destination and also to inspect them for their security purpose.

    关键词： Color Segmentation,Indoor localization,Image Processing,Indoor positioning system,Wireless communication,Connected object detection

    更新于2025-09-23 15:23:52

  • Piezoluminescent devices by designing array structures

    摘要： Mechanoluminescence has attracted increasing attentions because it can convert the kinetic energy during human daily motions into light to be used in sensors and displays. However, its practical applications are still hindered by the weak brightness and limited color while under large forces. Herein, we developed novel piezoluminescent devices (PLDs) which could effectively emit visible light under low pressing forces through the stress-concentration and enhancing deformation on the basis of carefully-designed array structures. The emitting colors were also tunable by using bilayer luminescent film under different pressures. This work not only provides a new strategy to effectively harvest mechanical energy into light, but also presents a scalable, low-cost and color-tunable PLD which shows great potentials in various applications such as luminescent floors, shoes and stress-activated displays.

    关键词： mechanoluminescence,color-tunable,piezoluminescent device,array structure

    更新于2025-09-23 15:23:52

  • Color-center formation and thermal recovery in X-ray and electron-irradiated magnesium aluminate spinel

    摘要： We have studied the formation of color centers in magnesium aluminate spinel (MgAl2O4) by X-ray and electron irradiations near room temperature (RT). For this purpose, Cu Kα radiation and three electron energies (1.0, 1.4, and 2.5 MeV) were used for variable fluences (up to 4.2 × 10^18 cm^?2). Off-line UV-visible absorption spectra were recorded at RT as well as at low temperature down to 27 K after electron irradiation. The dependence of the production rate of F centers (oxygen vacancies) on the electron energy yields a threshold displacement energy of 190 ± 10 eV for oxygen atoms at RT, which is much higher than the determinations by molecular-dynamics simulations. Such a discrepancy is discussed on the basis of available migration data of point defects in spinel. Equipartition of F0 and F+ centers, i.e., the neutral (VO^x) and singly ionized (VO^.) oxygen vacancies, is reached for high electron fluences. Moreover, the evolution of the width of color-center absorption bands versus temperature is interpreted with the classical theory for F centers (neutral halogen vacancies) in alkali halides. The Stokes shifts are deduced from the temperature dependence of the absorption bandwidths of color centers like for alkali halides and alkaline-earth oxides. Finally, isothermal annealing data for long annealing time show a non-zero asymptotic behavior for both F0 and F+ centers. This uncommon behavior is interpreted by charge exchange processes leading to an equilibrium state between those two color centers.

    关键词： thermal recovery,X-ray irradiation,color centers,threshold displacement energy,F centers,electron irradiation,absorption spectroscopy,magnesium aluminate spinel

    更新于2025-09-23 15:23:52

  • Modeling apparent camouflage-pattern color using segment-weighted spectra

    摘要： Camouflage patterns for military applications, typically upon base materials such as dyed fabrics, consist of highly detailed camouflage patternings that are characterized by combined refectance spectra. The complexity of these camouflage patterns establishes a need for modeling camouflage-pattern reflectance for pattern evaluation as a function of distance. A metric for pattern evaluation is the apparent-camouflage-pattern reflectance spectrum, which is the total reflectance due to all contributions from component segments, within a wavelength range of interest, for light reflected from sufficiently large fabric samples ( ≥ 1m2), as a function of stand-off distance. This follows in that camouflage patterns tend to lose contributions to the total reflectance from component segments, having less coverage, with increasing standoff distance. Eventually, with increasing distance, reflectance of pattern segments having more coverage combine to produce the “apparent spectrum” of the camouflage pattern at far field. The physical characteristics of camouflage-pattern reflectance spectra are based on far-field and diffuse scattering properties of electromagnetic waves. Accordingly, a modeling approach can be developed to simulate camouflage-pattern spectra using diffuse-reflectance theory, which is based on decomposition of camouflage-pattern reflectance with respect to component segments of camouflage patterns. This paper presents a modeling approach and prototype simulations of camouflage-pattern reflectance within the visible range of wavelengths, which are relevant for evaluating camouflage fabrics with respect to realistic field conditions. A significant aspect of this modeling approach is that it can be extended for simulation of a wide range of factors influencing detection of camouflaged targets.

    关键词： apparent color,di?use re?ectance,Camou?age patterns,camou?age modeling

    更新于2025-09-23 15:23:52

  • [IEEE 2018 IEEE Southwest Symposium on Image Analysis and Interpretation (SSIAI) - Las Vegas, NV (2018.4.8-2018.4.10)] 2018 IEEE Southwest Symposium on Image Analysis and Interpretation (SSIAI) - REVERSIBLE COLOR-TO-GRAY MAPPING WITH RESISTANCE TO JPEG ENCODING

    摘要： The use of a reversible color-to-gray algorithm is an effective technique in practical applications, in terms of running cost, data quantity, security, etc. Most conventional image processing approaches cannot apply image encoding to color-embedded gray images. In this study, we propose a reversible color-to-gray method with resistance to JPEG encoding. To embed color information, the discrete cosine transformation (DCT) is employed, with good affinity to JPEG encoding. In the proposed method, first an input color image is converted to the YCbCr color space, and the DCT coefficients of the Cb and Cr components are embedded into the DCT coefficients of the Y component. Then using the JPEG quantization table, an appropriate embedding position is determined. Experiments were performed on standard color images, and the color recovery error after JPEG coding was compared and verified with conventional methods using PSNR and CIEDE2000.

    关键词： information embedding,image coding,color recovery,Color-to-gray mapping

    更新于2025-09-23 15:22:29

  • Image defogging approach based on incident light frequency

    摘要： Aiming at solving the problem of color distortion existing in the dark original pruning algorithm, an improved transmittance computation approach separated for each color channel is proposed. Firstly, the influence of the incident light frequency on the transmittance of each color channel is analyzed based on Beer-Lambert law. Meanwhile, the proportional relationship among the transmittance of each channel is deduced. Secondly, the image is resumed to improve the operation efficiency. After that, the image is pretreated to get the refined transmittance. Finally, the transmittance of all the color channels is obtained through the proportional relationship. And the corresponding transmittance is used to recover the image on each channel. Thus, the image defogging is realized. We evaluate the proposed algorithm qualitatively and quantitatively. From the subjective results, the proposed algorithm has better visual effect than that of the other algorithms, and our method has more details compared to the other two methods. While from the objective results, the proposed approach can achieve natural image color without high saturation, and reduce the running time by 4 to 10 times compared with several state-of-art algorithms. The proposed algorithm can obtain a higher color fidelity and a better image color in terms of e, r and H. The proposed method is obviously superior to those of the others in terms of no-reference quality evaluator in spatial domain and has the highest average PSNR value.

    关键词： Incident light frequency,Image defogging,Transmittance,Dark primary color prior,Color distortion

    更新于2025-09-23 15:22:29

  • Novel color standards for digital color analysis of optochemical sensor arrays

    摘要： The indicator-based polymeric color standards for color referencing in digital color analysis (DCA) of optical chemical sensors (optodes) are proposed. In the novel standards, the colors referring to the actual absorption bands of the protonated and deprotonated forms of the indicator are mixed in constant proportions. The standards are based on the lipophilic pH-indicators: ETH5350 and ETH2439, commonly used in optodes, and the lipophilic electrolyte TBATBB. The dependence of the standard color on the TBATBB concentration in the optode is established and found to be linear. The standard colors remain unchanged upon varying the solution pH and the nature and the concentration of the electrolyte. Calibration curves of the indicator pH-optodes obtained in horse serum and referenced to the developed standards demonstrate lower error to span ratio, broader span and higher sensitivity as compared to the same data processed with the conventional gray standard. The colorimetric signal of the pH-optodes array measured in serum sample and referenced to the developed standards allowed accurate determination of the sample pH thus demonstrating practical prospects of the proposed color standards.

    关键词： color standards,digital color analysis,optical chemical sensors,polymeric optodes

    更新于2025-09-23 15:22:29

  • [IEEE 2018 25th IEEE International Conference on Image Processing (ICIP) - Athens, Greece (2018.10.7-2018.10.10)] 2018 25th IEEE International Conference on Image Processing (ICIP) - Perception Preserving Decolorization

    摘要： Decolorization is a basic tool to transform a color image into a grayscale image, which is used in digital printing, stylized black-and-white photography, and in many single-channel image processing applications. While recent researches focus on retaining as much as possible meaningful visual features and color contrast. In this paper, we explore how to use deep neural networks for decolorization, and propose an optimization approach aiming at perception preserving. The system uses deep representations to extract content information based on human visual perception, and automatically selects suitable grayscale for decolorization. The evaluation experiments show the effectiveness of the proposed method.

    关键词： Color-to-gray conversion,perception preserving,deep neural networks

    更新于2025-09-23 15:22:29

  • [IEEE 2018 OCEANS - MTS/IEEE Kobe Techno-Ocean (OTO) - Kobe, Japan (2018.5.28-2018.5.31)] 2018 OCEANS - MTS/IEEE Kobe Techno-Oceans (OTO) - Multi-Scale Gradient Domain Underwater Image Enhancement

    摘要： Underwater images often suffer from low visibility, due to the attenuation and scattering of the propagated light, which are caused by the dense and non-uniform medium. Based on the observation that degradation of underwater images occurs both in contrast and color, this paper aims at compensating the contrast and color saturation of the image respectively. To achieve this, we first white balance the degraded image to remove the color casts while producing a natural appearance of the underwater image. Then propose a multi-scale gradient domain contrast enhancement strategy to increase the visibility, and compensate the attenuation of color saturation according to the estimated transmission. Both qualitative and quantitative results demonstrate the effectiveness of the proposed method. Our method yields accurate results with significantly enhanced contrast and superior color, even better than other state-of-the-art methods.

    关键词： Underwater image,Gradient Domain,Contrast enhancement,Edge-preserving image decomposition,Color correction

    更新于2025-09-23 15:22:29