- 标题
- 摘要
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- 实验方案
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Spectral Optimization to Minimize Light Absorbed by Artwork
摘要： Light is needed to appreciate artwork, but visible radiation causes damage by photochemical action. Photons trigger photochemical action only when they are absorbed by the object. Damage to sensitive materials can be reduced by optimizing the spectrum of a light source to the reflectance factor of a museum artifact. Absorption minimization approaches can be utilized to quantify and optimize typically conflicting parameters, such as damage due to light absorption, color quality of artwork, and energy consumption. In this project, seven narrowband light emitting diodes (LEDs) are optimized using a multi-objective genetic algorithm to reduce light absorption and energy consumption, while maintaining the color appearance of five paints (blue, green, yellow, orange, red). Results indicate that optimized test spectra can reduce light absorption between 18% and 48%, without causing perceptible color or hue shifts in the paintings. Parallel to absorption, energy consumption is almost halved for all of the paints (between 42% and 48%). Optimizing the light source spectrum can aid in conservation of art collections in museums by reducing damage caused by optical radiation while preserving color fidelity.
关键词： color perception,LED sources and systems,Art conservation,museum lighting,color rendition
更新于2025-09-23 15:23:52
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[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
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Illumination discrimination in the absence of a fixed surface-reflectance layout
摘要： Previous studies have shown that humans can discriminate spectral changes in illumination and that this sensitivity depends both on the chromatic direction of the illumination change and on the ensemble of surfaces in the scene. These studies, however, always used stimulus scenes with a fixed surface-reflectance layout. Here we compared illumination discrimination for scenes in which the surface reflectance layout remains fixed (fixed-surfaces condition) to those in which surface reflectances were shuffled randomly across scenes, but with the mean scene reflectance held approximately constant (shuffled-surfaces condition). Illumination discrimination thresholds in the fixed-surfaces condition were commensurate with previous reports. Thresholds in the shuffled-surfaces condition, however, were considerably elevated. Nonetheless, performance in the shuffled-surfaces condition exceeded that attainable through random guessing. Analysis of eye fixations revealed that in the fixed-surfaces condition, low illumination discrimination thresholds (across observers) were predicted by low overall fixation spread and high consistency of fixation location and fixated surface reflectances across trial intervals. Performance in the shuffled-surfaces condition was not systematically related to any of the eye-fixation characteristics we examined for that condition, but was correlated with performance in the fixed-surfaces condition.
关键词： illumination perception,color vision,eye fixations,chromatic illumination discrimination
更新于2025-09-23 15:22:29
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Color Constancy in Two-Dimensional and Three-Dimensional Scenes: Effects of Viewing Methods and Surface Texture
摘要： There has been debate about how and why color constancy may be better in three-dimensional (3-D) scenes than in two-dimensional (2-D) scenes. Although some studies have shown better color constancy for 3-D conditions, the role of specific cues remains unclear. In this study, we compared color constancy for a 3-D miniature room (a real scene consisting of actual objects) and 2-D still images of that room presented on a monitor using three viewing methods: binocular viewing, monocular viewing, and head movement. We found that color constancy was better for the 3-D room; however, color constancy for the 2-D image improved when the viewing method caused the scene to be perceived more like a 3-D scene. Separate measurements of the perceptual 3-D effect of each viewing method also supported these results. An additional experiment comparing a miniature room and its image with and without texture suggested that surface texture of scene objects contributes to color constancy.
关键词： color,constancy,3-D perception,object recognition,adaptation
更新于2025-09-23 15:22:29
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Psychophysical measures of visual function and everyday perceptual experience in a case of congenital stationary night blindness
摘要： An appreciation of the relation between laboratory measures of visual deficit and everyday perceptual experience is fundamental to understanding the impact of a visual condition on patients and so to a fuller characterization of the disorder. This study aims to understand better the interpretative processes by which modified sensory information is perceived by a patient with congenital stationary night blindness and the adaptive strategies that are devised to deal with their measurable visual loss. Psychophysical measurements of temporal resolution, spectral sensitivity, and color discrimination were conducted on a 78-year-old male patient with the condition, who was also interviewed at length about the ways in which his diagnosis affected his daily life. Narrative analysis was employed to identify the relation between his subjective perceptual experiences and functional deficits in identifiable components of the visual system. Psychophysical measurements indicated a complete lack of rod perception and substantially reduced cone sensitivity. Two particular effects of this visual loss emerged during interviews: 1) the development of navigational techniques that relied on light reflections and point sources of light and 2) a reluctance to disclose the extent of visual loss and resulting lifelong psychosocial consequences. This study demonstrates the valuable complementary role that rich descriptive patient testimony can play, in conjunction with laboratory and clinical measurements, in more fully characterizing a disorder and in reaching a more complete understanding of the experience of vision loss. It also evidences the particular suitability of filmmaking techniques as a means of accessing and communicating subjective patient experience.
关键词： narrative analysis,congenital stationary night blindness,quality of life,GRM6 gene,perception,psychophysics
更新于2025-09-23 15:22:29
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Influence of lighting colour temperature on indoor thermal perception: A strategy to save energy from the HVAC installations
摘要： This paper examines how the lighting colour temperature affects indoor thermal comfort. A test room with three separate environments was set and, in each one of them, a lamp with a different colour temperature was positioned to evaluate the influence of a cold, neutral and warm light. The colour temperatures of the used lamps were 11,530 K, 4,000 K and 1,772 K respectively. During each test, while complying with the EN 12464-1, a lighting level of 500 lx and a uniformity coefficient higher than or equal to 0.7 were maintained. With an air temperature of about 22 °C, 42 people were interviewed and filled a questionnaire structured according to the ISO 10551 to judge the resulting thermal comfort. The study reported a certain influence of the lighting colour temperature on people’s thermal perception which was only lower than the one related to the gender. With respect to the ASHRAE 7-point scale, being exposed to the different types of light led to a decrease (0.44 units under cold light) in the mean value of the votes given by the interviewees to judge their thermal perception. Such condition gives the possibility to increase, without varying the thermal perception of the subjects, the air temperature of 1.25 °C, 0.46 °C and 0.23 °C with cold, neutral and warm light respectively. Finally a cross tabulation analysis was performed to compare the votes of the participants before and after they were exposed to the different lights with those predicted by the Predicted Mean Vote (PMV).
关键词： PMV,Field survey,Lighting colour temperature,Thermal perception,Indoor thermal comfort
更新于2025-09-23 15:22:29
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A Global Perspective for Sustainable Highway Tunnel Lighting Regulations: Greater Road Safety with a Lower Environmental Impact
摘要： Tunnel lighting installations function 24 h a day, 365 days a year. These infrastructures have increased exponentially and now connect quite distant locations, even on different continents. This has led European administrations and international regulatory bodies to establish regulations for tunnel safety with the lowest environmental impact. However, until now, these regulations have almost exclusively focused on traffic safety, and relegated sustainability to the background. Even though they recognize the need to reduce energy consumption, they do not propose any tools for doing so. Given the impact of these installations and the lack of a specific regulatory framework, Asian countries will soon be forced either to update previous standards for tunnel lighting or elaborate new ones. A better understanding of the weaknesses of European regulations combined with a willingness to embrace innovation could position Asia as a world leader in the regulation of more sustainable road tunnels. The objective of this research was to improve the sustainability of tunnel lighting installations through new regulations or amendments to existing ones, without impairing the mental well-being of users, who could potentially be affected by energy-saving measures. Accordingly, this paper presents and analyzes a broad proposal for formulating tunnel lighting regulations. The originality of this proposal lies in the fact that it integrates road safety, lower environmental impact, and user well-being. Furthermore, it is expected to broaden the perspective of regulatory bodies and public administrations with regard to tunnel installations, which would ultimately enhance their sustainability.
关键词： driver well-being,sustainability,public perception,tunnel safety,environmental impacts
更新于2025-09-23 15:22:29
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Advances in automotive interior lighting concerning new LED approach and optical performance
摘要： Automotive interior lighting has to follow general trends in lighting and will therefore evolve toward hundreds and even thousands of RGB LEDs per car. Creating mood at day and night, pixelated sign-like information, and theater-like effects like welcome and goodbye messages are examples for outstanding user experience. Furthermore, safety features such as warnings and driving state are a must for autonomous cars. It requires new concepts for the whole interior lighting system to reach premium quality such as data rate (beyond today's bus standard for lighting), support for safety rules, compensation of temperature effects, daylight performance (including huge dimming range for night drive), uniformity in terms of luminance and color along the light guide, and mixing of red, green, and blue (RGB) with white. We report a new automotive RGB light-emitting diode (LED) system that fulfills the above requirements and saves effort as well as cost by calibration before integration. Extensive studies were performed for daylight threshold evaluation with subjects and methods for judging on uniformity for direct-lit RGB light guides based on the contrast sensitivity function and Gaussian fit of the LED luminance profile.
关键词： light guide,human centric lighting,binning,uniformity,automotive,daylight perception,LED,lighting,contrast sensitivity function
更新于2025-09-23 15:21:01
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Highlya??Transparent and Truea??Colored Semitransparent Indoor Photovoltaic Cells
摘要： Organic photovoltaic (OPV) cells are promising indoor light energy harvesters because organic materials absorb strongly in the visible range. An indoor photovoltaic (IPV) device is an effective tool for the remote off-grid wireless charging. However, as the indoor light fluxes are much weaker than the 1-Sun condition, high-performance indoor cells should have large areas in order to generate appreciable energies. They would then appear as flat, but expansive and dark objects if deployed indoors. Their presence would then alter the indoor lighting environment and affect visual perceptions. This work addresses the lighting and perception issues of IPV cells in three ways. i) A concept is proposed such that a high-efficiency, semitransparent indoor OPV cell should possess an absorbance which is mismatched with the emission spectra of the light sources. ii) It is demonstrated that bulk heterojunction (BHJ) OPV solar cells with porphyrin donors can serve as high-transparency and high-efficiency indoor light harvesters. iii) Quantitative assessment criteria are presented for the transparency and chromaticity of an indoor semitransparent OPV cell, demonstrating that porphyrin-based P2:PC71BM semitransparent BHJ cells can achieve a power conversion efficiency (PCE) exceeding 10%, and an illuminance transparency ~65%, while preserving the color perception of the light sources.
关键词： porphyrin,indoor photovoltaics,human visual perception,semitransparent devices
更新于2025-09-23 15:21:01
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[IEEE 2019 IEEE 46th Photovoltaic Specialists Conference (PVSC) - Chicago, IL, USA (2019.6.16-2019.6.21)] 2019 IEEE 46th Photovoltaic Specialists Conference (PVSC) - Sputtered Aluminum Oxide and p <sup>+</sup> Amorphous Silicon Back-Contact for Improved Hole Extraction in Polycrystalline CdSe <sub/>x</sub> Te <sub/>1-x</sub> and CdTe Photovoltaics
摘要： Previous studies have attempted to investigate the peripheral neural mechanisms implicated in tactile perception, but the neurophysiological data in humans involved in tactile spatial location perception to help the brain orient the body and interact with its surroundings are not well understood. In this paper, we use single-trial electroencephalogram (EEG) measurements to explore the perception of tactile stimuli located on participants’ right forearm, which were approximately equally spaced centered on the body midline, 2 leftward and 2 rightward of midline. An EEG-based signal analysis approach to predict the location of the tactile stimuli is proposed. Offline classification suggests that tactile location can be detected from EEG signals in single trial (four-class classifier for location discriminate can achieve up to 96.76%) with a short response time (600 milliseconds after stimulus presentation). From a human-machine-interaction (HMI) point of view, this could be used to design a real-time reactive control machine for patients, e.g., suffering from hypoesthesia.
关键词： Electroencephalogram (EEG),prediction,tactile,spatial location perception
更新于2025-09-23 15:19:57