Pub Date : 2023-03-20DOI: 10.1177/14771535231153780
{"title":"Opinion: Development of lighting research in China","authors":"","doi":"10.1177/14771535231153780","DOIUrl":"https://doi.org/10.1177/14771535231153780","url":null,"abstract":"","PeriodicalId":18133,"journal":{"name":"Lighting Research & Technology","volume":null,"pages":null},"PeriodicalIF":2.5,"publicationDate":"2023-03-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"91344417","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-03-20DOI: 10.1177/14771535231153774
Minchen Tommy Wei
This special issue on Lighting Research in China was initiated to raise awareness of the work of researchers from China, for whom publication in an English language journal can present a particular challenge. The seven papers included in this issue cover a wide range of topics, reflecting some of the latest research carried out by Chinese researchers. The first two papers concern interior lighting. He and Yan carried out a field study in a luminaire factory in which the light level and correlated colour temperature were varied. They found that in comparison to the baseline condition (i.e., a dark condition), the light exposure can benefit workers’ subjective alertness and sleep efficiency, especially under the condition with a higher light level or a lower Correlated Colour Temperature. In the second paper, Hou et al. investigated the characterization of colour discrimination of light sources through a psychophysical experiment using the Farnsworth-Munsell 100 Hue Test and proposed two colour discrimination scores. In comparison to other metrics, the proposed scores are based on both the colour fidelity and colour gamut characteristics of the light source. The next two papers are investigations associated with road lighting. Qin et al. investigated how driving speed affected the driver’s pupil area and fixation zones when approaching the tunnel entrance under a normal lighting condition and found the fixation area and average pupil area have a negative correlation with the driving speed. Li et al. investigated the effect of pavement reflection on road lighting performance, in terms of luminance, uniformity and threshold increment through lighting simulation, providing guidance for design process. Photometric and colorimetric characteristics are important topics in metrology. With the development of imaging technologies, the characterizations are increasingly performed using cameras and sensors, which do not have perfectly uniform responses. The two papers from Xie et al. propose methods for modelling and correcting such non-uniform responses, improving the measurement accuracy. Last but not the least, though chromatic properties of effective light are important in lighting design and rendering, they are not easy to predict, measure and visualize due to the interactions between materials and lighting. The final paper in this issue, by Yu et al., reports the investigations on the effects of inter-reflections on the structure of the physical light field for diffusely scattering scenes and shows the importance to include six-dimensional light field effects of light–material interactions in spatial designs. These seven papers are just a small sample of work carried out by Chinese lighting researchers. We look forward to further important contributions in the coming years.
{"title":"Editorial: Lighting research in China","authors":"Minchen Tommy Wei","doi":"10.1177/14771535231153774","DOIUrl":"https://doi.org/10.1177/14771535231153774","url":null,"abstract":"This special issue on Lighting Research in China was initiated to raise awareness of the work of researchers from China, for whom publication in an English language journal can present a particular challenge. The seven papers included in this issue cover a wide range of topics, reflecting some of the latest research carried out by Chinese researchers. The first two papers concern interior lighting. He and Yan carried out a field study in a luminaire factory in which the light level and correlated colour temperature were varied. They found that in comparison to the baseline condition (i.e., a dark condition), the light exposure can benefit workers’ subjective alertness and sleep efficiency, especially under the condition with a higher light level or a lower Correlated Colour Temperature. In the second paper, Hou et al. investigated the characterization of colour discrimination of light sources through a psychophysical experiment using the Farnsworth-Munsell 100 Hue Test and proposed two colour discrimination scores. In comparison to other metrics, the proposed scores are based on both the colour fidelity and colour gamut characteristics of the light source. The next two papers are investigations associated with road lighting. Qin et al. investigated how driving speed affected the driver’s pupil area and fixation zones when approaching the tunnel entrance under a normal lighting condition and found the fixation area and average pupil area have a negative correlation with the driving speed. Li et al. investigated the effect of pavement reflection on road lighting performance, in terms of luminance, uniformity and threshold increment through lighting simulation, providing guidance for design process. Photometric and colorimetric characteristics are important topics in metrology. With the development of imaging technologies, the characterizations are increasingly performed using cameras and sensors, which do not have perfectly uniform responses. The two papers from Xie et al. propose methods for modelling and correcting such non-uniform responses, improving the measurement accuracy. Last but not the least, though chromatic properties of effective light are important in lighting design and rendering, they are not easy to predict, measure and visualize due to the interactions between materials and lighting. The final paper in this issue, by Yu et al., reports the investigations on the effects of inter-reflections on the structure of the physical light field for diffusely scattering scenes and shows the importance to include six-dimensional light field effects of light–material interactions in spatial designs. These seven papers are just a small sample of work carried out by Chinese lighting researchers. We look forward to further important contributions in the coming years.","PeriodicalId":18133,"journal":{"name":"Lighting Research & Technology","volume":null,"pages":null},"PeriodicalIF":2.5,"publicationDate":"2023-03-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81936437","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-03-14DOI: 10.1177/14771535231159289
PR Dekker, A.L. van Bloois
A facility for calibration of temporal light modulation (TLM) photometers has been developed. The facility is based on a laser-fed reference integrating sphere source, the optical input power of which can be modulated with an acousto-optic modulator. A system of photodiodes, amplifiers and an analogue-to-digital converter is used to sample the temporally modulated irradiance at one of the exit ports of the source. With the facility, a TLM photometer was calibrated for display contrast ratio root mean square with an absolute combined standard uncertainty of 0.037%. In addition, the facility has been characterised with the aim of measuring flicker and stroboscopic effect, considering the Ecodesign ‘Single Lighting Regulation’. The frequency response of the facility is shown to be sufficient to accommodate measurements of flicker and the stroboscopic effect.
{"title":"Facility for calibration of photometers for measurement of temporal light modulation","authors":"PR Dekker, A.L. van Bloois","doi":"10.1177/14771535231159289","DOIUrl":"https://doi.org/10.1177/14771535231159289","url":null,"abstract":"A facility for calibration of temporal light modulation (TLM) photometers has been developed. The facility is based on a laser-fed reference integrating sphere source, the optical input power of which can be modulated with an acousto-optic modulator. A system of photodiodes, amplifiers and an analogue-to-digital converter is used to sample the temporally modulated irradiance at one of the exit ports of the source. With the facility, a TLM photometer was calibrated for display contrast ratio root mean square with an absolute combined standard uncertainty of 0.037%. In addition, the facility has been characterised with the aim of measuring flicker and stroboscopic effect, considering the Ecodesign ‘Single Lighting Regulation’. The frequency response of the facility is shown to be sufficient to accommodate measurements of flicker and the stroboscopic effect.","PeriodicalId":18133,"journal":{"name":"Lighting Research & Technology","volume":null,"pages":null},"PeriodicalIF":2.5,"publicationDate":"2023-03-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"72517127","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-02-16DOI: 10.1177/14771535231154169
F. Mahlab, H. Yamaguchi, Y. Shimozima, N. Yoshizawa, H. Cai
This joint study conducted in the United States and Japan reviewed existing illuminance measurement methods that use a conventional digital single-lens reflex camera, including (a) per-pixel illuminance calculation using non-fisheye wide-angle lenses, (b) hemispherical projection-based illuminance calculation, (c) the KU method developed by the University of Kansas (KU) and (d) the L-CEPT method developed by the Japanese team for per-pixel illuminance calculation using 180° fisheye lens. Next, laboratory and field measurements were conducted in 32 test scenarios in Kansas and Japan to improve and validate the two similar methods (c) and (d) for per-pixel illuminance calculation and compare them to the simplified method (b) using orthographic projection-based illuminance calculation. Based on the test results, the camera-aided illuminance measurement method could have an error rate of 13.7% ± 15.3% (SD) in all 32 scenarios. Large errors (>25%) were observed in six extremely dynamic gymnasiums with rapidly changing morning sunlight. Alternatively, an average error rate of 7.7% ± 7.5% was observed in the 26 test scenarios without rapidly changing direct sunlight. The simplified orthographic projection-based method could achieve the same level of accuracy as the per-pixel KU/L-CEPT method. Yet, multiple issues on camera-aided illuminance measurement still need further investigation.
{"title":"A joint validation study on camera-aided illuminance measurement","authors":"F. Mahlab, H. Yamaguchi, Y. Shimozima, N. Yoshizawa, H. Cai","doi":"10.1177/14771535231154169","DOIUrl":"https://doi.org/10.1177/14771535231154169","url":null,"abstract":"This joint study conducted in the United States and Japan reviewed existing illuminance measurement methods that use a conventional digital single-lens reflex camera, including (a) per-pixel illuminance calculation using non-fisheye wide-angle lenses, (b) hemispherical projection-based illuminance calculation, (c) the KU method developed by the University of Kansas (KU) and (d) the L-CEPT method developed by the Japanese team for per-pixel illuminance calculation using 180° fisheye lens. Next, laboratory and field measurements were conducted in 32 test scenarios in Kansas and Japan to improve and validate the two similar methods (c) and (d) for per-pixel illuminance calculation and compare them to the simplified method (b) using orthographic projection-based illuminance calculation. Based on the test results, the camera-aided illuminance measurement method could have an error rate of 13.7% ± 15.3% (SD) in all 32 scenarios. Large errors (>25%) were observed in six extremely dynamic gymnasiums with rapidly changing morning sunlight. Alternatively, an average error rate of 7.7% ± 7.5% was observed in the 26 test scenarios without rapidly changing direct sunlight. The simplified orthographic projection-based method could achieve the same level of accuracy as the per-pixel KU/L-CEPT method. Yet, multiple issues on camera-aided illuminance measurement still need further investigation.","PeriodicalId":18133,"journal":{"name":"Lighting Research & Technology","volume":null,"pages":null},"PeriodicalIF":2.5,"publicationDate":"2023-02-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89269650","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-01-28DOI: 10.1177/14771535221148736
T. Tsesmelis, N. Carissimi, Alessio Del Bue
In this paper, we propose a pipeline and benchmark, called DeepLux, for predicting illuminance on 3D point clouds. Classic algorithms for computing photometrically accurate illumination are based on numerical and analytical models which are generally computationally expensive, especially in scenarios with complex geometries. Unlike existing approaches, our algorithm is the first learning-based method that is able to predict accurate illuminance map information that could be used for real-time smart lighting applications. We also evaluate our approach on two complementary tasks, that is, light position and intensity estimation, which are important aspects in the field of lighting design. Additionally, we provide an extensive novel photometrically correct dataset, which we use for training and evaluating our approach. Experiments show that the proposed algorithm produces results on par with or even better than the state of the art (+8% average error in real tests) while achieving faster simulation timings than its analytical counterpart, especially in complex synthetic and real-world scenarios.
{"title":"DeepLux: A data-driven method and benchmark for 3D illuminance maps estimation","authors":"T. Tsesmelis, N. Carissimi, Alessio Del Bue","doi":"10.1177/14771535221148736","DOIUrl":"https://doi.org/10.1177/14771535221148736","url":null,"abstract":"In this paper, we propose a pipeline and benchmark, called DeepLux, for predicting illuminance on 3D point clouds. Classic algorithms for computing photometrically accurate illumination are based on numerical and analytical models which are generally computationally expensive, especially in scenarios with complex geometries. Unlike existing approaches, our algorithm is the first learning-based method that is able to predict accurate illuminance map information that could be used for real-time smart lighting applications. We also evaluate our approach on two complementary tasks, that is, light position and intensity estimation, which are important aspects in the field of lighting design. Additionally, we provide an extensive novel photometrically correct dataset, which we use for training and evaluating our approach. Experiments show that the proposed algorithm produces results on par with or even better than the state of the art (+8% average error in real tests) while achieving faster simulation timings than its analytical counterpart, especially in complex synthetic and real-world scenarios.","PeriodicalId":18133,"journal":{"name":"Lighting Research & Technology","volume":null,"pages":null},"PeriodicalIF":2.5,"publicationDate":"2023-01-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77667363","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-01-21DOI: 10.1177/14771535221145672
N. Yoshizawa, R. Schregle, K. Komazawa, K. Ootori, T. Okamoto
This paper proposes a new method to depict the light field based on the volume photon mapping algorithm. In the context of the light field simulation, a participating medium serves to deposit the photons, but does not disturb their propagation. The photons are therefore neither scattered nor absorbed in order to preserve their energy and trajectory within the environment, thus providing an unbiased luminance distribution. A visualisation of the photon distribution enables an intuitive interpretation of the light propagation that helps designers to understand the basic light field in the space. In addition to visualisation, the magnitude of the simulated physical light field can be numerically evaluated from the volume photon map distribution using, for example, cubic and scalar illuminance. This can further inform the designer on the light density distribution in the space, since the latter directly correlates with the density of the photons, and therefore the scalar illuminance. The accuracy of the proposed method was ascertained by comparing it with the original RADIANCE. Furthermore, its advantage in visualisation was demonstrated using a complex case study involving strong indirect lighting, reinforced by a comparison of the simulation and measurement in the actual space. In addition, photon mapping was found to evaluate illuminance in multiple grid points much faster than RADIANCE Classic, notably due to the complex ambient lighting from specular reflections. The implementation of the specialised volume photon mapping software is now part of the RADIANCE software and is available as a lighting research tool for the community.
{"title":"Photon flow: A three-dimensional expression of the light field using volume photon mapping","authors":"N. Yoshizawa, R. Schregle, K. Komazawa, K. Ootori, T. Okamoto","doi":"10.1177/14771535221145672","DOIUrl":"https://doi.org/10.1177/14771535221145672","url":null,"abstract":"This paper proposes a new method to depict the light field based on the volume photon mapping algorithm. In the context of the light field simulation, a participating medium serves to deposit the photons, but does not disturb their propagation. The photons are therefore neither scattered nor absorbed in order to preserve their energy and trajectory within the environment, thus providing an unbiased luminance distribution. A visualisation of the photon distribution enables an intuitive interpretation of the light propagation that helps designers to understand the basic light field in the space. In addition to visualisation, the magnitude of the simulated physical light field can be numerically evaluated from the volume photon map distribution using, for example, cubic and scalar illuminance. This can further inform the designer on the light density distribution in the space, since the latter directly correlates with the density of the photons, and therefore the scalar illuminance. The accuracy of the proposed method was ascertained by comparing it with the original RADIANCE. Furthermore, its advantage in visualisation was demonstrated using a complex case study involving strong indirect lighting, reinforced by a comparison of the simulation and measurement in the actual space. In addition, photon mapping was found to evaluate illuminance in multiple grid points much faster than RADIANCE Classic, notably due to the complex ambient lighting from specular reflections. The implementation of the specialised volume photon mapping software is now part of the RADIANCE software and is available as a lighting research tool for the community.","PeriodicalId":18133,"journal":{"name":"Lighting Research & Technology","volume":null,"pages":null},"PeriodicalIF":2.5,"publicationDate":"2023-01-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86940903","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-01-12DOI: 10.1177/14771535221143973
I. Elgadra, S. Fotios
Cultural factors in Libya (and other Muslim countries) require female privacy to be maintained. Outside the home, females must wear clothing that reveals only the face and hands. When inside the home and located near windows, a similar degree of clothing cover or window treatment is required. This reduces exposure to natural daylight, with resultant reduction in health benefits of daylight. We are therefore investigating the degree to which window treatments offer sufficient privacy to permit relaxed clothing in the home. Two window treatments were tested: horizontal blinds and frosted glass, varying the free area and degree of frosting, respectively. The degree of privacy offered was operationalised by identification of the clothing level worn by a target behind the window treatment, the aim being to reduce identification to a chance level. For 0.3 s observations, only the extreme level of each treatment (horizontal blinds set to 3% free area and distortion level 20 for the frosted glass) led to chance levels of clothing identification, for both actors. For 3.0 s observations, there were significant differences in clothing identification, suggesting insufficient privacy.
{"title":"Examining female visual privacy as a function of window treatments","authors":"I. Elgadra, S. Fotios","doi":"10.1177/14771535221143973","DOIUrl":"https://doi.org/10.1177/14771535221143973","url":null,"abstract":"Cultural factors in Libya (and other Muslim countries) require female privacy to be maintained. Outside the home, females must wear clothing that reveals only the face and hands. When inside the home and located near windows, a similar degree of clothing cover or window treatment is required. This reduces exposure to natural daylight, with resultant reduction in health benefits of daylight. We are therefore investigating the degree to which window treatments offer sufficient privacy to permit relaxed clothing in the home. Two window treatments were tested: horizontal blinds and frosted glass, varying the free area and degree of frosting, respectively. The degree of privacy offered was operationalised by identification of the clothing level worn by a target behind the window treatment, the aim being to reduce identification to a chance level. For 0.3 s observations, only the extreme level of each treatment (horizontal blinds set to 3% free area and distortion level 20 for the frosted glass) led to chance levels of clothing identification, for both actors. For 3.0 s observations, there were significant differences in clothing identification, suggesting insufficient privacy.","PeriodicalId":18133,"journal":{"name":"Lighting Research & Technology","volume":null,"pages":null},"PeriodicalIF":2.5,"publicationDate":"2023-01-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82853099","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-01-12DOI: 10.1177/14771535221142804
J. Lokesh, A. Padmasali, MG Mahesha, S. Kini
The spectral power distribution (SPD) is the true fingerprint of a light source and is mainly dependent on electrical and thermal loading. Both the photometric and colorimetric quantities are originally extracted from SPD. Therefore, the dynamic prediction of SPD for LED has become an important aspect to evaluate the performance of LED during its time of operation. Generally, the statistical models are used to predict SPD. However, the statistical model with more than two input makes the system complex and time demanding. Artificial Neural Network (ANN) models, on the other hand, can help with this problem. The major goal of this research is to improve the utility of ANN in lighting applications. This is demonstrated by various neural network (NN) structures referred as models 1, 2 and 3 with combinations of varied neurons and hidden layers (HLs) to forecast SPD for various electrical and thermal stress levels at zero hours. The results are compared and based on absolute prediction error (APE) set to 5%, model 1 is considered as the best model for the SPD prediction. In addition, the time-based SPD prediction with model 1 is investigated using temperature, wavelength and time as input parameters for the LED luminaire and is validated.
{"title":"Comparison and validation of neural network models to estimate LED spectral power distribution","authors":"J. Lokesh, A. Padmasali, MG Mahesha, S. Kini","doi":"10.1177/14771535221142804","DOIUrl":"https://doi.org/10.1177/14771535221142804","url":null,"abstract":"The spectral power distribution (SPD) is the true fingerprint of a light source and is mainly dependent on electrical and thermal loading. Both the photometric and colorimetric quantities are originally extracted from SPD. Therefore, the dynamic prediction of SPD for LED has become an important aspect to evaluate the performance of LED during its time of operation. Generally, the statistical models are used to predict SPD. However, the statistical model with more than two input makes the system complex and time demanding. Artificial Neural Network (ANN) models, on the other hand, can help with this problem. The major goal of this research is to improve the utility of ANN in lighting applications. This is demonstrated by various neural network (NN) structures referred as models 1, 2 and 3 with combinations of varied neurons and hidden layers (HLs) to forecast SPD for various electrical and thermal stress levels at zero hours. The results are compared and based on absolute prediction error (APE) set to 5%, model 1 is considered as the best model for the SPD prediction. In addition, the time-based SPD prediction with model 1 is investigated using temperature, wavelength and time as input parameters for the LED luminaire and is validated.","PeriodicalId":18133,"journal":{"name":"Lighting Research & Technology","volume":null,"pages":null},"PeriodicalIF":2.5,"publicationDate":"2023-01-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75056154","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-01-04DOI: 10.1177/14771535221127442
X. Xie, Q. Sun, J. Gong, Y. Shang, Z. Zhang, N. Liao
In this paper, a theoretical analysis reveals that system radiation transmission nonuniformity and system radiation conversion nonuniformity have different forms. A colour imaging system response nonuniformity model is then proposed according to the two kind of nonuniformity of three channels. The model includes two models, one for brightness and one for chromaticity. The brightness model is built according to the nonuniformity of single channel. The chromaticity model is built as an error ellipse in the chromaticity diagram. The error ellipse can be also used as a representation parameter of the radiation conversion nonuniformity. The proposed models were verified using three commercial digital cameras. The experimental results show that the proposed nonuniformity model is correct. Moreover, the proposed representation parameter is an effective way to evaluate and characterize the nonuniformity of a colour imaging system. This research has value as a reference for the correction and evaluation of response nonuniformity in colour imaging systems.
{"title":"Response nonuniformity modelling for colour imaging systems","authors":"X. Xie, Q. Sun, J. Gong, Y. Shang, Z. Zhang, N. Liao","doi":"10.1177/14771535221127442","DOIUrl":"https://doi.org/10.1177/14771535221127442","url":null,"abstract":"In this paper, a theoretical analysis reveals that system radiation transmission nonuniformity and system radiation conversion nonuniformity have different forms. A colour imaging system response nonuniformity model is then proposed according to the two kind of nonuniformity of three channels. The model includes two models, one for brightness and one for chromaticity. The brightness model is built according to the nonuniformity of single channel. The chromaticity model is built as an error ellipse in the chromaticity diagram. The error ellipse can be also used as a representation parameter of the radiation conversion nonuniformity. The proposed models were verified using three commercial digital cameras. The experimental results show that the proposed nonuniformity model is correct. Moreover, the proposed representation parameter is an effective way to evaluate and characterize the nonuniformity of a colour imaging system. This research has value as a reference for the correction and evaluation of response nonuniformity in colour imaging systems.","PeriodicalId":18133,"journal":{"name":"Lighting Research & Technology","volume":null,"pages":null},"PeriodicalIF":2.5,"publicationDate":"2023-01-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77060947","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-01-01DOI: 10.1177/14771535221142639
P. Thorns
There is a trend towards smart buildings, smart cities and smart everything else. This is generally a good direction of travel, as there is the potential to save significant amounts of energy while at the same time creating better, more useful spaces for people. Using energy to light a space poorly is always a waste, no matter how low energy the lighting installation may be. Occupants will not enjoy the space and will not operate efficiently within it. Using the minimum energy required to correctly light a space is a more efficient use of energy, and smartness has the potential to facilitate this. However smartness comes with a caveat or two.
{"title":"Editorial: Towards smart spaces","authors":"P. Thorns","doi":"10.1177/14771535221142639","DOIUrl":"https://doi.org/10.1177/14771535221142639","url":null,"abstract":"There is a trend towards smart buildings, smart cities and smart everything else. This is generally a good direction of travel, as there is the potential to save significant amounts of energy while at the same time creating better, more useful spaces for people. Using energy to light a space poorly is always a waste, no matter how low energy the lighting installation may be. Occupants will not enjoy the space and will not operate efficiently within it. Using the minimum energy required to correctly light a space is a more efficient use of energy, and smartness has the potential to facilitate this. However smartness comes with a caveat or two.","PeriodicalId":18133,"journal":{"name":"Lighting Research & Technology","volume":null,"pages":null},"PeriodicalIF":2.5,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79523651","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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