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Light Pollution and Prevention: An Introduction
Published in Tuan Anh Nguyen, Ram K. Gupta, Nanotechnology for Light Pollution Reduction, 2023
Abhinay Thakur, Richika Ganjoo, Ashish Kumar
G. Gagliardi et al. [20] demonstrated an urban smart lighting network that can adjust the lighting brightness of street lamps independently using data from vehicles (buses, cars, motorcycles, and bikes) and/or walkers in a given region. The system can adjust the illumination brightness based on the demands of the user, lowering energy consumption. Regional controllers, video cameras, motion sensors, and electronic equipment for video processing are used to achieve this. The sensor inputs are stored in this way so that a 1–10 V control input voltage can be applied to the luminaire or controller to fade the lights optimally. Monitoring can be done on a decentralized basis on each street lamp or a group of them. Experiments show that the proposed architecture can save up to 65% of energy when compared to a normal street lamp system.
Digital Image Fundamentals
Published in Sheila Anand, L. Priya, A Guide for Machine Vision in Quality Control, 2019
We saw that intensity of light refers to the amount of light or light energy of a pixel, which is expressed as a numeric value. Brightness is a visual perception and refers to the overall lightness or darkness of an image. When brightness is high, the whitest pixels are saturated; while the blackest pixels are saturated when brightness is low. For instance, in a monochrome image, when many of the pixels in the image have a value of 0, the image would appear dark. Conversely, when many of the pixels have a value of 1, the image would appear bright. Proper brightness is therefore important to perceive the details in an image. For example, brightness of an image can determine whether an object in the image is visible or becomes invisible as it merges with the background. That brings us to the description of contrast, which is the difference in brightness between objects or regions in the image. Figure 2.8 shows actual image and its brightness and the contrast version of the same.
The Visual Environment: Measurement and Design
Published in R. S. Bridger, Introduction to Human Factors and Ergonomics, 2017
The luminance of an object depends on the light it emits or reflects toward the eye. It is measured in candelas per square meter and corresponds roughly to brightness (although brightness perception depends on other factors such as contrast). In the example above, if the inside of the sphere is a perfect reflector of light, then the luminance will be the same as the illuminance. The percentage of the incident light reflected by a surface depends on the reflectance of the material. Reflectance is defined as the ratio of luminance to illuminance. White paper has a reflectance of about 95%, white cloth about 65%, newspaper about 55%, and plain wood about 45%. Matte black paper has a reflectance of about 5%. More formally, reflectance is given by Reflectance=Luminance×πIlluminance
Analysis of heat diffusion considering driving images on 6-inch flexible AMOLED display
Published in Journal of Information Display, 2023
Chang Hoon Jeon, Ji Woong Park, Byung Wook Kang, Su Hyuk Jang, Kyung Joon Kwon, Soon Kwang Hong, Yong Min Ha, Jin Jang
Figure 5(a–f) shows the comparison between the conventional and current method using the heat diffusion equation (6). Note that the conventional method does not take into account the changes according to driving images. The maximum brightness is 650 nits, and the evaluation is carried out at room temperature.