The color assessment cabinet has important applications in the color fields of textiles, pigments, printing and dyeing, packaging, and photography. In order to achieve the spectral matching of CIE standard illuminant D65 using monochromatic LEDs, in this paper, we use genetic algorithm (GA) as the spectral matching algorithm, measure the absolute spectra of monochromatic LEDs and establish a database, optimize the parameters of the algorithm through simulation experiments, and optimize the combination of monochromatic LEDs using decreasing experiments to achieve the purpose of using fewer kinds of monochromatic LEDs to obtain a better fit with the target spectrum. The results show that the correlation indices R^2 and RMSE of 30 monochromatic LED combinations fitting D65 spectrum are 0.905 and 0.946, respectively, with high matching degree of D65 spectrum; 16 LED combinations fitting D65 spectrum are proposed by decreasing experiments, which have good fitting effect and reduce the difficulty of engineering practice.
This study analyzed how projection display technology affect visual comfort of art museum visitors by means of both subjective and objective experiments, with 30 participants and eye-tracker as recorder.
With the continuous development and improvement of human factors lighting research, while satisfying the functional lighting of indoor spaces, people are pursuing more breakthroughs and innovations in lighting quality for health. Expanded from the traditional work surface illuminance to the spatial light distribution. This study proposed a new evaluation parameter for indoor lighting environment named as BI (Brightness Index), proposed Bav(Average Brightness) and UB(brightness uniformity) to measure the brightness and the chiaroscuro of the indoor lighting environment. Taking the classroom as an example, the accuracy and feasibility of the parameters were verified through on-site testing and simulation. Results shew the effectiveness and application potentiality in lighting design and evaluation, can well complement and improve the current lighting environment evaluation system.
We present a tunable, general-purpose, light-emitting diode-based spectrally tunable light source that achieves high-precision fitting of chlorophyll b absorption spectra from 400 to 700 nm using 11 LEDs with different peak wavelengths. The target spectrum is divided into gentle and steep segments, and the optimal number of LEDs to be used at different wavelengths is determined by the segment fitting method. Then, the results were further optimized by fitting experiments, and finally the best combination consisting of 11 different peak wavelength LEDs was obtained. The results showed that the correlation coefficient R2 reached 0.9664. The precise control of each LED current by means of the pulse width modulation signal output from the microcontroller, and the output spectrum of the system was measured using a spectrometer. The results show that the correlation coefficient R2 reaches 0.9315.
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