Simulation Of Natural Low Illumination Lighting Environment At Night And Establishment Of Reflection Spectrum Database For Natural Objects

Natural light sources such as moonlight are one of the most commonly used light sources by humans at night without artificial lighting.The characteristics of selective absorption and reflection of light on the surface of non-self-luminous objects are the basis of their recognition by the human eye.The light emitted by the light source is reflected by the non-self-luminous surface,and finally enters the human eye to form a color vision.However,natural light sources such as moonlight are seriously affected by conditions such as time and weather.The amount of spectral reflectance information on the surface of the object is large,redundant,and difficult to collect,store,and use.These factors have brought certain inconveniences to related research.With the development of science and technology,LED solid-state light source is a new choice of light source type.With its excellent characteristics,it is gradually becoming a hot spot in contemporary research.The development of related programming languages has brought many conveniences to data management.This article is based on the above research background,and carried out two scientific studies,namely the LED-based low-light illumination environment simulation at night and the establishment of the SQL Server-based natural object reflection spectrum database.The specific work completed is as follows:(1)According to the characteristics that natural light sources change greatly with time,weather and other factors,in accordance with the requirements stipulated in the national standard GB / T 6495.9-2006,the field measurement spectrum curve is measured on the local low-illumination natural environment at night in Kunming.As the target curve of the follow-up test.At the same time,96 monochromatic LED lamp beads of different wavelengths purchased from the market were measured as the composition curve of the subsequent spectral power distribution simulation experiment.Taking 50 local trees and flowers in Kunming as an example,the surface spectral reflectance is measured to provide data support for the establishment of the subsequent spectral reflectance database.(2)The spectral power distribution of the various LED lamp beads actually measured in the previous period is used as the composition curve,and the spectral power distribution of the measured low-illumination natural environment at night is used as the target curve.The spectral composition matrix is fitted using Python and the least square method.For the defects of complicated data volume and slow calculation efficiency highlighted in the experiment,weighing the pros and cons,the double exponential function is used to fit the monochromatic LED spectral power distribution curve,and then the spectral composition matrix is fitted,and finally a spectral matching degree is obtained.It is a matching structure of B-level LED.(3)Using the spectral reflectance data of 50 kinds of trees,flowers and grass leaves collected in the previous period,using SQL Server,C # and other programming languages,a simple natural object reflectance spectrum database has been developed.At present,the spectral data has been stored,searched,displayed and copied And other functions,more functions are being developed in the follow-up research.Certain convenience for the use of spectral data.