Study On Measuring Precision Of The SM Light Environment Test System

The physical environment of buildings qualities are closely related to theworking, learning and living situations of human being. Among them, lightenvironment has great impact on person’s health and psychology, with thepopularization of the new illumination technologies, low carbon economicdevelopment is being pushed. Scientific light environment evaluation andreasonable light environment design, must be based on the research of thephysical properties. Light environment test technology will keep going alongwith the same develop ways that the computer technologies are widely utilized inscientific and technical areas.Based on computer and digital camera technologies, SM Light EnvironmentTest System is a multi-function tool which can provide many indexes of the lightenvironment; it’s also an incredible invention preceding many years research ofthe owner. So it’s very important for the precision and complication of the systemfunction to keep every main node of the early calibration working well.At the first stage, the paper locates the research on theories and technologiesof the calibration process, and clarifies them as the theory foundations for thelater experiment applications. During calibration experiments which are based ondigital camera herent characteristics and a lot of sample research, influencefactors such as skylight variations, large dynamic range, glow and fog block,white balance are given. Through the research, we offers the improvementapproaches and solutions to the influence factors above, regulations to theexperiment scheme, process, device operation, notes and attentions areformulated.At the stage of image acquisition and data processing, with the theories ofcolourometry, digital camera image characteristics and computer graphicstechnologies,5study nodes are formed, they are image processing and analysis,correction to RGB transform coefficients, color coordinates measuring, theinfluence of aperture and shutter speed variation, and stability of the ISOcalibration. During complete study, their own solutions are concluded. At thesame time, calibration software flowchart is being researched and developed, as one of the main results, SM computer calibration program is introducedthoroughly.At the stage of the application and extend research on SM Light EnvironmentTest System,4parts are spread and discussed, they are gray scale difinition, RGB+white LED light dimming experiment based on PWM technology, the normallens view angle calculation, and the calibrations of the simulated scenes whichare built with3d aid design software, all the study above achieves the expectedeffect and some related conclusions are also drawn.From this paper, we can make the influence factors which are often ignoredquantitative by data processing, so the controlled principles are formulated by theanalysis result, regulations to the experiment scheme, process, device operation,notes and attentions are also the main achievement. In the paper, the EV virtualvalue theory formulas are derived by abundant data calculations; gray scaledifinition methods are discussed meticulously. SM computer calibration programis invented with the guide of the calibration software flowchart. RGB+whiteLED light dimming experiment scheme is basically fulfilled, with the joint of thePWM technology, the light dimming system will get realized soon; the Mentalray lighting system is calibrated and connected to SM Light Environment TestSystem, in3ds max design. From this point, we have added new functions whichcan be good fusions of light environment measure and computer aid design in SMLight Environment Test System.