The Design And Implementation Of Multiplexed Illumination For Variable Lighting In 3D Capture System

A wide range of dynamic light field acquisition system can capture large or multiple moving targets from the different surface reflection properties of light direction,movement and environmental light information,in order to provide the reliable premise and guarantee for realizing the realistic reappearance of 3D scene in arbitrary lighting environments.However,during variable illumination capturing,it's unable to capture the correct and clear images of light fields for the wide range of venues and a larger number of light sources etc.To the above questions,this paper designs a variable illumination 3D capture system based on multiplexed illumination,which increases the number of light source in capture time,improves the using rate of light source,reduces the image noise of single light source after de-multiplexed illumination,single source of image noise,and improves the quality of images of light fields.And this paper also proposes a new fast multiplexed illumination algorithm based on Hadamard matrix,which decreases computational complexity from N² to Nlog₂N improving the computation efficiency of de-multiplexed illumination by 26 times.The following is the main content of paper:First chapter mainly introduces 3D capture system on the domestic and international research as well as trend and difficulty.Second chapter studies illumination control technology in 3D capture system and introduces constant illumination control system and variable illumination control system.Moreover,it gives the details about the advantages and disadvantages of 3D capture technology based on single light source and based on multiplexed illumination,and communication method of 3D capture system controlling network.Third chapter proposes a multiplexed illumination algorithm based on Hadamard matrix,also proposes a new fast de-multiplexed illumination algorithm based on Hadamard matrix exploiting factorization of Hadamard matrix.This algorithm increases the number of light source and brightness at every captures,improves the sensitometry and articulation of image capture and the computation efficiency of de-multiplexed illumination in case of signal to noise ratio of image.Fourth chapter uses TrueTime toolkit based on Matlab/Simulink to build the emulation platform based on the emulation CAN network.System emulates 97 control nodes and 191 sets of light source change,verifies the probability of multiplexed illumination algorithm based on Hadamard matrix in 3D capture system,and tests network communication protocol about real time for controlling system and accuracy for controlling light in system through experiment.Fifth chapter realizes hardware platform of variable illumination 3D capture system based on multiplexed illumination.The variable illumination 3D capture system based on fast Hadamard transform designed by this paper is experimented on relevant variable illumination image capture in actual 3D image capture cage system and tests fast Hadamard transform algorithm for demultiplexed illumination and the result of emulation experiment.The results shows the multiplexed illumination method certainly improves the quality and efficiency of image capture,which increases the signal-noise ratio of the image from 1.826 to 2.325.De-multiplexed illumination method based on fast Hadamard transform decreases the computing times from N² to Nlog₂N.Meanwhile,the rate of calculation speed has increased by 26 times than traditional method.