Acquisition And Analysis System Development Of Chlorophyll Fluorescence Image Based On Labview And Matlab

As a natural probe to research plant photosynthesis,Chlorophyll fluorescence technology is fast,non-destructive,and accurate.Consequently,the technology is popular in efficient and quick acquisition of plant physiological information in protected agriculture,providing decision support for the control of the plant growth environment and fertilizer water irrigation.To conveniently and fast obtain the information of chlorophyll fluorescence of plant in greenhouse,an acquisition and analysis system for chlorophyll fluorescence image based on LabVIEW and MATLAB was designed.This easy-operating and high cost-effective system can analyze the physiological information of plants quickly and non-destructively.The main research work of this paper are as follows:(1)The overall system architecture and technical solutions was determined,according to the crop growth situation and the hardware condition.(2)According to the technical solutions,this system is mainly composed of PC,the controller,camera,light source,and slide platform.The hardware selection and organization of the whole hardware system were decided by the contrast analysis.The optimization of hardware system was accomplished by system test.(3)According to system function demand the software implementation scheme was selected,and the software was designed by this way.In the PC,the instrument control and machine vision,on basis of virtual instrument were realized by LabVIEW software and VISA,VDM,VAS and other components.Afterwards,a hybrid programming mode of LabVIEW and MATLAB was selected by comparison with other software.According to the application demand,image processing software was designed based on MATLAB.In the controller,the software which used to control the action mechanism was designed by Keil uVision5.(4)In order to obtain the optimal system parameter setting scheme,the experiment was carried out with the distance between camera and measured object,the output power of light source and the camera exposure time as variables,and the object of this experiment was pepper.The results showed,within the scope of system adjustment,if the distance between camera and measured object was shorter or the output power of light source was greater,the optical power of blade would be greater,which made the fluorescence excitation effect of chlorophyll better.If the camera exposure time was longer,fluorescent brightness of the blades collected by system would be higher.The data couldn’t normally describe the features of fluorescent image because of the high brightness of image under long exposure time.After analyzing experiment data,the final setting scheme was:when the distance between camera and measured object was 20 cm,output power of light source was greatest(in this case the optical power of blade was 9.9 mW).And the camera exposure time was 200 ms,the feature parameters of fluorescent image were the maximum effective data.(5)With chlorophyll fluorescent image collection and analysis system designed in this paper.Chlorophyll:fluorescence meter,feature parameters of the same test object,pepper leaves,respectively were collected.Significance and correlation between feature parameters of chlorophyll fluorescent image and fluorescence parameters were analyzed.The results showed that feature parameters of chlorophyll fluorescent image were significantly correlated with qL,NPQ,FM,FV/FM.R,G components and qL had high correlation,the correlation coefficient reached 0.845.G component and NPQ had moderate correlation,the correlation coefficient reached 0.548.B component and Fm had moderate correlation,the correlation coefficient reached 0.566.R,G components and FV/Fm had moderate correlation,the correlation coefficient reached 0.658.And then the regression model of related parameters was established.According to the feature parameters of chlorophyll fluorescent image,chlorophyll fluorescence parameters could be predicted by regression mode during the diagnosis of plant growth state,and then the information such as physiological status of plants and the degree of its environmental stresses could be analyzed by these data.