Remote Automatic Monitoring For Crop Canopy Leaf Color Change Technology

Monitoring and management is the key to ensure the production and quality of crops. The crop canopy is the main organ for photosynthesis and transpiration, the color of leaf is an important basis for the diagnosis of nitrogen nutrition, the content of chlorophyll and the estimation of leaf water content, automatic monitoring leaf color change can grasp and analyze the growth of crops. The traditional nitrogen monitoring is using chlorophyll meter, but someone need to go to the field, if the diagnosis is long time and large area, it will spend a lot of manpower, and the chlorophyll meter is expensive. This paper mainly use computer vision technology to remotely monitor the leaf color of crop canopy, the main work of this paper is as follows:Firstly, the significance of the research on the remote automatic monitoring technology of crop canopy leaf color change and the specific situation of the research at home and a broad are introduced. The methods used in these researches and the results obtained are described, then summarizes some problems and shortcomings in theses researches.Then the method of automatic extraction green crop target was studied. First, use median filter to reduce the noise in the original image, then use improved super green algorithm to get the gray scale image which the target is strengthened, after that use the Otsu algorithm to get binary image, then use connected domain labeling algorithm and area filtering to fill the holes in binary image, at last get the binary image of target. Restore colors in binary image, calculate the average value L component value of the Lab color space in the image, use the average value which has been calculated to instead of the L values of the original image. Executive target extraction again, high reflection and shadow areas can also be extracted from the image when the light is not so right.When the crop target image is got, next work is to analyze and express the color of the image. Firstly, describe the color system, then the Lab color space is selected to analyze and describe the color, and the RHS Royal Garden Association color card is used to express the result of color., find the closest color in RHS card by calculate the color characteristics of the target image. In order to quantify green crop leaf color change, the concept and calculation formula of chromatic aberration is introduced, the change of leaf color is indicated by the chromatic aberration. Then, the effect on color because of light in different weather was proposed, the L component value obtained from overcast which the light is close to the standard light source is set to the standard value, under other weather conditions, reduce the effect of light by fix the L value. Monitoring the same crop in a month’s time, take picture at the same time every day, record the daily weather, color temperature, Lab value, result color, chromatic aberration and fixed chromatic aberration, then the data recorded in the experiment were analyzed.At last, the hardware equipment of the crop canopy leaf color remote automatic monitoring system was set and the server software system is designed and implemented. Through needs analysis, and come to a conclusion that the system needs solar charger, WiFi remote control intelligent switch, Wi Fi camera and a computer for the image processing, then integrate these hardware. At the server side, C# language is used to compile the system for automatic extraction of targets, calculation color, output and storage results.