Study On The Spectral Image Characteristics Of Cabbage Leaves Under The Stress

Precision agriculture is an important direction of the development of the agriculture in our country in recent years, the implementation of precision agriculture will inevitably to information acquisition and processing plants and spectral imaging technology is indispensable in precision agriculture a nondestructive, no pollution monitoring vegetation growth. Cabbage as an important of our vegetables are planted in all parts of the country, but the diamondback moth pests when an important factor affecting the quality of cabbage yield and, therefore, it is necessary to use spectral imaging technology on cabbage suffer from spectral profile of diamondback moth pests research, provide theoretical support for planting cabbage.In this thesis according to the principle of spectral imaging technology, put forward a kind of based on liquid crystal tunable filter(LCTF) and CMOS black and white camera multi-spectral imaging system, and introduces in detail the system’s working principle, calibration, data acquisition and processing, etc. And the multi-spectral imaging system of key components of the LCTF tuning range is set to430 ~ 720 nm, the multispectral data acquisition intervals of 5 nm.The method of using adaptive band selection of collected health pests and broccoli and cabbage multispectral grayscale image grey value data for the feature band selection, and cabbage leaf for the violation of insect infestation levels, the experimental results show that the effective healthy cabbage characteristic bands for545 nm, 645 nm, 650 nm, 655 nm, and with the degree of violation, the characteristics of the cabbage band has a tendency to move in the direction of blue light.Subsequent cabbage after diamondback moth pests for seven days, this paper analyzes the spectral changes, the study found that as the side dish invaded the lengthen of time, the spectral curve will appear near 450 nm absorption valley gradually raised, 650 nm absorption valley gradually disappear. In order to eliminate the effects of environmental noise, the spectrum curve of the first derivative differential treatment, and selection of the blue, red and peaks, green area, this paperanalyzes the three spectral characteristic parameters show that the characteristic parameters will appear different degree of "red shift" and "blue shift" phenomenon,the severity of the pest in cabbage has the certain instruction function.