The Study Of Standards For Tobacco Leaf Image Acquisition Technology And Rating Characteristics Of Tobacco Purchase Quality

Tobacco purchase quality is an important reference for its grade. Currently, tobacco purchase quality is mainly estimated by human experiences that are sometimes subjective, and many factors are rather unclear, which leads to the unstable assessments of tobacco quality, results in the dissensions in tobacco purchasing, discouragement of farmers and the loss of state property. So it's necessary to develop tobacco purchase quality regulations based on digital technology. In this dissertation, tobacco image collection regulations, transmission images, color (shape) references and the spectral absorptions of tobacco leaf were studied. The main resultes was summarized as follows:1. Environmental conditions such as lamp voltage, camera brand, focus distence, image resolution, shutting model and the stableness of lighting were studied to address the effects on the recognition of tobacco images. The color reference plate was introduced to eliminate the errors and calculate the absolute size of the tobacco. The stableness of the white reference plate was evaluated. The relative color was used to fast and timely correct the errors in tobacco image recognition. This study regulates the tobacco leaf collection environment. And laid foundations for the standardization of digital tobacco image collection framework.2. The tobacco leaves absorbance, reflection and transmission of visible light were studied. The special lamp box was designed based on the absorbance difference of transmitting light. The segmentation method of tobacco images was proposed based on the characteristics of the transmitting spectral. The results showed that the segmentation accuracy is higher than the method of point statistics. And the average pixels are 0.65% more than that of point statistics per leaf and the original information was well kept. The transmission image can not only trade off the background effects, and extend the characteristic parameters for tobacco images. The method presented maintains the objective characteristics of images, which help the increasing of segmentation accuracy and lay foundation for further studies on features of tobacco leaf. And also can serve as example for the recognition of other crop leaves.3. The measurements such as length, width, area and color of tobacco leaf were measured using the reference white plane. The mentioned measurements were measured by hand and by computer image processing method, respectively for the 11 tobacco leaf samples. The results showed there is a good relationship between the results obtained by different ways, and the average error for length is 2.59 cm, the corresponding relative average error is 5.11%, and the average error for width is 0.88 cm, the corresponding relative average error is 4.84%. The color characteristics of the tobacco leaf were also studied under RGB and HIS systems. It was concluded that the lemon and orange tobacco leaf can be distinguished by using the relative saturation. Based on the research mentioned above, it was found that in conjunction with the reference method, the image processing method could be used to extract the feature parameters of tobacco leaf such as shape and area, and relative color can be used to discriminate the color of tobacco leaf. The findings of the paper are very helpful for the digital rating for tobacco quality.4. The absorption characteristics of tobacco leaf in visible light were investigated to address the relationship between the tobacco origination, quality and classes. In this dissertation, the GFY-160 fluorescence spectrometer was employed to measure the intensity of the transmitted light at 5 nm intervals from 320 to 810 nm. The upper, middle and lower part of the tobacco leaf from Enshi, Yunnan, Linqu and from same area were conducted transmission experiment and the transmitted light were measured accordingly. The results revealed the tobacco leaf absorb blue light greatly, and in the transmission features, the ratio of blue and orange (B/O) and green and orange (G/O) change regularly with the different parts of the leaf while the ratio of red and orange (R/O) didn't show the similar rule. And the R/O in the upper part of the leaf are all over 50%. The absorption features can be used to develop the quantitative rating systems for the tobacco leaf.