【作者】 刘洪见；

【导师】 郑丽敏； 廖树华；

【作者基本信息】 中国农业大学 ， 作物栽培与耕作学， 2005， 硕士

【摘要】 本文通过传统观测和数码相机拍照记载观测两种手段,对夏玉米生产发育的动态过程进行观测,分析在不同氮肥营养状况夏玉米氮肥营养变化的规律;分析了玉米不同营养状态下玉米植株形态的变化;利用图像处理技术提取了玉米颜色特征和玉米的主要形态特征;在分析玉米棒三叶(未孕穗前为玉米上展三叶)SPAD值、棒三叶叶片氮百分含量及植株百分氮含量之间关系的基础上,研究了颜色特征值与表征玉米氮营养状况的叶绿素含量、氮百分含量之间的关系;确定通过人工交互的方式下分割玉米数字图像的方法,提出了提取玉米骨架的方法,并且在提取骨架的基础上,提取叶长、弦长、株高等参数;在分析玉米颜色特征与株形特征变化规律以及颜色特征与氮营养指标之间的关系上,建立了基于图像处理技术玉米冠层信息获取系统。本文的研究结果与结论果主要如下: 1)不同氮肥处理间玉米叶面积、干物重、棒三叶叶绿素含量以及棒三叶含氮量均有差异,这一差异在低氮处理和高氮处理间非常显著;玉米的高度生长对于中低氮处理比较敏感,在高氮处理下,处理间差异不显著;在各个生育期,夏玉米棒三叶叶绿素含量和氮含量以及植株百分氮含量之间变化相互呈正线性相关;但是苗期叶绿素和含氮量的相关性不如其他生育期显著。 2)建立基于数码相机的田间图像获取技术。田间图像获取采用有约束拍摄方法,获取时间要求天气状况良好,风速小,光照均匀,光线部宜过强或者过弱,参考时间13点到15点,固定距离拍摄,数码相机参数固定,光圈(光圈值F3.5～F7.1)、曝光速度(最大快门速度1/500～1/800秒)、不采用闪光灯,焦距、拍摄角度、分辨率固定,采用比色卡等,拍摄时不宜,光线不宜过强和过弱,否则极容易曝光过强和形成阴影,不利后期图像处理即参数提取。 3)分析了玉米植株的长宽随叶序变化的规律,并用4次多项式拟合了农华103叶长和叶宽随叶序变化规律;通过分析农华103叶片的长宽比随叶序变化的规律,发现玉米叶片的长宽变化规律和氮肥处理无关,长宽比和叶序的变化的之间呈二次抛物线趋势。叶长和叶宽随叶序的变化都达到了极显著水平,提出应用数码相机来获取玉米植株株形特征的方法。 4)在比较分析三种图像分割方法的基础上,确定利用人工交互式分割法作为玉米数字图像分割方法,提取RGB和HIS颜色模式下夏玉米的颜色特征值,并对所提取的颜色特征和氮营养指标进行相关性分析,选出能够冠层氮营养特征的颜色特征,建立了基于统计颜色特征的夏玉米的氮营养状况模型。 5)利用图像处理技术获取了玉米的叶长和株高等株形参数,结合叶长以叶长宽和长宽比随叶序变化的模型建立了利用玉米侧面图像估算玉米植株的生物量以及叶面积的模型,所建立的模型经检验效果显著。更多还原

【Abstract】 Based on observations and recording by traditional means and digital camera, the dynamic growth and development of summer maize are observed, and the changes disciplinarian of nitrogen nourishment in different treatments is analyzed, and plant shape change analysised too. The color and shape features of summer maize have been obtained by image processing; based on the analysis of relations between value of tri-friut- leaf SPAD, leaf percentage nitrogen contents and plant Ipercentage nitrogen contents,the relations between color and chlorophyll content and nitrogen content are researched. Segmented the maize digtal picture by manual alternant means is decided for the segment means of the maize digtal pictures .based on analyzing the change disciplinarian of color and shape features of maize and relation between color feature and nutritional indexes, acquiring canopy information is established based on iamge processing. The following are the results and conclusions of this research:1. leaf area,dry matter weight ,chlorophyll and nitrogen content all have difference among treatments, and the difference between low nitrogen treatment and high nitrogen treatment are markedly;the plant height is more sensitive in low nitrogen treatments and have no difference high nitrogen; there are positive linear correlation between leaf chlorophyll and leaf nitrogen in all growth stadge as well as plant nitrogen content, but lower correlation between them in seedling stadge are not markedly than in the others.2. The method to obtain the digtal pictures of maize in field is established. The restrictive means to take the photos of maize in field is applied, when photos been taking ,a good weather is needed ,the sun radiant intensity have impact, the parameters of digtal cameraner required fixed .flash lamp are not t allowed to be used.and the distance of take phojoes anr been fixed.3. Anlyse the change of leavf length and leaf width with leaf sequence, and establise the models which can calculate the leaf area and biologic yield, the models are based on the shape features, disciplinarian of leaf length and width changing with leaf sequencea and the ratio length to width changing with leaf sequence.4. The color and shape features, which can token the different nitrogen levels, are abstracted and screened out in RGB color pattern and HIS color pattern. And establishe the method and model of diagnosing the status of summer maize which based on statistic color feature..5. Utilized leaf leagth and plant height which obtained by image processing, combined with the disciplinarian that leaf leangth and leaf width changed with leaf sequence, the model which used for calculating leaf area and biomass,the models are statistic significant.更多还原