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1.
基于颜色分形的水果计算机视觉分级技术   总被引:52,自引:12,他引:40  
通过对不同着色等级的水果分析,以各色度在水果表面分布的分形维数为特征进行分级,该特征值不仅考虑了各色度点的累计特性,而且考虑了色度点空间分布特性,使颜色分级更符合实际情况。将各色度域分形维数作为模式处理,建立了人工神经网络识别模型。学习后的模型分级正确率高,达到95%,能够满足计算机视觉实时分级水果生产线的要求  相似文献   

2.
基于模糊彩色聚类方法的西红柿缺陷分割研究   总被引:13,自引:6,他引:7       下载免费PDF全文
缺陷的检测一直是应用计算机视觉技术进行水果自动分级的难点。在HSL颜色模型的基础上,提出了基于模糊颜色聚类的缺陷分割方法。将RGB颜色模型转化为HSL颜色模型;用三角隶属度函数定义H、S、L模糊集,进而构成模糊颜色集;在模糊颜色的基础上,定义模糊颜色相似度测度,分析两种模糊颜色的形似性。将该分割方法应用于西红柿的缺陷分割,试验表明:准确率达96%。  相似文献   

3.
用遗传神经网络方法进行苹果颜色自动检测的研究   总被引:20,自引:5,他引:15       下载免费PDF全文
该文通过计算机视觉技术获取苹果的色度直方图并提取其表面颜色特征,采用先进的遗传算法建立了一个多层前馈神经网络系统,从而实现了苹果成熟度的自动判别。实测表明,该方法准确率较高,并具有鲁棒性、灵活性和高速度。  相似文献   

4.
基于压力和图像的鲜玉米果穗成熟度分级方法   总被引:2,自引:1,他引:1  
为实现鲜玉米果穗成熟度等级的客观评定,提出了基于压力传感器和计算机视觉技术的综合分析方法。研制了玉米果穗成熟度检测装置,提取纹理信息所得惯性矩和压力检测装置所得最大压力值作为鲜玉米果穗成熟度等级评定的特征参数,通过系统聚类分级研究,确定成熟度等级为3级。采用主成分分析法对11个颜色特征进行优化筛选,用第一、二主成分可综合反映11个颜色特征的分级信息,实现了参数的降维。试验结果表明:以最大压力值、惯性矩、颜色特征主成分分析第一、二主成分值作为构建概率神经网络的输入,进行鲜玉米果穗成熟度等级评定,正确率为96.67%。结合压力传感器和计算机视觉技术可实现对鲜玉米果穗成熟度的准确分级。  相似文献   

5.
小麦生长信息计算机视觉检测技术研究   总被引:11,自引:2,他引:9  
以计算机视觉检测小麦生长信息为目的,建立了计算机视觉系统以获取小麦图像。在分析小麦生长特性的基础上,提出了用小麦叶片和茎秆之间的叉点数来检测叶数;用色相表示小麦叶片的颜色,对小麦叶片的色相值进行了检测。并在中文Windows 98平台上用Visual C++6.0开发研制了检测软件。  相似文献   

6.
苹果品质动态无损感知及分级机器手系统   总被引:1,自引:1,他引:0       下载免费PDF全文
彭彦昆  孙晨  赵苗 《农业工程学报》2022,38(16):293-303
为了实现灵活高效的苹果多品质指标检测分级,基于机器视觉技术及可见/近红外光谱技术,开发了用于苹果内外部品质无损感知及分级的机器手系统。机器手系统采用六轴机械臂搭载自行研发的末端执行器,末端执行器上装载有光学传感器与抓取结构,可以抓取流水线上的苹果并同时采集苹果的光谱进行糖度检测。使用CMOS相机采集苹果图像,训练并使用PP-YOLO深度学习目标检测模型处理采集的苹果图像,计算苹果的坐标位置实现苹果的动态定位,并获取苹果的果径大小、着色度信息实现外部品质检测。采集苹果样本光谱,结合不同的光谱预处理方式,利用偏最小二乘(Partial Least-Square,PLS)方法进行建模分析。试验结果表明,使用PP-YOLO目标检测算法处理图像和计算苹果位置,其识别速度为38帧/s,极大地提高了检测速度。使用归一化光谱比值法(Normalized Spectral Ratio,NSR)作为预处理算法的糖度建模结果较佳。采用NSR+CARS(Competitive Adaptive Reweighted Sampling,竞争性自适应重加权算法)作为机器手的动态光谱模型效果较佳,该动态光谱模型相关系数Rv为0.958 9,验证均方根误差RMSEV(Root Mean Squared Error of Validation)为0.462 7%,与静态下建立的模型相比,机器手在动态状态下采集光谱对所建立的预测模型的预测效果影响较小。对整体机器手系统进行了试验验证,机器手在工作时能够无损伤地抓取苹果,给出果径大小、着色度、糖度3个检测指标并依据指标自动划分等级,然后依据等级信息分级。随后测定了3个指标的实测值与预测值进行分析,果径大小的预测相关系数为0.977 2,均方根误差为1.631 5 mm;着色度的预测相关系数为0.967 4,均方根误差为5.973 4%;糖度的预测相关系数为0.964 3,均方根误差为0.504 8%,预测结果与真实值均具有较强的线性关系和较低的预测误差,机器手系统分级正确率为95%,完成一颗苹果的定位、抓取、检测、分级和放置的时间约为5.2 s,具有较好的工作可靠性,研究结果为苹果多品质指标的高效检测提供参考。  相似文献   

7.
果型综合评价系统中的退火演化和神经网络融合方法研究   总被引:4,自引:1,他引:3  
应用计算机视觉技术获取了国光、富士和黄元帅三个不同品种苹果的形状特征参数,采用退火演化算法及神经网络“融合”方法建立了分级合作的层次处理自动评价系统,实现了对果型的快速、准确综合判别。实验表明,该方法准确率达到95%,并具有较好的鲁棒性和灵活性,能够满足多品种、大批量实时分级的需要。  相似文献   

8.
建立了计算机视觉系统获取番茄的图像,并将RGB值转换成HIS值,通过H值提取番茄表面颜色特征。采用遗传算法训练的多层前馈神经网络实现番茄成熟度的自动判别。实验表明:该方法准确率达到94%。  相似文献   

9.
自然环境下果实的准确分割与快速识别是采摘机器人作业面临的难题之一。针对自然环境中的成熟苹果,该研究提出一种基于Otsu与分水岭相结合的两级分割算法与区域标记梯度Hough圆变换的苹果识别方法。首先,使用亮度自适应校正算法对表面亮度分布不均的苹果图像进行校正,增强图像的细节信息。结合果实颜色特征,提取YCbCr颜色空间的Cr分量图像作为预处理样本。然后,采用改进后的Otsu算法进行初次分割,得到苹果目标的二值图像,该算法通过引入形态学开-闭重建滤波去除大量背景噪声,通过缩减灰度级遍历范围提高分割速率。采用基于距离变换的分水岭算法进行二次分割,分离粘连果实区域,提取目标苹果的外部轮廓。最后,在轮廓外设置最小外接矩形标记有效区域,在标记区域内进行梯度Hough圆变换实现苹果目标的自动识别。对自然环境中采集的200幅苹果图像进行测试,并与传统梯度Hough圆变换方法进行对比,本文方法在顺、逆光下的识别准确率为90.75和89.79%,比传统方法提高了15.03和16.41%,平均识别时间为0.665和0.693 s,比传统方法缩短了0.664和0.643 s。所提的两级分割算法不仅可以从复杂环境中准确分割果实目标区域,而且可以从粘连果实区域中提取单个果实边界。利用区域标记的梯度Hough圆变换方法能够快速准确地对果实进行识别。研究结果能满足苹果采摘机器人对不同光照下目标识别速度和精度的要求,可为苹果等类球形果实的快速识别提供参考。  相似文献   

10.
基于计算机视觉技术的油菜冠层营养信息监测   总被引:3,自引:1,他引:2  
为了探讨利用计算机视觉技术监测油菜长相长势的可行性,在大田自然条件下,用数码相机构建了计算机视觉系统,获取、分割图像,用逐步回归的方法建立了用颜色值监测叶绿素含量、全氮含量、碳氮比值的最优模型,模型具有较好的预测性。试验结果表明:在大田自然光照条件下,用数码相机采集油菜图像,监测冠层叶绿素含量、全氮含量、碳氮比等生理指标是可行的。  相似文献   

11.
低氮和干旱胁迫对富士和秦冠生长及氮素利用的影响   总被引:2,自引:2,他引:0  
【目的】以富士(Fuji)、 秦冠(Qinguan)嫁接在平邑甜茶(Malus hupehensis Rehd.)上的当年生盆栽苗为试验材料,采用砂培方法,研究了缺氮胁迫和干旱对富士和秦冠生长情况、 光合参数、 植株各部位氮磷钾含量及氮素利用效率的影响,分析比较了低氮干旱条件下富士和秦冠生长及氮素利用的差异,以期为果树生产高效肥水利用提供理论指导。【方法】试验共设四个处理: 正常氮正常水(ZZ)、 低氮正常水(DZ)、 正常氮干旱(ZG)、 低氮干旱(DG)。氮素和水分均设置两个水平,分别为正常氮(6 mmol/L NO-3-N)、 低氮(0.3 mmol/LNO-3-N)、 正常供水(保持盆中砂子相对含水量为饱和含水量的80%~85%)、 干旱处理(保持盆中砂子相对含水量为饱和含水量的60%~65%)。【结果】富士和秦冠的生物量(茎和叶)、 株高茎粗等生长指标以及光合速率、 气孔导度、 蒸腾速率均为正常氮正常水(ZZ)>低氮正常水(DZ)>正常氮干旱(ZG)>低氮干旱(DG),并且相对应处理下秦冠的以上指标均高于富士;正常供水下,缺氮处理使富士、 秦冠的根冠比比正常氮处理均有所增加,富士提高了2.05%,秦冠提高了22.40%。富士和秦冠的氮、 磷、 钾含量均表现出正常氮正常水(ZZ)>低氮正常水(DZ)>正常氮干旱(ZG)>低氮干旱(DG); 氮、 钾元素含量在植株各部位的分布顺序依次是叶>根>茎,磷元素则是根>叶>茎;光合氮素利用效率(PNUE)和氮素利用效率表现为秦冠处理之间差异极显著,富士处理之间差异不显著;秦冠的PNUE和NUE明显高于富士,在低氮正常水(DZ)处理下,秦冠氮肥利用率比富士高42.07%,在低氮干旱(DG)处理下高64.14%;低氮胁迫下富士和秦冠的NUE显著提高,并且秦冠提高的幅度高于富士。【结论】施用氮肥能够显著提高富士与秦冠的干物质量,同等水肥条件下,秦冠生长优于富士;水分亏缺会减少叶片对氮的吸收,干旱条件下适度增施氮肥,可提高果树的抗旱能力;低氮干旱胁迫下秦冠的生长指标、 光合指标及氮素利用效率指标均优于富士,表现出较强的抗低氮干旱胁迫的能力。  相似文献   

12.
Laser-induced breakdown spectroscopy (LIBS) is a new technique for the analysis of plant material. This study investigates the application of LIBS to pasture-based plant samples. The LIBS measurements were obtained from pelletized pasture samples (100 samples) that had been also analyzed by inductively coupled plasma–optical emission spectroscopy (ICP-OES) following microwave digestion for calibration and comparison purposes. Comparisons for elements sodium (Na), potassium (K), magnesium (Mg), calcium (Ca), manganese (Mn), iron (Fe), copper (Cu), zinc (Zn), boron (B), phosphorus (P), and sulfur (S) showed that LIBS could be used for almost all the standard profile total elements with concentrations down to low mg/kg levels (observed error of Na: 0.024 percent, K: 0.18 percent, Mg: 0.016 percent, Ca: 0.073 percent, P: 0.017 percent, Mn: 31 mg/kg, Fe: 150 mg/kg, Zn: 6.6 mg/kg, and B: 1.1 mg/kg). Elemental analysis at less than mg/kg levels was not possible using LIBS. The elements S and Cu were particularly difficult to analyze with reliability using LIBS at the concentration levels found in the plant samples. Replacing microwave digestion and subsequent ICP analysis with a direct analysis of dried plant samples using LIBS has the potential to improve the productivity and reduce the cost of testing.  相似文献   

13.
正The Center for Agricultural Resources Research(CARR),the Institute of Genetics and Developmental Biology(IGDB),Chinese Academy of Sciences,invites applicants for several research group leader positions.CARR is one of the research organizations in Chinese Academy of Sciences(CAS).We seek nominations and applications from individuals who have expertise and a record of accomplishment in research areas related to ecology,agro-hydrology,  相似文献   

14.
李聃枫  朱春梧 《土壤》2020,52(3):561-566
自20世纪60年代"绿色革命"以来,育种技术和农耕技术的发展促进了农作物产量的大幅提升,然而作物的营养品质出现下降趋势。在相似的遗传背景下,大气CO_2浓度升高会使单位体积农作物产品的营养元素含量下降,因此"绿色革命"至今,农作物产品的营养元素下降可能受大气CO_2浓度升高影响。通过植物生长箱模拟"绿色革命"初期和目前的大气CO_2浓度水平(310μmol/mol和400μmol/mol),针对主要C_3作物水稻、小麦和大豆,研究"绿色革命"以来大气CO_2浓度升高对其籽粒的C、N、Fe、Zn元素含量的影响,结果表明:CO_2浓度升高对3种作物籽粒的C元素含量几乎没有影响,变化幅度在±1.5%之间;籽粒的N、Fe、Zn元素含量普遍呈现下降趋势,但均未达到显著水平。  相似文献   

15.
Discovery and incorporation of genes from wild species provide means to sustain crop improvement, particularly when levels of resistance in the cultigens are low and virulent strains of pests and pathogens overcome the host plant resistance. The extent of utilization and the potential of the wild genepool for genetic enhancement were reviewed in five important food crops viz. sorghum, pearl millet, chickpea, pigeonpea and groundnut grown in the semi-arid tropics. Introgression from compatible wild germplasm in the primary gene pool resulted in transfer of new cytoplasmic male sterility systems in pearl millet and pigeonpea, development of high protein, cleistogamous flower and dwarf pigeonpea lines and foliar disease resistant groundnut cultivars. Utilization of wild species in secondary and tertiary gene pools has been generally limited due to sterility, restricted recombination or cross incompatibility. Nevertheless, these species are extremely important as they contain high levels of resistance to several important biotic and abiotic stresses. Several of them, like those belonging to the Parasorghum section and the rhizomatous Arachis species are sources of multiple resistances and hold great promise to sustain crop productivity.  相似文献   

16.
Staff members of the Department of Botany of Palacký University in Olomouc and Gene Bank Department – Workplace Olomouc, Research Institute of Crop Production in Prague, Czech Republic, conducted an expedition in seven European countries (Austria, Czech Republic, France, Germany, Italy, the Netherlands, Switzerland) in August/September 1999 to collect wild Lactuca spp. germplasm and study its geographic distribution, ecology and biodiversity. During the mission, more than 600 locations were visited resulting in the collection of 602 seed samples (accessions) of wild Lactuca species and 13 seed samples of related genera (Chondrilla and Mycelis). Lactuca serriola f. serriola, L. serriola f. integrifolia, L. saligna and L. viminea subsp. chondrilliflora were prevalent in southern Europe (Italy, France), however, only L. serriola was common in central and western Europe (Austria, Czech Republic, Germany, Netherlands, Switzerland). The greatest diversity of Lactuca species was found in France, where also the most seed samples (165) were collected. The most characteristic habitats with a high density of Lactuca spp. populations were observed along roads and highways, grassy ditches, ruderal communities, and dust-heaps. Natural infections by powdery mildew (Erysiphe cichoracearum) and downy mildew (Bremia lactucae) on some wild Lactuca spp. were observed. Recent observations concerning the geographic distribution, population structure, habitats, and natural occurrence of diseases of Lactuca spp. are discussed. This assemblage of genetic resources of Lactuca spp. can serve as the basis of future studies of species diversification, spatial population structure, plant microevolution, domestication processes, and genetic variability of host-parasite interactions.  相似文献   

17.
Biologically enhanced dissolution offers a method to speed removal of chlorinated solvent dense non-aqueous-phase liquid (DNAPL) sources such as tetrachloroethene (PCE) and trichoroethene (TCE) from aquifers. Bioremediation is accomplished by adding an electron donor to the source zone where fermentation to intermediates leading to acetic acid and hydrogen results. The hydrogen and possibly acetic acid are used by dehalogenating bacteria to convert PCE and TCE to ethene and hydrochloric acid. Reductive dehalogenation is thus an acid forming process, and sufficient alkalinity must be present to maintain a near neutral pH. The bicarbonate alkalinity required to maintain pH above 6.5 is a function of the electron donor: 800 mg/L of bicarbonate alkalinity is sufficient to achieve about 1.2 mM TCE dechlorination with glucose, 1.7 mM with lactate, and a much higher 3.3 mM with formate. Laboratory studies indicate that in mixed culture, formate can be used as an electron donor for complete conversion to ethene, contrary to pure cultures studies indicating it cannot. Various strategies can be used to add electron donor to an aquifer for DNAPL dehalogenation while minimizing pH problems and excessive electron donor usage, including use of injection-extraction wells, dual recirculation wells, and nested injection-extraction wells.  相似文献   

18.
The responses of tallgrass prairie plant communities and ecosystem processes to fire and grazing are well characterized. However, responses of invertebrate consumer groups, and particularly soil-dwelling organisms, to these disturbances are not well known. At Konza Prairie Biological Station, we sampled soil macroinvertebrates in 1994 and 1999 as part of a long-term experiment designed to examine the effects and interactions of annual fire, mowing, and fertilization (N and P) on prairie soil communities and processes. For nearly all taxa, in both years, responses were characterized by significant treatment interactions, but some general patterns were evident. Introduced European earthworms (Aporrectodea spp. and Octolasion spp.) were most abundant in plots where fire was excluded, and the proportion of the total earthworm community consisting of introduced earthworms was greater in unburned, unmowed, and fertilized plots. Nymphs of two Cicada genera were collected (Cicadetta spp. and Tibicen spp.). Cicadetta nymphs were more abundant in burned plots, but mowing reduced their abundance. Tibicen nymphs were collected almost exclusively from unburned plots. Treatment effects on herbivorous beetle larvae (Scarabaeidae, Elateridae, and Curculionidae) were variable, but nutrient additions (N or P) usually resulted in greater densities, whereas mowing usually resulted in lower densities. Our results suggest that departures from historical disturbance regimes (i.e. frequent fire and grazing) may render soils more susceptible to increased numbers of European earthworms, and that interactions between fire, aboveground biomass removal, and vegetation responses affect the structure and composition of invertebrate communities in tallgrass prairie soils.  相似文献   

19.
Abstract

A 3-year study was carried out to investigate quality parameters in 14 tree fruit and berry species grown in southern Norway. The species were blueberry, apple, aronia, sour cherry, sweet cherry, red raspberry, strawberry, blackcurrant, gooseberry, red currant and elderberry, harvested along with wild bilberry, cloudberry and lingonberry. Significant differences between species were identified for all quality parameters. The coefficient of variation between species was lowest for pH (12.5%), dry matter (18.9%) and soluble solids (25.3%), followed by titratable acids (59.3%), total phenolics (83.8%), antioxidant capacity FRAP (85.7%) and antiradical power by the DPPH-assay (97.8%), total monomeric anthocyanins (132%) and ascorbic acid (137%). Average coefficient of variation within species were lower and ranged from 4 (pH) to 62% (ascorbic acid). Only the FRAP values were significantly affected by harvesting year with lower levels in 2004 than in 2005 and 2006. There were significant interactions between species and harvesting year for dry matter, soluble solids, pH, ascorbic acid and FRAP. The results indicate generic ranges in composition within species independent upon growing location and climate, and the composition of the tree fruits and berries is not likely to deviate from these ranges. It is concluded that desirable composition of tree fruits and berries and their products should primarily be achieved by selection among species rather than searching fors broadened variation within individual species.  相似文献   

20.
正The Center for Agricultural Resources Research(CARR),the Institute of Genetics and Developmental Biology(IGDB),Chinese Academy of Sciences,invites applicants for several research group leader positions.CARR is one of the research organizations in Chinese Academy of Sciences(CAS).We seek nominations and applications  相似文献   

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