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Information Processing in Agriculture 2019年第2期6卷 224-232页

作者： Tingting Qian Xiuguo Zheng Xinyu Guo Weiliang Wen Juan Yang shenglian lu Shanghai Academy of Agriculture Sciences Shanghai 201403China College of Computer Science and Information Technology Guangxi Normal UniversityGuilin 541004China Beijing Key Lab of Digital Plant Beijing 100097China Shanghai Technology Engineering Research Center for Digital Agriculture Shanghai 201403China

Accurate structural phenotyping analysis is essential to understand plant architectural adaptation strategy to environment *** aim of this study was to analyze leaf arrangement and geometry influenced by azimuthally generated light gradient;and to simulate static and heterogeneous cucumber canopies using regression equations by considering more geometric *** continuous measurements of structural organ parameters were obtained to fit the organ initiation and expansion *** measurements with three density treatments were obtained to validate model *** describe leaf distribution and orientation characteristics in more detail,azimuth and elevation models were introduced into canopy structure *** distribution frequency was simulated based on leaf area index and solar elevation angle while leaf elevation was simulated based on leaf azimuth and acropetal phytomer *** study provides an important basis for structural phenotyping analysis of cucumber canopy,which is essential for more accurate functional-structural modelling in the future.

关键词： Phenotyping Structure Heterogeneity Model calibration Azimuth Elevation

A novel method for extracting skeleton of fruit treefrom 3D point clouds

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International Journal of Modeling, Simulation, and Scientific Computing 2020年第6期11卷 78-89页

作者： shenglian lu Guo Li Jian Wang College of Computer Science and Information Technology Guangxi Normal University Guilin 541004P.R.China Guangxi Key Lab of Multi-Source Information Mining and Security No.15 Yucai Road Guilin 541004P.R.China Center of Information Technology Beijing Municipal Bureau of Agriculture and Rural Affairs No.6 Yumin Middle Rood Beijing 100029P.R.China

Tree skeleton could be useful to agronomy researchers because the skeleton describes the shape and topological structure of a *** phenomenon of organs’mutual occlusion in fruit tree canopy is usually very serious,this should result in a large amount of data missing in directed laser scanning 3D point clouds from a fruit ***,traditional approaches can be ineffective and problematic in extracting the tree skeleton correctly when the tree point clouds contain occlusions and missing *** overcome this limitation,we present a method for accurate and fast extracting the skeleton of fruit tree from laser scanner measured 3D point *** proposed method selects the start point and endpoint of a branch from the point clouds by user’s manual interaction,then a backward searching is used to find a path from the 3D point cloud with a radius parameter as a *** experimental results in several kinds of fruit trees demonstrate that our method can extract the skeleton of a leafy fruit tree with highly accuracy.

关键词： Skeleton extraction fruit tree 3D point cloud modeling plant structure

An Algorithm for Segmenting Spots in Crop Leaf Disease Image with Complicated Background

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An Algorithm for Segmenting Spots in Crop Leaf Disease Image...

作者： Zhihua Diao Xinyu Guo Chunjiang Zhao shenglian lu Weiliang Wen National Engineering Research Center for Information Technology in Agriculture Department of Automation University of Science and Technology of China

A segmentation algorithm is proposed in this paper to deal with the problem of segmenting spots from crop leaf disease image with complicated *** the profile of the initial image is extracted by using a watershed algorithm from the gray-scale image,and the binary image is obtained by combining a threshold processing and morphological *** the accurate leaf disease image is extracted by using window clipping and image ***,the spots are segmented from the leaf disease image by using green segmentation algorithm,and the accurate spot information can be obtained after noise *** experimental result shows that the proposed algorithm can be used in complicated field environment with high extracting accuracy.

关键词： Image Segmenting Watershed Algorithm Morphological Processing Noise Elimination Complicated Background

STUDY ON MAIZE LEAF MORPHOLOGICAL MODELING AND MESH SIMPLIFICATION OF SURFACE

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STUDY ON MAIZE LEAF MORPHOLOGICAL MODELING AND MESH SIMPLIFI...

Computer and Computing Technologies in Agriculture——First IFIP TC 12 International Conference(CCTA2007) Volume I

作者： Xinyu Guo Chunjiang Zhao Boxiang Xiao shenglian lu Changfeng Li National Research Center for Information Technology in Agriculture Institute of computer technology Dalian University of Technology

According to the need of canopy visualization calculation in the digital plant research,we introduced a method,using Non-Uniform Rational B-Splines（NURBS） interpolation and multi-line segment splitting algorithm,to reconstruct the 3D morphological structure of maize leaf with a complexity controllable *** the data cloud obtained by digitizer,construct the surface of maize leaf by calculating the knot vectors and reverse calculating surface control points by difference *** final visualization effect is *** to leaf morphological characteristics,leaf surface mesh can be simplified by using inverse calculation of multi-line segment splitting algorithm,and the surface main characteristics can be maintained *** method can be used in canopy visualization calculation and light distribution *** showed that it can improve the calculation efficiency obviously without increase the calculation error.

关键词： maize leaf NURBS geometric modeling mesh simplification light distribution calculation

Fast Modeling System of Digital Plant for Virtual Education

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Fast Modeling System of Digital Plant for Virtual Education

2013教育技术与信息系统国际会议

作者： Boxiang Xiao Xinyu Guo Jianjun Du shenglian lu Xiaodong Guo Beijing Research Center for Information Technology in Agriculture

Virtual education is widely used in many fields including agricultural training and popular science. Modeling technologies and software tools for content making of virtual educations about digital plant is shortages and it is an obvious limitation of relevant applications. We present a fast modeling technology and developed a system of digital plant for virtual education. The method depends on real geometric data of plant collected by three-dimensional device, and a template-based modeling algorithm is employed for rapidly reconstruction of complex plant organs. The system consists of several modules including data processing, knowledge management, geometric modeling, graphics support and user interface. The system supports users to make education content about digital plant. Finally, some typical applications are given and some future works are discussed.

关键词： Virtual Education Digital Plant Modeling system

Evaluating the Effect of Multiple Scattering on Interception of Photosynthetically Active Radiation at Organ Scale Within Maize Canopy

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Evaluating the Effect of Multiple Scattering on Interception...

作者： Jun Meng Xinyu Guo Xiaohong Du Weiliang Wen shenglian lu Boxiang Xiao China National Engineering Research Center for Information Technology in Agriculture(NERCITA) Life Science Department of luoyang Normal University

Multiple scattering is a critical factor that affects the spatial distribution of photosynthetically active radiation(PAR) within the *** it is neglected sometimes to reduce the numerical complexity in plant functioning simulation with no adequate *** this study,using VisuAlea visual programming tool and Caribu module which based on the nested radiosity method,PAR interception at organ scale is analyzed on the basis of 3-dimentional architecture model of maize canopy which consists of 50 *** with photosynthesis model,the importance of multiple scattering to canopy PAR distribution is *** result shows that,the multiple scattering take notable effect on PAR intensity on leaf surface(|t|> t),especially the lower surface,and lead to a 19.88%enhancement of absorbed *** to the high light usage ratio when PAR far below the saturation point,leaves under multiple scattering conditions show an average of 7.48 μmol CO · m· sphotosynthesis rate,23.43%more than control’s 6.06 μmol CO·m·*** leaves in the lower layers of the canopy can not receive as much scattering as those in the upper layers,their resultant photosynthesis promotion almost *** a conclusion,the multiple scattering affect spatial distribution of PAR within the canopy significantly,and the multiple scattering process should be considered with special attention in crop growth simulation,especially in agronomical view.

关键词： The Nested Radiosity Model Multiple Scattering Spatial Distribution Canopy Photosynthetically Active Radiation

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融合生理因子的植物叶片表观建模

计算机辅助设计与图形学学报 2014年第4期26卷 597-608页

作者：赵春江苗腾郭新宇陆声链北京农业信息技术研究中心农业部农业信息技术重点开放实验室北京100097

植物叶片具有复杂的内部结构、生理过程和光学特性,使得在计算机上准确模拟叶片的表观十分困难.为此提出一种基于生理因子的植物叶片表观材质模型.首先考虑单双子叶植物在结构上的差别,利用单N层板和双N层板抽象叶片内部结构;然后基于PR... 详细信息

植物叶片具有复杂的内部结构、生理过程和光学特性,使得在计算机上准确模拟叶片的表观十分困难.为此提出一种基于生理因子的植物叶片表观材质模型.首先考虑单双子叶植物在结构上的差别,利用单N层板和双N层板抽象叶片内部结构;然后基于PROSEPCT模型推导得到叶片材质模型的漫反射和透射项,并采用CookTorrance模型作为高光反射项,形成BRDF+BTDF形式的参数化材质模型;最后采用一种叶色变化算法将模型扩展为时间-空间变化的叶片参数化材质模型.实验结果表明,该模型可以通过控制叶绿素、胡萝卜素和叶片结构参数等生理因子来实时地调整叶片的表观,实现空间变化、时间变化的叶片老化模拟,具有较好的真实感效果和绘制速度,能够满足实时交互的需要.

关键词：自然现象模拟叶片表观建模真实感绘制叶片散射模型

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三维植物叶片萎蔫变化实时模拟

计算机辅助设计与图形学学报 2013年第11期25卷 1643-1650页

作者：唐勇曹园园陆声链郭新宇燕山大学信息科学与工程学院秦皇岛066004 燕山大学河北省计算机虚拟技术与系统集成重点实验室秦皇岛066004 北京农业信息技术研究中心北京100097

为了真实模拟在缺水、高温等条件下植物叶片的萎蔫变形过程,结合植物叶片生理特征和物理特征,采用改进的单层质点-弹簧结构实时模拟了植物叶片萎蔫变形,较好地实现多种具有不同叶脉结构的植物叶片在三维空间中的动态萎蔫变形过程.首先... 详细信息

为了真实模拟在缺水、高温等条件下植物叶片的萎蔫变形过程,结合植物叶片生理特征和物理特征,采用改进的单层质点-弹簧结构实时模拟了植物叶片萎蔫变形,较好地实现多种具有不同叶脉结构的植物叶片在三维空间中的动态萎蔫变形过程.首先从真实植物叶片的数字图像中提取叶片的边缘轮廓和叶脉,并在此基础上建立叶片的曲面网格模型;然后通过叶片曲面网格建立叶片的质点-弹簧变形模型,考虑到叶肉和叶脉结构在植物叶片萎蔫变形中具有不同的作用,将质点-弹簧模型中的质点分为叶脉质点、叶缘特征点和普通质点3类,同时设置不同的受力约束使不同类型的质点具有不同的运动方式;最后对叶脉位置上的弹簧和其他弹簧设置不同的收缩强度,以突出叶脉对叶片形变的主导作用.实验结果表明,该方法能够较好地模拟不同形态结构的植物叶片的萎蔫变形过程,满足实时交互的需要.

关键词：植物叶片形态建模 Delaunay三角化物理模拟质点-弹簧模型叶片变形

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植物叶片萎蔫过程的物理表示方法

农业机械学报 2014年第5期45卷 253-258页

作者：苗腾郭新宇温维亮陆声链沈阳农业大学信息与电气工程学院沈阳110866 北京农业信息技术研究中心农业部农业信息技术重点开放实验室北京100097

为定量化描述植物叶片萎蔫的动态过程,提出一种基于物理模型的描述方法。首先基于植物叶片的三维模型构造体素结构用以抽象植物的细胞结构,在此基础上利用质点弹簧模型表示细胞之间的受力关系,然后根据欧拉-拉格朗日方程描述细胞的运动... 详细信息

为定量化描述植物叶片萎蔫的动态过程,提出一种基于物理模型的描述方法。首先基于植物叶片的三维模型构造体素结构用以抽象植物的细胞结构,在此基础上利用质点弹簧模型表示细胞之间的受力关系,然后根据欧拉-拉格朗日方程描述细胞的运动过程,最后采用隐式纽马克积分法对方程求解进而得到细胞的三维位置变化。以萎蔫状态下叶尖在几何空间的变化轨迹作为参考属性进行数据验证,模拟的叶尖运动方向与实测值相差19°,实测的叶尖三维空间位置与模拟结果的距离差值在0.68 cm至3.0 cm之间,数据表明所提算法得到的叶尖变化轨迹与真实叶尖变化轨迹接近;其次,从视觉角度评价,也可逼真地模拟萎蔫状态下叶片三维形态的变化过程。

关键词：植物叶片萎蔫过程计算机模拟物理建模

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基于点云数据的植物叶片曲面重构方法

农业工程学报 2012年第3期28卷 184-190页

作者：孙智慧陆声链郭新宇温维亮北京农业信息技术研究中心北京100097 首都师范大学信息工程学院北京100048

叶子是植物最重要的器官之一,建立植物叶片的高精度曲面模型对于开展植物叶片形态特征分析和冠层光分布计算等研究具有重要意义。该文提出了一种基于点云数据的植物叶片曲面重构方法,该方法首先对原始点云数据进行噪声点剔除和数据精简... 详细信息

叶子是植物最重要的器官之一,建立植物叶片的高精度曲面模型对于开展植物叶片形态特征分析和冠层光分布计算等研究具有重要意义。该文提出了一种基于点云数据的植物叶片曲面重构方法,该方法首先对原始点云数据进行噪声点剔除和数据精简,然后采用Delaunay三角剖分方法生成初始网格曲面,再对网格曲面进行优化处理。结果表明该方法能够基于激光扫描三维点云数据快速重构出植物叶片的高精度网格曲面,包括萎蔫和枯萎等复杂形态。该研究可为植物建模与可视化相关研究提供参考。

关键词：植物重建模型最小二乘平面网格点云