Modified gray level difference-based thresholding segmentation and its application in X-Ray welding image

Thresholding is a popular image segmentation method that often requires as a preliminary and indispensable stage in the computer aided image process, particularly in the analysis of X-ray welding images. In this paper, a modified gray level difference-based transition region extraction and thresholding algorithm is presented for segmentation of the images that have been corrupted by intensity inhomogeneities or noise. Classical gray level difference algorithm is improved by selective output of the result of the maximum or the minimum of the gray level with the pixels in the surrounding, and multi-structuring of neighborhood window is used to represent the essence of transition region. The proposed algorithm could robustly measure the gray level changes, and accurately extract transition region of an image. Comparisons with other approaches demonstrate the superior performance of the proposed algorithm.     

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供应商选择问题是物流领域内的一个重要问题，其目标函数就是在包括送达时间、原料质量和服务水平等的约束下使总花费最小。传统的确定性模型取得了较好的效果，但是由于其约束条件的随机性和模糊性，需要应用不确定性模型来更准确地描述和给出最优解。论文应用了不确定性模型描述这类供应商选择问题，这个不确定性模型就是一类特殊的机会约束规划模型，此类机会约束可以转化为相应的等价类，这样不确定性模型就可以转化为确定性模型，然后设计了解决这类问题的遗传算法。通过实例计算表明，不确定性优化模型及遗传算是解决供应商选择等这类不确定性智能商业问题的有效办法，有广泛的应用前景。     

IMAGE SEGMENTATION BASED ON MARKOV RANDOM FIELD AND WATERSHED TECHNIQUES

IntroductionThere are many methods to perform imagesegmentation and edge detection tasks that incor-porate region- growing and edge detection tech-niques,for example,it is applying edge detectiontechniques to obtain Difference In Strength( DIS)map then employ region growing techniques towork on the map as in Refs.[1 ,2 ]. In the others,combining both special and intensity information inimage segmentation approach based on multi- reso-lution edge detection,region selection and intensi-ty thre…     

MEDICAL IMAGE SEGMENTATION BASED ON A MODIFIED LEVEL SET ALGORITHM

Imagesegmentationplaysanimportantrolein imageanalysisaswellasinhigh levelimageinter pretationandunderstandingsuchasrobotvision, objectrecognition,andmedicalimaging.Numerous segmentationmethodshavebeendeveloped.How ever,medicalimagesareoftencorruptedbyno…     

基于云模型的模糊边缘检测

基于云模型和模糊集理论。提出了一种新的边缘检测方法．该方法根据图像灰度。借助区域生长算法产生对象云；通过云运算生成边界云并构建模糊隶属带。进而在条件概率和模糊划分熵的基础上。根据最大模糊熵原则确定最优阈值，对图像模糊边界进行提取．试验结果表明。该算法能保留大量低灰度信息。可以获得较好的枪涮特栗．     

FULLY AUTOMATIC FRAMEWORK FOR SEGMENTATION OF BRAIN MRI IMAGE

Automaticbraintissuesegmentationfrommag neticresonanceimages(MRI)isofgreatimportance forresearchandclinicalstudyofmuchneurological pathology.Duringthepastdecade,theMRIhashad agreatimpactonthediagnosticimagingofmosthu manorgansystem.Thesegmentationofbrai…     

考虑运营费用和线性化树形改编策略的货物列车开行方案研究

国外货物列车开行方案的制定通常以车流和车列的综合费用最小为目标,而我国大多以车流的集结和改编车小时消耗最小为目标,很少考虑每个车列的运营费用,造成理论开行费用偏小,其方案未必最优.此外,我国现有开行方案模型将车流树形改编策略递归表示,不利于对不可行流的处理.鉴于此,本文对现有模型进行改造,在总目标中增加车列运营费用;在约束中引入新的决策变量,实现线性化的车流树形改编策略.设计并行禁忌搜索算法实现对模型的求解.结果表明,单位列车运营费用中的固定费用对开行方案有着重要的影响,其费用越高,总开行列数越少,列车平均运距越长,但总改编车流量增加;线性化的改编策略直观展现车流的改编路径,便于对不可行流的运输方案进行调整.     

SET OPERATOR-BASED METHOD OF DENOISING MEDICAL VOLUME DATA

Ｖｏｌｕｍｅｒｅｎｄｅｒｉｎｇ[1,2 ] ｉｓａｐｏｗｅｒｆｕｌｖｉｓｕａｌｉｚａ ｔｉｏｎｔｏｏｌｅｓｐｅｃｉａｌｌｙｕｓｅｆｕｌｉｎｍｅｄｉｃａｌａｐｐｌｉｃａｔｉｏｎｓ .Ｉｔｅｎａｂｌｅｓｔｈｅｄｉｓｐｌａｙｏｆａｎａｔｏｍｉｃａｌｓｔｒｕｃｔｕｒｅｓｉｎａｓｐａ ｔｉａｌｃｏｎｔｅｘｔｗｉｔｈｔｈｅｓｕｒｒｏｕｎｄｉｎｇａｎａｔｏｍｙ ,ｄｉｒｅｃｔｌｙｆｒｏｍａｆｉｅｌｄｏｆｉｍａｇｅｄａｔａ .Ｔｈｉｓｔｅｃｈｎｉｑｕｅｈａｓｂｅｅｎａｐｐｌｉｅｄａｔｓｅｖｅｒａｌａｎａｔｏｍｉｃｓｉｔｅｓａ…     

多目标最短路径模型及算法

为获得满足决策者需要的多目标最短路径问题的有效路径,建立了多目标最短路径模型,并提出了综合k-最短路径算法和多目标格序决策方法的多项式算法.该算法根据决策者可以接受的各单目标的上限,用k-最短路径算法,分别确定各单目标的可行路径集及其交集.再用多目标格序决策方法,比较交集中的有效路径,最终获得决策者满意的路径.     

A new algorithm to automatically extract the drainage networks and catchments based on triangulation irregular network digital elevation model

A new algorithm to automatically extract drainage networks and catchments based on triangula- tion irregular networks （TINs） digital elevation model （DEM） was developed. The flow direction in this approach is determined by computing the spatial gradient of triangle and triangle edges. Outflow edge was defined by comparing the contribution area that is separated by the steepest descent of the triangle. Local channels were then tracked to build drainage networks. Both triangle edges and facets were considered to con- struct flow path. The algorithm has been tested in the site for Hawaiian Island of Kaho＇olawe, and the results were compared with those calculated by ARCGIS as well as terrain map. The reported algorithm has been proved to be a reliable approach with high efficiency to generate well-connected and coherent drainage networks.     

基于帧缓存的多角度影像精细纹理映射方法

三维建筑物模型纹理映射方法通常针对单独平面选取单一影像投影,然而单张关联影像通常存在部分遮挡问题,影响纹理映射质量. 为此,本文提出一种基于帧缓存纹理绘制技术的多角度影像精准纹理映射方法. 首先将单体化精细建筑模型和倾斜摄影测量解决方案生成的三角网模型配准,再根据建筑模型空间特征进行纹理绘制基元提取;然后根据纹理绘制基元对三角网模型生成虚拟渲染相机,利用帧缓存纹理绘制方法,获取帧缓存对象并提取纹理,最后通过纹理绘制基元映射到精细建筑物模型表面,实现三角网模型到精细单体化建筑模型的自动纹理映射. 利用倾斜摄影测量数据进行实验,实验结果表明,相比传统方法,本文方法减少了14%以上的不良纹理比率,纹理空间压缩率达到14.21%,且具有更精确的纹理映射效果,能满足精细建筑模型的纹理重建需求.      

DESIGN OF A NEW INTERPOLATED CONTROLLER FOR STABILIZATION OF A SET OF INTERPOLATED PLANTS

IntroductionDynamics of almost all plants in reality variesaccording to the condition under which the plantis operated.An idea to describe the variation ofplant dynamics is interpolating a number of rep-resentative models defined at representative op-erating points.In Ref. [1 ] ,the plant was as-sumed to described as a linear interpolation ofproper stable coprime factorizations of transferfunctions of two representative models and thestabilization problems have been considered. InRef.[2 ] ,it…     

DIRECT VOXEL-PROJECTION FOR VOLUMETRIC DATA RENDERING IN MEDICAL IMAGERY

IntroductionWith the development of medical imagingtechniques,many devices such as computed tomo-graphy,positron emission tomography,singlephoton emissioin computed tomography,magneticresonance imaging,and ultrasound scanners arewidely available for capturing the planar images ofhuman organs directly in machine- readable form.These medical imaging methods bring a lot of ad-vantages to clinical diagnosis and treatment.How-ever,due to these systems'2 - D imaging modali-ties,it is difficult to un…     

IMAGE ANALYSIS BASED ON EDGE DETECTION TECHNIQUES

IntroductionEdges are pixels where brightness changesabruptly and often used in image analysis for find-ing region boundaries.It locates sharp changes inthe intensity function.Edges detection is basic im-age features.They carry useful information aboutobject boundaries.Edges can be used for object i-dentification,image analysis and image filteringapplications as well.We shall consider as an edgethe border between two homogeneous image re-gions having different illumination.This definitionimp…     

灰色系统方法在公路工程评标中的应用

针对公路工程招标工作,考虑把评标工作看作是对多个可选的投标单位进行综合评价的问题,通过综合评价排定投标单位的优劣顺序,最终选择出最优的投标单位。结合评标过程中某些指标很难用准确的定量描述而表现出的信息灰色这一特点,运用了灰色系统方法来对多个投标单位进行灰色评价,并用综合权值排序方法进行排序,选出最优投标单位。     

地表模型上的最短路径算法研究

提出了一种基于空间三角网格的地表模型上的最短路径算法。该算法利用离散点的空间信息计算得到起点So到周围邻接点的最短距离,然后用逐步向外层边界扩展的方法扩大起点的邻接点范围,直到起点的邻接点中包含终点to。此过程可求得So到to的最短路径上的关键点,然后求取无原始边连接的2个关键点之间的精确路径点。     

超对策模型中结局偏好模糊认知信息的融合

提出了一种新的超对策结局偏好模糊认知信息的融合方法.用一种模糊集结算子来表示专家群体对其他局中人结局偏好的模糊认知,通过求解线性规划模型得到结局偏好群体模糊认知的水平截集;以与模糊数的截集相关的解模糊函数和Newton-Cotes积分公式,得到专家群体对其他局中人结局偏好清晰认知的关系矩阵;运用大多数一致性优胜者模糊集来确定其他局中人的结局偏好向量.给出的数值例子说明了文中提出方法的有效性.     

Surface reconstruction by structured light projection

A rapid and practical method is proposed to reconstruct surface based on the linked structured light stripes which are produced by structured light projection. The subpixel points on a stripe are linked firstly one by one to form a stripe ensemble which is then transformed to a point ensemble in 3D space. The initial mesh with local optimization is generated by triangulating each two adjacent point ensembles. In order to obtain a better mesh, our improved edge flipping algorithm is employed to optimize the initial mesh globally. Because of employing the information of the linked structured stripes, our reconstruction algorithm is performed fastly. Moreover, the subpixel points on each stripe are already linked on the captured images such that they do not require the high sampling density. The experiments show that the proposed method constructs a surface rapidly and effectively.     

A FAST ALGORITHM FOR EXTREME FILTER OF 2D IMAGE

ＡＦＡＳＴＡＬＧＯＲＩＴＨＭＦＯＲＥＸＴＲＥＭＥＦＩＬＴＥＲＯＦ２ＤＩＭＡＧＥＸｕＬｅｉ（许磊）ＬｉＪｉｅｇｕ（李介谷）ＬｉＷｅｎｓｈｕｎ（李文舜）（ＩｎｓｔｉｔｕｔｅｏｆＰａｔｅｒｎＲｅｃｏｇｎｉｔｉｏｎ＆ＩｍａｇｅＰｒｏｃｅｓｓｉｎｇ，Ｓｈａｎｇ...     

一种Delaunay三角网数模快速定位算法

逐点插入法是构建Delaunay三角网的主流算法之一，在众多三角形中快速定位目标三角形是影响逐点插入法构网速度的一个重要因素，同时也是影响高程内插速度的关键。在分析多种已有定位法特点的基础上提出区域定位法，给出了详细的判断条件，并加以证明。通过对几种定位方法进行分析比较，在两种投点方式下用逐点插入法对四种算法进行了TIN的构网实验，结果表明均匀投点的构网速度都要快于任意投点的构网速度，区域定位法搜索方向唯一，算法稳健，具有较快的定位速度。