改进的判别割及其在图像分割中的应用

谱聚类算法能在任意形状的样本空间上聚类且收敛于全局最优解,但判别割(Dcut)算法在计算正则化相似度矩阵及其特征向量时比较耗时,而基于子空间的Dcut(SDcut)算法则不稳定,为此,提出基于主成分分析(PCA)的Dcut算法(PCA-Dcut)。PCA-Dcut算法采用PCA算法计算相似度矩阵的前m个大的特征值对应的特征向量构造一个新的矩阵,然后采用构造的矩阵与相似度矩阵和拉普拉斯矩阵分别进行矩阵运算;接着通过计算获得一个m阶正则化相似度矩阵,并计算该矩阵的k个最大特征向量;最后使用构造的矩阵与这k个特征向量相乘获得最终用于分类的特征向量。PCA-Dcut算法能降低Dcut算法的计算复杂度。通过对人工合成数据集、UCI数据集和真实图像的仿真实验表明,PCA-Dcut算法的聚类准确率与Dcut等谱聚类算法相当,同时在分割图像时的运算速度约为Dcut的5.4倍,并具有比SDcut更快的速度和更好的性能。     

ITK及其在医学图像分割中的应用

ITK(The Insight Toolkit)是一个开放的、面向对象的类库.它提供了强大的二维医学图像处理功能,主要用于医学图像的预处理、分割及配准.本文主要介绍图像分割的算法以及ITK在图像分割中的应用,并简要介绍一个基于ITK的医学图像处理的实现.     

A modified support vector machine and its application to image segmentation

Recently, researchers are focusing more on the study of support vector machine (SVM) due to its useful applications in a number of areas, such as pattern recognition, multimedia, image processing and bioinformatics. One of the main research issues is how to improve the efficiency of the original SVM model, while preventing any deterioration of the classification performance of the model. In this paper, we propose a modified SVM based on the properties of support vectors and a pruning strategy to preserve support vectors, while eliminating redundant training vectors at the same time. The experiments on real images show that (1) our proposed approach can reduce the number of input training vectors, while preserving the support vectors, which leads to a significant reduction in the computational cost while attaining similar levels of accuracy. (2)The approach also works well when applied to image segmentation.     

Simplified parameters model of PCNN and its application to image segmentation

Pulse-coupled neural network (PCNN), which simulates the synchronous oscillation phenomenon in the visual cortex of small mammals, has become a useful model for image processing. In the model, several parameters were usually required to properly set for adjusting the behavior of neurons. However, undesired behavior may occur owing to inappropriate parameters setting. To alleviate this problem, we propose to simplify some parameters of PCNN, and apply it into image segmentation. First, exponential delay factors are abandoned for adjusting the neuron input, and the neural input is then associated with image information as well as pulse output. In addition, neural threshold inherent in PCNN is simplified as an adaptive threshold related to image properties, allowing our model to easily alter the behavior of neurons. Particularly, the characteristic of synchronous pulse is thereby kept by introducing a fuzzy clustering method, instead of linking coefficient for grouping pixels with similarity and spatial proximity through iterative computation. Experimental results on synthetic and real infrared images show that the proposed model has high performance of segmentation. Furthermore, our model has better adaptability for segmenting real-world images when compared with several existing PCNN-based methods and some classic segmentation methods.     

活动轮廓的演化控制及其在铁谱图像分割中的应用

为了提高活动轮廓(active contour,AC)对边缘特征局部极小值的搜索效率,从而提高其对铁谱图像的分割速度,提出了一种基于活动轮廓评价和演化行为控制的图像分割方法.首先,设计了一种基于矢量图的边缘指示函数(edge indicator,EI)的计算方法,相应的计算结果为活动轮廓模型建立了一个边缘指向更加明确的边缘指示场(edge indicator field,EIF).其次,设计了曲线EI值的无迹卡尔曼滤波模型,并基于此提出了活动轮廓边缘特征的跟踪和评价方法.最后,根据以上评价结果调整曲线模型的参数以控制其演化行为.这种参数调节机制保证了曲线模型参数在不同的区域具有不同的参数设置.试验结果表明,该算法显著地提高了控制演化过程的灵活性以及活动轮廓的收敛速度,并且它能够实现对各种形状磨粒的准确分割,不仅避免了弱边界区域的泄漏现象,而且能够有效滤除背景中的各种噪声干扰和非磨粒目标.     

Shape "break-and-repair" strategy and its application to automated medical image segmentation

In three-dimensional medical imaging, segmentation of specific anatomy structure is often a preprocessing step for computer-aided detection/diagnosis (CAD) purposes, and its performance has a significant impact on diagnosis of diseases as well as objective quantitative assessment of therapeutic efficacy. However, the existence of various diseases, image noise or artifacts, and individual anatomical variety generally impose a challenge for accurate segmentation of specific structures. To address these problems, a shape analysis strategy termed "break-and-repair" is presented in this study to facilitate automated medical image segmentation. Similar to surface approximation using a limited number of control points, the basic idea is to remove problematic regions and then estimate a smooth and complete surface shape by representing the remaining regions with high fidelity as an implicit function. The innovation of this shape analysis strategy is the capability of solving challenging medical image segmentation problems in a unified framework, regardless of the variability of anatomical structures in question. In our implementation, principal curvature analysis is used to identify and remove the problematic regions and radial basis function (RBF) based implicit surface fitting is used to achieve a closed (or complete) surface boundary. The feasibility and performance of this strategy are demonstrated by applying it to automated segmentation of two completely different anatomical structures depicted on CT examinations, namely human lungs and pulmonary nodules. Our quantitative experiments on a large number of clinical CT examinations collected from different sources demonstrate the accuracy, robustness, and generality of the shape "break-and-repair" strategy in medical image segmentation.     

改进主动轮廓线模型在图像分割中的应用

主动轮廓线模型(Active Contour Model,ACM),也称作蛇(Snake)模型,是一种常用的图像分割算法。在基于主动轮廓线的图像分割中,深度凹陷边界的逼近和弱边界区域的分割一直是一个难点。引入了一种局部纹理模型(Local Profile Model)匹配算法,通过匹配沿控制点法线方向像素和局部纹理模型可以确定弱边界区域的真实边界,并结合一种新的计算控制点曲率外力的算法,使得主动轮廓线模型能够逼近图像的深度凹陷区域的同时提高算法的收敛速度。实验结果表明,该方法是有效的。     

A class of discrete multiresolution random fields and its application to image segmentation

In this paper, a class of Random Field model, defined on a multiresolution array is used in the segmentation of gray level and textured images. The novel feature of one form of the model is that it is able to segment images containing unknown numbers of regions, where there may be significant variation of properties within each region. The estimation algorithms used are stochastic, but because of the multiresolution representation, are fast computationally, requiring only a few iterations per pixel to converge to accurate results, with error rates of 1-2 percent across a range of image structures and textures. The addition of a simple boundary process gives accurate results even at low resolutions, and consequently at very low computational cost.     

一种新的MLBP-Otsu算法及在舌裂纹分割中的应用

中医舌诊中只有精确、完整地分割出舌裂纹,才能准确地对舌裂纹信息进行定量化的特征表示与描述,而目前少有方法能达到此要求。为此,提出了一种新颖的基于改进的局部二值模式（Local Binary Pattern,LBP）算子与Otsu阈值分割技术相结合的舌裂纹分割算法（MLBP-Ostu算法）。根据舌裂纹的纹理特征对传统LBP的模式分类方法进行重定义;引入一个粗糙度度量因子[R],如某区域的[R]值偏小或偏大,则把其归类为非裂纹区,不进行LBP特征值计算;利用Otsu方法对前面得到的LBP特征图进行阈值分割,从而得到舌裂纹的二值图像。实验结果表明,该算法能较精确、完整地分割出舌裂纹,并且不需要预先分割出舌体区域,为将来舌诊的定量化研究及临床应用提供了有效手段。     

Striped-texture image segmentation with application to multimedia security

In today’s rapid growth of volume of multimedia data, security is important yet challenging problem in multimedia applications. Image, which covers the highest percentage of the multimedia data, it is very important for multimedia security. Image segmentation is utilized as a fundamental preprocessing of various multimedia applications such as surveillance for security by breaking a given image into multiple salient regions. In this paper, we present a new image segmentation approach based on frequency-domain filtering for images with stripe texture, and generalize it to lattice fence images. Our method significantly reduces the impact of stripes on segmentation performance. The approach proposed in this paper consists of three phases. Given the images, we weaken the effect of stripe texture by filtering in the frequency domain automatically. Then, structure-preserving image smoothing is employed to remove texture details and extract the main image structures. Last, we use an effective threshold method to produce segmentation results. Our method achieves very promising results for the test image dataset and could benefit a number of new multimedia applications such as public security.

     

改进CV模型的医学图像分割

基于水平集的图像分割方法能有效处理拓扑结构较复杂、有分支的目标,分割结果对目标初始轮廓的位置不敏感,对图像中对比度低的边界的识别效果不佳。广义模糊算子能有效提高图像边界区域与非边界区域的对比度,图像细节分明、失真度小。运用广义模糊算子来改进水平集分割方法中的Chan-Vese模型（简称CV模型）的速度函数;并扩大传统CV模型的边界检测范围以减少迭代次数,加快收敛速度;最后消除误分割区域以进一步提高分割的准确性。对模拟和真实医学图像分割的实验结果表明：改进后的模型能较大提高分割的准确性及效率。     

A reductive approach to hypergraph clustering: An application to image segmentation

In the last few years, hypergraph-based methods have gained considerable attention in the resolution of real-world clustering problems, since such a mode of representation can handle higher-order relationships between elements compared to the standard graph theory. The most popular and promising approach to hypergraph clustering arises from concepts in spectral hypergraph theory [53], and clustering is configured as a hypergraph cut problem where an appropriate objective function has to be optimized. The spectral relaxation of this optimization problem allows to get a clustering that is close to the optimum, but this approach generally suffers from its high computational demands, especially in real-world problems where the size of the data involved in their resolution becomes too large. A natural way to overcome this limitation is to operate a reduction of the hypergraph, where spectral clustering should be applied over a hypergraph of smaller size. In this paper, we introduce two novel hypergraph reduction algorithms that are able to maintain the hypergraph structure as accurate as possible. These algorithms allowed us to design a new approach devoted to hypergraph clustering, based on the multilevel paradigm that operates in three steps: (i) hypergraph reduction; (ii) initial spectral clustering of the reduced hypergraph and (iii) clustering refinement. The accuracy of our hypergraph clustering framework has been demonstrated by extensive experiments with comparison to other hypergraph clustering algorithms, and have been successfully applied to image segmentation, for which an appropriate hypergraph-based model have been designed. The low running times displayed by our algorithm also demonstrates that the latter, unlike the standard spectral clustering approach, can handle datasets of considerable size.     

核空间中智模糊聚类及图像分割应用

目的 为了更有效地提高中智模糊C-均值聚类对非凸不规则数据的聚类性能和噪声污染图像的分割效果,提出了核空间中智模糊均值聚类算法。方法 引入核函数概念。利用满足Mercer条件的非线性问题,用非线性变换把低维空间线性不可分的输入模式空间映射到一个先行可分的高维特征空间进行中智模糊聚类分割。结果 通过对大量图像添加不同的加性和乘性噪声进行分割测试获得的核空间中智模糊聚类算法提高了现有算法的对含噪声聚类的鲁棒性和分类性能。峰值信噪比至少提高0.8 dB。结论 本文算法具有显著的分割效果和良好的鲁棒性,并适应于医学,遥感图像处理需要。     

Improved artificial bee colony algorithm and its application in image threshold segmentation

Multimedia Tools and Applications - Image segmentation is a key problem in the field of computer vision, especially in these fields, such as image processing, analysis and understanding. The key of...     

Graphical Gaussian shape models and their application to image segmentation

This paper presents a novel approach to shape modeling and a model-based image segmentation procedure tailor-made for the proposed shape model. A common way to represent shape is based on so-called key points and leads to shape variables, which are invariant with respect to similarity transformations. We propose a graphical shape model, which relies on a certain conditional independence structure among the shape variables. Most often, it is sufficient to use a sparse underlying graph reflecting both nearby and long-distance key point interactions. Graphical shape models allow for specific shape modeling, since, e.g., for the subclass of decomposable graphical Gaussian models both model selection procedures and explicit parameter estimates are available. A further prerequisite to a successful application of graphical shape models in image analysis is provided by the "toolbox" of Markov chain Monte Carlo methods offering highly flexible and effective methods for the exploration of a specified distribution. For Bayesian image segmentation based on a graphical Gaussian shape model, we suggest applying a hybrid approach composed of the well-known Gibbs sampler and the more recent slice sampler. Shape modeling as well as image analysis are demonstrated for the segmentation of vertebrae from two-dimensional slices of computer tomography images.     

Variation-based approach to image segmentation Variation-based approach to image segmentation

A new approach to image segmentation is presented using a variation framework. Regarding the edge points as interpolating points and minimizing an energy functional to interpolate a smooth threshold surface it carries out the image segmentation. In order to preserve the edge information of the original image in the threshold surface, without unduly sharping the edge of the image, a non-convex energy functional is adopted. A relaxation algorithm with the property of global convergence, for solving the optimization problem, is proposed by introducing a binary energy. As a result the non-convex optimization problem is transformed into a series of convex optimization problems, and the problem of slow convergence or nonconvergence is solved. The presented method is also tested experimentally. Finally the method of determining the parameters in optimizing is also explored.     

Dynamic clustering using particle swarm optimization with application in image segmentation

A new dynamic clustering approach (DCPSO), based on particle swarm optimization, is proposed. This approach is applied to image segmentation. The proposed approach automatically determines the “optimum” number of clusters and simultaneously clusters the data set with minimal user interference. The algorithm starts by partitioning the data set into a relatively large number of clusters to reduce the effects of initial conditions. Using binary particle swarm optimization the “best” number of clusters is selected. The centers of the chosen clusters is then refined via the K-means clustering algorithm. The proposed approach was applied on both synthetic and natural images. The experiments conducted show that the proposed approach generally found the “optimum” number of clusters on the tested images. A genetic algorithm and random search version of dynamic clustering is presented and compared to the particle swarm version.     

图像分割技术研究与应用

图像分割是指将一副图像分解为若干互不交叠的有意义且具有相同属性的区域。图像分割是数字图像处理中的一项关键技术,其分割的准确性直接影响后续任务的有效性,因此具有十分重要的意义。现有的分割算法在不同程度上取得了一定的成功,但是图像分割的很多问题还远远没有解决,该方面的研究仍然面临很多挑战。文章分析了现有图像分割的各种算法的特点以及存在的问题,对基于图像分割的经典算法进行改进,实现了一种新的分割方法,并将其应用到机器视觉的相关产品当中,取得了良好的效果。     

Genetic algorithm application in image segmentation

In consideration of living organisms’ ability to endure for years, and their ability to adapt to surrounding environment, the mechanism of evolution is the inspiration for creating a new genetic algorithm. The goal of this paper is to examine possibilities of genetic algorithm application for segmentation of digital image data, implementation of this algorithm, and to create tools for its testing. The next goal is to examine possible choices of algorithm’s parameters, and to compare quality of the results with other segmentation methods within various image data.     

Directional EMD and its application to texture segmentation

Image processing has been a subject with systematic theory and extensive applica-tions including video processing, medical image processing, remote sensing image processing and the techniques attracting attention recently such as biometrics and visual surveillance, etc. Since multi-scale is one of the main features of natural images, there have been a series of methods for representing the quality of images such as multi-scale technique based on diffusion equation[1], that based on morphologica…