Graph-based recognition of morphological features

Automatic recognition of the shapes of objects represented as solid models is very important in design optimization. Object shape also governs ease of manufacture, ease of orientability, field use and all other life-cycle applications. Characteristic attributes of an object shape such as chamfers, protrusions and depressions, play a significant role in process planning, design for manufacture, etc. These attributes are popularly known as morphological features. In this paper, the problem of identifying such morphological features is divided into two phases: the feature extraction phase and the feature classification phase. In feature extraction, the mechanical part is decomposed into its constituent features such as holes, protrusions and depressions based on the connectivity class in the edge-face graph of the part. In feature classification, on the other hand, the extracted features are identified and classified. This paper describes a feature classification scheme based on topological and geometric attributes of a morphological feature. The feature classification scheme outlined in this paper is capable of identifying new features with minimal human interface.     

Image retrieval using edge based shape similarity with multiresolution enhanced orthogonal polynomials model

Since shape is one of the important low level features of any Content Based Image Retrieval (CBIR) system, this paper proposes a new edge based shape feature representation method with multiresolution enhanced orthogonal polynomials model and morphological operations for effective image retrieval. In the proposed method, initially the orthogonal polynomials model coefficients are computed and reordered into multiresolution subband like structure. Edge image is then obtained by utilizing the two level adaptive thresholds and local maxima of the gradient in horizontal, vertical, diagonal and anti-diagonal directions. The approximate shape boundary of the image is recovered with morphological operations. Then the Pseudo Zernike moment based global shape features, which are invariant to basic geometric transformations, are extracted. The obtained features are termed as global shape feature vector and are used for retrieving similar images with Canberra distance metric. The efficiency of the proposed method is experimented on a subset of standard Corel, Yale and MPEG-7 databases and the results are compared with existing techniques.     

基于改进形态学算子的多尺度边缘检测

图像边缘检测的关键是在尽量多地检测到图像边缘的同时更有效地抑制噪声,为此提出了一种新的基于轮廓结构元素的多尺度形态学边缘检测方法。该方法重新组合了基于轮廓结构元素形态学各种运算的优点,实现了一种改进的形态学算子;在此基础上利用改进形态学算子的多尺度运算定义了一种新的边缘检测算子。与其他形态学方法相比,文中方法不仅具有更好的噪声抑制和边缘细节保护功能,而且对结构元素的形状不敏感。     

基于机器视觉的珍珠图像采集及缺陷检测

针对珍珠表面图像采集和缺陷检测中存在的特殊问题,采用穹顶形散射光源以减小珍珠的光斑效应并提高图像质量,设计了珍珠自由落体状态下准同步方式的多幅图像获取方案,提出了用基于距离变换的自适应非线性滤波器来增强缺陷区域的对比度,对增强后的图像通过区域生长提取可疑缺陷区域,在光斑及光晕的空间分布模型上利用形态学方法去除了光斑－光晕区域,最后提取出缺陷的纹理特征、几何形状等特征参数。实验表明,该方案和算法能有效地实现珍珠表面缺陷检测。     

IC真实缺陷的边界提取和缺陷尺寸与形状的表征

为了对ＩＣ制造中真实多余物缺陷进行分类与识别,ＩＣ多余物缺陷的特征提取是非常重要的一步,文中首先提出一种基于数学形态学的ＩＣ真实多余物缺陷边界的检测方法,其次对边界进行了链码描述,最后对边界所表示的多余物缺陷进行了尺寸测量与形状分析,在预处理阶段,利用彩色ＨＳＶ模型分割原ＩＣ图像,然后用图形学开运算消除背景噪音,对开后的结果图像进行形态膨胀及形态腐蚀运算,消除多余物缺陷中的小洞噪音以获得从复杂背景     

基于曲率尺度空间的人头检测方法研究

利用人头部轮廓的形状特征,提出一种基于曲率尺度空间的人头部检测算法。算法通过比较分析得出了人头部轮廓区别于其他部分轮廓的形状特征,在多曲率尺度下,计算物体轮廓曲线上每一个点的曲率,结合形状特征信息进行人头部检测。实验结果表明,算法有效解决了复杂背景下的人头检测问题,为人头部检测提供了新的途径。     

Efficient morphological shape representation by varying overlapping levels among representative disks

The morphological skeleton transform, the morphological shape decomposition, and the overlapped morphological shape decomposition are three basic morphological shape representation schemes. In this paper, we propose a new way of generalizing these basic representation algorithms to improve representational efficiency. In all three basic algorithms, a fixed overlapping policy is used to control the overlapping relationships among representative disks of different sizes. In our new algorithm, different overlapping policies are used to generate shape components that have different overlapping relationships among themselves. The overlapping policy is selected dynamically according to local shape features. Experiments show that compared to the three basic algorithms, our algorithm produces more efficient representations with lower numbers of representative points.     

基于计算机视觉的植物黑腐病病斑分析

给出一种基于图像处理和神经网络技术进行植物黑腐病病斑分析的方法,即利用图像处理技术提取病斑的几何特征和颜色特征,其中几何特征根据病斑形状提取,并基于HSV空间提取病斑颜色矩结合红绿颜色特征作为病斑的颜色特征,最后利用神经网络加以识别,从而判断病斑所处的生长周期.给出系统的总体设计和实现方案,研究结果表明,该系统获得了较为理想的检测效果.这一思路为植物病害检测和分析提供一种新的方法.     

基于内距离形状上下文的跌倒检测方法

在全球社会老龄化的大背景下,老年人的身体健康状况和晚年生活质量需要更多的关注。跌倒在老年人群中发生率高并且带来的后果比较严重。文中提出一种应用于家庭场景的基于Inner-Distance形状上下文（ Inner-Distance Shape Context,IDSC）的跌倒检测方法。该方法通过Inner-Distance形状上下文获得视频帧前景形状的描述信息,使用形状匹配方法对视频序列中人体形状变化进行量化。对形变量化信息使用动态时间规整（ Dynamic Time Warping,DTW）方法实现跌倒行为的判定。实验结果表明该方法可有效、快速地判断跌倒,提取结果具有较好的查准率和查全率。     

高分辨率遥感图像投影分析的靠岸舰船检测

目的 高分辨率遥感图像中,靠岸舰船检测有着广泛的应用前景,其主要难点在于舰船与港口陆地在空间上紧邻,在颜色和纹理特征上相似,舰船与港口陆地难以分割。针对这种情况,利用港口岸线平直的几何特点和靠岸舰船多为舷靠的停泊特点,提出一种基于投影分析的靠岸舰船检测方法。方法 首先,对原始图像进行预处理,利用K-means聚类算法与区域生长算法相结合的方式得到海陆分割图像,利用Sobel算子与Otsu分割结合的方式获取边缘图像;然后,通过改进的Hough变换提取直线特征,结合港岸几何特性定位港口岸线;再将海陆分割后的二值图像向沿岸线和垂直岸线两个方向进行投影,根据沿岸线方向投影形态确定和分离并靠舰船,根据垂直岸线方向的投影形态定位舰船目标;最后,利用舰船尺寸、长宽比、最小外接矩形占空比特征去除虚警。结果 在15个港口场景不同分辨率的遥感图像测试集上,本文方法整体检测率达到85.4%,虚警率达17.2%;限定分辨率范围在24 m的情形下,检测率提高到93.5%,虚警率降低至5.3%。结论 本文方法简单有效,无需港口先验信息,适用于多尺度和多方向的靠岸舰船目标检测任务,对不同类型舰船形态差异具有鲁棒性,且能够分离并靠舰船。     

Soft Morphological Filtering Using a Fuzzy Model and its Application to Colour Image Processing

Abstract Soft morphological filters form a class of filters with many desirable properties. They were introduced to improve the behaviour of standard morphological filters in detail preservation and noise elimination. In this paper, a framework for soft morphological colour image processing using a fuzzy model is introduced. This extends the standard colour morphological operators in the same way that soft greyscale morphology extends the standard greyscale morphology theory. The primary and secondary operations of the new soft morphological approach are defined. The proposed operators are less sensitive to image distortion and to small variations in the shape of the objects, and perform significantly better in impulse noise removal problems, compared to standard morphological operators. Experimental results of the application to real colour images demonstrate these advantageous characteristics of the new operators. Additionally, illustrative examples that exhibit the applicability of the proposed methodology to edge detection problems are also included.An erratum to this article can be found at     

基于自调节粒子群算法的盲检测

以往基于粒子群优化的盲算法能成功实现信号盲检测,但具有算法收敛速度慢、容易陷入局部最小的缺点。文中通过分析粒子群算法的机能及参数的设置,提出一种改进的基于自调节粒子群优化的盲检测算法。算法构成思想是：基于MIMO系统的盲检测系统模型将盲检测问题转化为二次优化问题,利用改进的自调节粒子群优化算法对此优化问题进行寻优。仿真表明,改进算法具有全局收敛性好、收敛速度快、误码率低的优点,能够更好地解决盲检测问题。     

改进的数学形态学图像边缘提取算法研究

研究图像边缘优化提取问题。由于图像在进行边缘提取过程中,容易受到外界信息的干扰,特别是当受到噪声等因素影响时,造成图像边缘提取困难。为此提出了一种新的采用两层数学形态学增强操作提取图像边缘的技术。首先将利用形态学对灰度图像进行增强,并以为基础利用形态学的膨胀操作单独对边缘进行增强,然后将图像切分成小块,针对不同的小块来区分边缘与非边缘;最终经过模板滤波,获得清晰的边缘结果图像。仿真结果表明,改进的算法快速有效,在提取完整的边缘的同时,能够有效的抑制噪声和背景因素对边缘的干扰,并优于其他传统边缘提取方法。     

基于时间序列数据挖掘的故障检测方法

为了有效地检测发动机试车实验中性能参数发生的异常,提出一种基于时间序列数据挖掘的发动机故障检测方法。通过基于形态特征的时间序列特征表示方法,将发动机参数时 间序列转化为符号序列,再根据符号语义对发动机参数序列实现稳态特征和过渡态特征识别。同时,根据稳态序列的数据特征,利用基于统计特征的时间序列相似性度量结合最不相似模式发现方法实现发动机的故障检测。数值实验结果表明,与传统方法相比,本文方法能够有效地对发动机性能参数进行故障检测,并且具有较强的鲁棒性。     

Touching numeral segmentation using water reservoir concept

This paper deals with a new technique for automatic segmentation of unconstrained handwritten connected numerals. To take care of variability involved in the writing style of different individuals a robust scheme is presented here. The scheme is mainly based on features obtained from a concept based on water reservoir. A reservoir is a metaphor to illustrate the region where numerals touch. Reservoir is obtained by considering accumulation of water poured from the top or from the bottom of the numerals. At first, considering reservoir location and size, touching position (top, middle or bottom) is decided. Next, analyzing the reservoir boundary, touching position and topological features of the touching pattern, the best cutting point is determined. Finally, combined with morphological structural features the cutting path for segmentation is generated. The proposed scheme is tested on French bank check data and an accuracy about 94.8% is obtained from the system.     

一种结合形状与纹理特征的植物叶片分类方法

根据植物叶片识别植物种类对于生物科学与生态科学具有重要的辅助作用。针对叶片分类,提出了一种基于形状与纹理特征的分类算法。在进行了去噪等预处理后,通过阈值分割和数学形态学方法获取叶片区域;在分割得到的二值区域图像上提取了形状特征,在灰度图像上提取了纹理特征;在所得特征的基础上,利用BP网络对叶片进行分类。在实际图片上的实验结果表明,相比于已有算法,该方法可以达到更高的正确分类率。     

基于轮廓尖锐度的图像角点检测算法

角点是图像轮廓线最重要的特征,为了准确而快速地检测角点,提出基于轮廓尖锐度的计算方法。该算法在多尺度空间中对轮廓曲线进行高斯平滑,在局部支撑区域内计算轮廓每一点的尖锐度,结合角点筛选规则确定角点。数学推导表明该算法具备合理性和可行性。实例分析表明其抗干扰性好、运算量小、定位准确。     

轮廓检测的图像检索方法

在图像检索领域中,形状特征是图像的最重要视觉特征之一,利用形状特征进行检索可提高检索的准确性,但形状边界的自动提取一直是图像处理领域多年的难题。为了提高图像精度和准确性,提出一种基于轮廓检测的图像检索方法,首先用色彩聚类的方法对图像进行预处理,对有意义的聚类区域进行边缘追踪,然后采用基于Snake轮廓检测的算法完成图像分割,提取底层形状特征并用傅立叶描述子加以描述,进行相似度匹配。引入支持向量机的相关反馈算法来提高检索精度。实验结果表明了方法的有效性。     

Algebraic and PDE Approaches for Lattice Scale-Spaces with Global Constraints

This paper begins with analyzing the theoretical connections between levelings on lattices and scale-space erosions on reference semilattices. They both represent large classes of self-dual morphological operators that exhibit both local computation and global constraints. Such operators are useful in numerous image analysis and vision tasks including edge-preserving multiscale smoothing, image simplification, feature and object detection, segmentation, shape and motion analysis. Previous definitions and constructions of levelings were either discrete or continuous using a PDE. We bridge this gap by introducing generalized levelings based on triphase operators that switch among three phases, one of which is a global constraint. The triphase operators include as special cases useful classes of semilattice erosions. Algebraically, levelings are created as limits of iterated or multiscale triphase operators. The subclass of multiscale geodesic triphase operators obeys a semigroup, which we exploit to find PDEs that can generate geodesic levelings and continuous-scale semilattice erosions. We discuss theoretical aspects of these PDEs, propose discrete algorithms for their numerical solution which converge as iterations of triphase operators, and provide insights via image experiments.