An review on superpixels generation algorithms

Superpixel segmentation is the oversegmentation of an image into a set of homogeneous regions. Superpixel has many specific properties and has been commonly used as supporting regions for primitives to reduce computations in various computer vision tasks. One property of superpixels is compactness, which is preferred in some applications. In this paper, we give an review on image superpixel segmentation algorithms proposed in recent years. Superpixel segmentation approaches are classified based on the compactness constraint and their main idea are introduced. We also compare these algorithms in visual and evaluate them with five common measurements.     

植物根系原位CT图像分割方法的研究进展

植物根系原位CT图像的分割是植物根系三维重建和定量分析的基础.在综述了有关领域常见图像分割算法的基础上,分析了植物根系原位CT序列图像分割研究中存在的问题,提出了原位根系CT序列图像分割算法研究的新思路.指出原位根系CT序列图像分割算法的研究应针对CT序列图像的特点、结合根系空间构型的先验知识,综合利用数学形态学、模糊理论以及神经网络等理论方法,重点在提高算法的精度和鲁棒性.     

基于马尔可夫随机场的图像分割方法综述

系统地综述了基于MRF的图像分割方法。介绍了基于MRF模型的图像分割理论框架, 给出了当前MRF图像建模研究的热点问题。概括了基于MRF模型的图像分割算法, 包括图割算法、归一化割算法、置信度传播算法等, 指出了这些算法的发展方向。     

基于内容的图像分割方法综述

图像分割是指将图像分成若干具有相似性质的区域的过程,是许多图像处理任务的预处理步骤.近年来,国内外学者主要研究基于图像内容的分割算法.在广泛调研大量文献和最新成果的基础上,将图像分割算法分为基于图论的方法、基于像素聚类的方法和语义分割方法这3种类型并分别介绍.对每类方法所包含的典型算法,尤其是最近几年利用深度网络技术的语义图像分割方法的基本思想、优缺点进行分析、对比和总结.介绍了图像分割常用的基准数据集和算法评价标准,并用实验对各种图像分割算法进行对比.最后总结全文,并对未来可能的发展趋势进行了展望.     

基于对象的视频图象分割技术

随着“流媒体”技术应用的发展和 MPEG- 4基于内容的功能的提出 ,视频图象处理领域中 ,基于对象的分割技术已成为该领域的研究热点 .如今视频分割研究已由基于镜头的分割发展到了通过提取视频对象面 ,来分割出视频对象的阶段 ,但目前基于对象的分割研究仍处于起步阶段 ,技术还很不成熟 .为了推动该技术进一步发展 ,在深入分析分割问题本质的基础上 ,首先提出从分割所利用的信息角度出发来进行分割的技术 ;然后针对分割技术的发展趋势 ,深入介绍了该研究领域国内外的最新研究算法 ,并分析了各方法技术的贡献和不足 ;最后提出了一些分割技术值得进一步深入探讨的问题和研究方向     

Performance improvement of character recognition in industrial applications using prior knowledge for more reliable segmentation

In industrial applications optical character recognition with smart cameras becomes more and more popular. Since these applications mostly have challenging environments for the systems it is most important to have very reliable character segmentation and classification algorithms. The investigations of several algorithms have shown that character segmentation is one if not the main bottleneck of character recognition. Furthermore, the requirements of robust and fast algorithms related to skew angle estimation and line segmentation, as well as tilt angle estimation, and character segmentation are high. This is the reason for introducing such algorithms that are specifically adapted to industrial applications. Additionally, a method is proposed that is based on the Bayes theorem to take account of prior knowledge for line and character segmentation. The main focus of the investigations of the character recognition system is recognition performance and speed, since real-time constraints are very hard in industrial application. Both requirements are evaluated on an image series captured with a smart camera in an industrial application.     

三维网格分割中聚类分析技术综述

三维网格分割是计算机图形学的一个重要的研究方向,近年来不断涌现出各种新的分割技术.主要关注基于聚类分析的三维网格分割技术,介绍了三维网格分割的2种常见类型,并对分割技术所转化的数学问题进行阐述,总结了一系列常用的网格属性.依据算法类型将现有算法划分为5类,所基于的分割技术分别有区域生长、多源区域生长、层次聚类、迭代聚类以及谱聚类.针对不同的分割目标和所利用的网格属性,对各分类下的分割算法进行对比讨论;同时给出4种角度的评估准则,以展示不同应用场景下各类分割算法的优缺点,并指出了三维网格分割的发展趋势和应用方向.     

甲状腺、乳腺超声影像自动分析技术综述

超声诊断是甲状腺、乳腺癌首选影像学检查和术前评估方法.但良恶性结节的超声表现存在重叠,仍欠缺定量、稳定的分析手段,严重依赖操作者经验.近年基于计算机技术的医疗影像分析水平快速发展,超声影像分析取得了一系列里程碑性的突破,为医学提供有效的诊断决策支持.本文以甲状腺、乳腺两类超声影像为对象,梳理计算机视觉、图像识别技术在医学超声图像上的学术进展,以超声影像自动诊断涉及的一系列关键技术为主线,从图像预处理、病灶区定位及分割、特征提取和分类4方面对近年主流算法进行详尽的综述分析,从算法分析、数据和评估方法等方面做多维度梳理.最后讨论了具体面向这两种腺体的超声图像计算机分析存在的问题,并对此领域的研究趋势和发展方向进行展望.     

State-of-the-art and future challenges in video scene detection: a survey

In the last 15 years much effort has been made in the field of segmentation of videos into scenes. We give a comprehensive overview of the published approaches and classify them into seven groups based on three basic classes of low-level features used for the segmentation process: (1) visual-based, (2) audio-based, (3) text-based, (4) audio-visual-based, (5) visual-textual-based, (6) audio-textual-based and (7) hybrid approaches. We try to make video scene detection approaches better assessable and comparable by making a categorization of the evaluation strategies used. This includes size and type of the dataset used as well as the evaluation metrics. Furthermore, in order to let the reader make use of the survey, we list eight possible application scenarios, including an own section for interactive video scene segmentation, and identify those algorithms that can be applied to them. At the end, current challenges for scene segmentation algorithms are discussed. In the appendix the most important characteristics of the algorithms presented in this paper are summarized in table form.     

Fast Parallel Algorithms for a Broad Class of Nonlinear Variational Diffusion Approaches

Variational segmentation and nonlinear diffusion approaches have been very active research areas in the fields of image processing and computer vision during recent years. In the present paper, we review recent advances in the development of efficient numerical algorithms for these approaches. The performance of parallel implementations of these algorithms on general-purpose hardware is assessed. A mathematically clear connection between variational models and nonlinear diffusion filters is presented that allows to interpret one approach as an approximation of the other, and vice versa. Extending this continuous connection to the fully discrete setting enables us to derive many structural similarities between efficient numerical algorithms for both frameworks. These results provide a perspective for uniform implementations of nonlinear variational models and diffusion filters on parallel architectures.     

基于DenseNet-BC网络的皮肤镜下皮肤损伤分割

针对皮肤病变图像边界分割不准确的问题,提出了一种改进的稠密卷积网络(DenseNet-BC)皮肤损伤分割算法。首先,改变传统算法层与层之间的连接方式,通过密集连接使得所有层都能直接访问从原始输入信号到损失函数的梯度,让图像特征信息得到最大化的流动。其次,为降低参数数量与网络的计算量,在瓶颈层和过渡层中采用小卷积核对输入特征图的通道数进行减半操作。将DenseNet-BC算法与VGG-16、Inception-v3以及ResNet-50等算法在ISIC 2018 Task 1皮肤病变分割数据集上进行性能比较。实验结果表明,DenseNet-BC算法的病变分割准确率为0.975,Threshold Jaccard为0.835,分割准确率较其他算法提升显著,是一种有效的皮损分割算法。     

基于D-S证据理论的多发性硬化症病灶分割算法*

多发性硬化症是一种严重威胁中枢神经功能的疾病,对其病灶自动检测方法的研究正受到越来越多的关注.基于D-S证据理论和模糊C-均值(FCM)聚类算法,提出了一种融合T1和T2加权MR图像信息的多发性硬化症自动分割算法.首先运用FCM聚类算法分别分割T1和T2加权MR图像,然后利用根据D-S证据理论得到的融合两种加权图像信息...     

Watershed-based hierarchical SAR image segmentation

Watershed transformation is a powerful image segmentation tool recently developed in mathematical morphology. In order to segment images initially oversegmented by watershed transformation, two approaches are considered: one is the thresholding of the gradient image proposed by us which is capable of keeping more salient image contours; the other is the well known centroid linkage region growing algorithm which merges regions with certain statistical similarities. By choosing suitable thresholds in the two approaches, hierarchical image segmentation algorithms can be constructed. A Ratio of Averages (ROA) edge detector is proposed to replace the morphological edge detectors prior to watershed transformation when applied to Synthetic Aperture Radar (SAR) images. Applications to SAR agricultural image segmentation with these hierarchical segmentation algorithms are presented. It is demonstrated that the algorithms are efficient in the segmentation of the SARimages and appropriate for land use applications when the land cover is made up of individual plots.     

Automatic segmentation of liver & lesion detection using H-minima transform and connecting component labeling

Automatic segmentation of the liver and the Lesion detection can be a very challenging task due to its variability in size, shape, position and the presence of other organs with similar intensities. Manual segmentation and detection of a tumor is a time-consuming task and greatly depends upon the expertise and experience of the physician. We proposed a method which consists of automatic segmentation and detection of liver and lesion using CT scan modality. H-minima transform filter, Otsu global thresholds, Morphological opening by reconstruction and modified Connected Component Labeling algorithms are applied for liver segmentation. To keep the technique simple and effective, an appropriate range of threshold values are defined to detect different types of lesions. Performance of the proposed system is evaluated and compared with the state-of-the art algorithms. The results of the comparison show that the proposed approach is robust and efficient due to its simplicity. The dice coefficient score for the hepatic segmentation is 94% while sensitivity and specificity for hepatic lesion are 93% and 87% respectively.

     

基于自适应多目标进化CNN的图像分割方法

卷积神经网络已经成为强大的分割模型,但通常为手动设计,这需要大量时间并且可能导致庞大而复杂的网络.人们对自动设计能够准确分割特定领域图像的高效网络架构越来越感兴趣,然而大部分方法或者没有考虑构建更加灵活的网络架构,或者没有考虑多个目标优化模型.鉴于此,提出一种称为AdaMo-ECNAS的自适应多目标进化卷积神经架构搜索算法,用于特定领域的图像分割,在进化过程中考虑多个性能指标并通过优化模型的多目标适应特定的数据集. AdaMo-ECNAS可以构建灵活多变的预测分割模型,其网络架构和超参数通过基于多目标进化的算法找到,算法基于自适应PBI实现3个目标进化问题,即提升预测分割的F₁-score、最大限度减少计算成本以及最大限度挖掘额外训练潜能.将AdaMo-ECNAS在两个真实数据集上进行评估,结果表明所提出方法与其他先进算法相比具有较高的竞争性,甚至是超越的.     

关于图象分割性能评估的评述

概述了图象分割性能评估发的发展,总结了分割性能评估的基本理论框架：确定图象分割性能评估指标,构造评估测试图象集,评估模型与实验分析,以及分割性能评估的常用方法：统计法,基于ＡＩ的方法和混合法。对评估模型的设计作一些尝试性的探讨。     

Improving image segmentation based on patch-weighted distance and fuzzy clustering

Image segmentation is the basis of image analysis, object tracking, and other fields. However, image segmentation is still a bottleneck due to the complexity of images. In recent years, fuzzy clustering is one of the most important selections for image segmentation, which can retain information as much as possible. However, fuzzy clustering algorithms are sensitive to image artifacts. In this study, an improved image segmentation algorithm based on patch-weighted distance and fuzzy clustering is proposed, which can be divided into two steps. First, the pixel correlation between adjacent pixels is retrieved based on patch-weighted distance, and then the pixel correlation is used to replace the influence of neighboring information in fuzzy algorithms, thereby enhancing the robustness. Experiments on simulated, natural and medical images illustrate that the proposed schema outperforms other fuzzy clustering algorithms.

     

A review of atlas-based segmentation for magnetic resonance brain images

Normal and abnormal brains can be segmented by registering the target image with an atlas. Here, an atlas is defined as the combination of an intensity image (template) and its segmented image (the atlas labels). After registering the atlas template and the target image, the atlas labels are propagated to the target image. We define this process as atlas-based segmentation. In recent years, researchers have investigated registration algorithms to match atlases to query subjects and also strategies for atlas construction. In this paper we present a review of the automated approaches for atlas-based segmentation of magnetic resonance brain images. We aim to point out the strengths and weaknesses of atlas-based methods and suggest new research directions. We use two different criteria to present the methods. First, we refer to the algorithms according to their atlas-based strategy: label propagation, multi-atlas methods, and probabilistic techniques. Subsequently, we classify the methods according to their medical target: the brain and its internal structures, tissue segmentation in healthy subjects, tissue segmentation in fetus, neonates and elderly subjects, and segmentation of damaged brains. A quantitative comparison of the results reported in the literature is also presented.