用于糖尿病视网膜病变检测的深度学习模型

近年来,深度学习在计算机视觉方面取得了巨大的进步,并在利用计算机视觉完成医学影像的阅片工作方面展现出了良好的应用前景.针对糖尿病眼底病变筛查工作,通过构建两级深度卷积神经网络,完成了原始照片的特征提取、特征组合和结果分类,最终得出筛查结果.通过与医生的诊断结果进行比较,证明了模型的输出结果与医生诊断结果之间具有高度的一致性.同时,提出了利用弱监督学习进行细粒度图像分类的改进方法.最后,对未来研究的方向进行了展望.     

深度学习在航拍场景分类中的应用

最近几十年来,航拍图片和视频在城市规划、沿海地区监视、军事任务等方面都得到了广泛的运用。因而了解航拍图片中所包含的内容,研究航拍视频所拍摄的场景类型就显得异常重要。目前流行的场景分类算法大多是针对自然场景的,很少有针对高分辨率航拍场景分类的算法。针对高分辨率航拍图片的场景分类给出了一种分层式算法。该算法首先用尺度不变特征转换（scale-invariant feature transform,SIFT）算法提取鲁棒的块局部特征,然后在视觉词袋的基础上,用经局限型波兹曼模型（restricted Boltzmarm machine,RBM）初始化的深层信念网络（deep belief network,DBN）来表示低层特征与高层视频特征之间的关系;同时深层信念网络也起到了分类器的作用。实验结果表明,该算法在处理高分辨率航拍图片场景分类问题时都要略好于目前主流算法。     

改进的SSD航拍目标检测方法

近年来,无人机技术的快速发展使得无人机地面目标检测技术成为计算机视觉领域的重要研究方向,无人机在军事侦察、交通管制等场景中具有普遍的应用价值.针对无人机场景下目标分辨率低、尺度变化大、相机快速运动、目标遮挡和光照变化等问题,提出一种基于残差网络的航拍目标检测算法.在SSD（single shot multibox detector）目标检测算法的基础上,用表征能力更强的残差网络进行基准网络的替换,用残差学习降低网络训练难度,提高目标检测精度;引入跳跃连接机制降低提取特征的冗余度,解决层数增加出现的性能退化问题.同时,针对SSD目标检测算法存在的目标重复检测和小样本漏检问题,提出一种基于特征融合的航拍目标检测算法.算法引入不同分类层的特征融合机制,把网络结构中低层视觉特征与高层语义特征有机地结合在一起.实验结果表明,算法在检测准确性和实时性方面均具有较好的表现.     

基于监督非相干字典学习的极化SAR图像舰船目标检测

提出了一种结构化非相干字典学习算法 (Structured incoherent dictionary learning, SIDL),并将该方法应用于极化SAR (Polarimetric synthetic aperture radar, PoLSAR)图像舰船目标检测. 在字典学习阶段,构建了一个新的目标函数,为了降低子字典对交叉样本的稀疏表示能力, 将子字典对交叉样本的重构能量约束及子字典互相干性约束加入到字典学习目标函数中. 通过这两个约束, 降低了子字典对交叉样本的表示能力,目标和杂波的极化特征矢量在学习获得的字典下具有良好的区分特性. 该方法不依赖于目标后向散射能量,只利用学习获得的极化字典,根据测试样本在极化字典下的稀疏表示进行目标的检测. 实验采用RADARSAT-2数据进行了验证,对比实验结果表明,本文提出的方法可以更好地抑制杂波,对弱小目标实现检测,获得了更好的检测效果.     

深度学习在目标视觉检测中的应用进展与展望

目标视觉检测是计算机视觉领域的一个重要问题,在视频监控、自主驾驶、人机交互等方面具有重要的研究意义和应用价值.近年来,深度学习在图像分类研究中取得了突破性进展,也带动着目标视觉检测取得突飞猛进的发展.本文综述了深度学习在目标视觉检测中的应用进展与展望.首先对目标视觉检测的基本流程进行总结,并介绍了目标视觉检测研究常用的公共数据集;然后重点介绍了目前发展迅猛的深度学习方法在目标视觉检测中的最新应用进展;最后讨论了深度学习方法应用于目标视觉检测时存在的困难和挑战,并对今后的发展趋势进行展望.     

无人机航拍图像语义分割研究综述

随着无人机技术的快速发展,无人机在研究领域和工业应用方面受到了广泛的关注.图像和视频是无人机感知周围环境的重要途径.图像语义分割是计算机视觉领域的研究热点,在无人驾驶、智能机器人等场景中应用广泛.无人机航拍图像语义分割是在无人机航拍图像的基础上,运用语义分割技术使无人机获得场景目标智能感知能力.介绍了语义分割技术和无人...     

Incremental Learning with Respect to New Incoming Input Attributes

Neural networks are generally exposed to a dynamic environment where the training patterns or the input attributes (features) will likely be introduced into the current domain incrementally. This Letter considers the situation where a new set of input attributes must be considered and added into the existing neural network. The conventional method is to discard the existing network and redesign one from scratch. This approach wastes the old knowledge and the previous effort. In order to reduce computational time, improve generalization accuracy, and enhance intelligence of the learned models, we present ILIA algorithms (namely ILIA1, ILIA2, ILIA3, ILIA4 and ILIA5) capable of Incremental Learning in terms of Input Attributes. Using the ILIA algorithms, when new input attributes are introduced into the original problem, the existing neural network can be retained and a new sub-network is constructed and trained incrementally. The new sub-network and the old one are merged later to form a new network for the changed problem. In addition, ILIA algorithms have the ability to decide whether the new incoming input attributes are relevant to the output and consistent with the existing input attributes or not and suggest to accept or reject them. Experimental results show that the ILIA algorithms are efficient and effective both for the classification and regression problems.     

Comparison Between Deep Learning Models and Traditional Machine Learning Approaches for Facial Expression Recognition in Ageing Adults

Journal of Computer Science and Technology - Facial expression recognition is one of the most active areas of research in computer vision since one of the non-verbal communication methods by which...     

Machine Learning for the Detection of Oil Spills in Satellite Radar Images

During a project examining the use of machine learning techniques for oil spill detection, we encountered several essential questions that we believe deserve the attention of the research community. We use our particular case study to illustrate such issues as problem formulation, selection of evaluation measures, and data preparation. We relate these issues to properties of the oil spill application, such as its imbalanced class distribution, that are shown to be common to many applications. Our solutions to these issues are implemented in the Canadian Environmental Hazards Detection System (CEHDS), which is about to undergo field testing.     

Machine Learning and Software Engineering

Machine learning deals with the issue of how to build programs that improve their performance at some task through experience. Machine learning algorithms have proven to be of great practical value in a variety of application domains. They are particularly useful for (a) poorly understood problem domains where little knowledge exists for the humans to develop effective algorithms; (b) domains where there are large databases containing valuable implicit regularities to be discovered; or (c) domains where programs must adapt to changing conditions. Not surprisingly, the field of software engineering turns out to be a fertile ground where many software development and maintenance tasks could be formulated as learning problems and approached in terms of learning algorithms. This paper deals with the subject of applying machine learning in software engineering. In the paper, we first provide the characteristics and applicability of some frequently utilized machine learning algorithms. We then summarize and analyze the existing work and discuss some general issues in this niche area. Finally we offer some guidelines on applying machine learning methods to software engineering tasks and use some software development and maintenance tasks as examples to show how they can be formulated as learning problems and approached in terms of learning algorithms.     

改进的加权极速学习机

针对加权极速学习机人为固定权重可能会错失更优权重的问题,提出了改进的加权极速学习机。该方法的多数类的初始权重设为1,使用多数类与少数类样例数的比值作为少数类的初始权重,然后通过在多数类或者少数类中添加权重调节因子,从缩小和扩大两个方向去调节权重,最后通过实验结果选出最优的权重。实验分别使用原加权极速学习机、其他权重的极速学习机和新方法在改造的UCI数据集上进行比较。结果表明新方法无论是在F-mea-sure还是G-mean上都要优于其他加权极速学习机。     

全监督学习的图像语义分割方法研究进展

近年来,随着深度学习进入计算机视觉领域,各种深度学习图像语义分割方法相继出现,其中全监督学习方法的分割效果显著超过弱监督学习方法.将全监督学习的图像语义分割方法分为五类,并对各类中最具有代表性的方法进行详细分析,重点阐述各种方法核心部分的实现过程.对语义分割领域中的主流数据集进行归纳总结,介绍了性能算法指标,并在主流数...     

一种用于入侵检测的改进的动态机器学习模型

介绍并改进了一种基于动态模型的,用于入侵检测系统的机器学习算法。该算法抽取出IP分组和TCP连接的23个属性域,经过训练得到规则集。结合改进后的模型,使用该规则集对1999 DARPA入侵检测离线评估数据集进行了测试,取得了较好的结果。     

机器视觉在光纤缺陷检测中的应用

目前,光纤已广泛应用于通信领域。光纤连接器作为精密对接光纤两个端面的部件,其重要性不言而喻,传统的端面检测方法是以人工方式对光纤显微镜下的图像是否合格进行判断,不仅精度低,而且效率低下,而利用机器视觉,由计算机来检验可以很好地解决这个问题。     

基于深度学习的目标检测算法研究综述

传统的目标检测算法主要依赖于人工选取的特征来对物体进行检测。人工提取的特征对主要针对某些特定对象,比如有的特征适合做边缘检测,有的适合做纹理检测,不具有普遍性。近年来,深度学习蓬勃发展,在计算机视觉领域比如图像分类、目标检测、图像语义分割等方面取得了重大的进展。深度学习作为一种特征学习方法能够自动学习到目标的有用特征,避免了人工提取特征,同时能够保证良好的检测效果。本文首先介绍基于深度学习的目标检测算法研究进展,其次总结目标检测算法中常见的难题与解决措施,最后对目标检测算法的可能发展方向进行展望。     

基于监督式机器学习的零件几何特征智能识别

针对在采用机器视觉的无夹具定位的壳体类零件几何参数检测过程中,需要先智能识别零件几何特征以规划检测路径的问题,提出一种基于监督式机器学习的几何特征智能识别方法。利用壳体零件待识别特征的中心位置关系构成特征矩阵,利用监督式机器学习算法进行识别,提出一种基于特征唯一性的纠错方法对分类过程中产生的识别错误进行纠正。对于所涉研究实例,零件共有4个待识别孔,在5次监督式训练后智能识别准确度达100%。     

Automatic Road Extraction from Aerial Images

The paper presents a knowledge-based method for automatic road extraction from aerial photography and high-resolution remotely sensed images. The method is based on Marr's theory of vision, which consists of low-level image processing for edge detection and linking, mid-level processing for the formation of road structure, and high-level processing for the recognition of roads. It uses a combined control strategy in which hypotheses are generated in a bottom-up mode and a top-down process is applied to predict the missing road segments. To describe road structures a generalized antiparallel pair is proposed. The hypotheses of road segments are generated based on the knowledge of their geometric and radiometric properties, which are expressed as rules in Prolog. They are verified using part–whole relationships between roads in high-resolution images and roads in low-resolution images and spatial relationships between verified road segments. Some results are presented in this paper.     

深度学习的典型目标检测算法研究综述

目标检测是计算机视觉的一个重要研究方向,其目的是精确识别给定图像中特定目标物体的类别和位置.近年来,深度卷积神经网络(Deep Convolutional Neural Networks,DCNN)所具有的特征学习和迁移学习能力,在目标检测算法特征提取、图像表达、分类与识别等方面取得了显著进展.介绍了基于深度学习目标检...     

机器学习在超声图像中的应用综述

超声图像为临床疾病检测与诊断提供重要的辅助信息,机器学习在超声图像中的应用给超声图像的分析诊断带来了新变革.从超声图像的去噪、分割、检测、分类等方面介绍了超声图像的研究现状.分类综述了近年来机器学习算法在超声图像领域的研究和应用进展.指出了基于机器学习在医学影像领域开展研究所面临的困难与挑战,并对未来研究方向进行了展望...