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1.
针对梯度方向直方图(HOG)算法采用网格密集的大小统一的细胞单元提取行人特征,导致大量高维度的冗余特征问题,提出了低维度特征进行行人检测的算法,建立了以空间金字塔为核心的低维度特征目标模型.该模型通过角点检测算法获取目标轮廓信息,以角点为参考点取16* 16像素区域内的梯度方向直方图作为行人特征,利用空间金字塔模型对图像进行分决,按块提取维数统一的特征向量并串联起来形成最终的特征向量.实验结果表明了该方法的准确性和有效性.  相似文献   

2.
为快速定位车辆前方的行人,提出一种基于腿部感兴趣区域梯度方向直方图(HOG)特征的行人检测方法。将可能存在行人腿部的区域作为感兴趣区域,采用Sobel算子增强腿部垂直边缘特征,并提取梯度方向直方图特征,有效地降低了特征向量的维数;在检测过程中仅扫描可能存在行人腿部的图像下半部分,并在整幅图像的块内计算HOG特征,减少了复杂背景对行人检测干扰,进一步简化了检测过程;基于垂直边缘对称性特征对检测结果进行融合。实验结果表明,该算法能在保持检测率的同时提高检测速度。  相似文献   

3.
李琳  张涛 《计算机应用》2018,38(12):3367-3371
针对传统俯视行人检测方法提取的头部特征单一、检测错误率高的问题,提出了结合改进聚合通道特征(ACF)和灰度共生矩阵(GLCM)的俯视行人检测算法。首先,将提取到的HSV颜色特征、梯度幅值大小以及改进后的梯度方向直方图(HOG)特征组合成ACF描述子;然后,采用窗口法计算改进的GLCM参数描述子,提取纹理特征,串联每个窗口的特征向量得到共生矩阵特征描述子;最后,将聚合通道和共生矩阵特征分别输入Adaboost训练得到分类器,并进行检测得到最终结果。实验结果表明,所提算法能在干扰背景存在的情况下有效检测目标,提高了检测的准确率和召回率。  相似文献   

4.
当前车辆检测算法仅使用物理特征或几何特征对目标进行分类,特征维度不够丰富导致检测不够准确。基于以上问题,文中提出了一种基于雷达与视觉特征融合的车辆检测方法,同时使用了目标的物理特征与几何特征。雷达特征选用速度、加速度等物理特征,在雷达摄像头数据融合后得到雷达目标点在图像上的感兴趣区域,在感兴趣区域上提取梯度方向直方图特征。计算梯度方向直方图的统计特征作为视觉特征,包括标准差、中位数、平均值。构建输入为雷达与视觉融合特征的神经网络R-V-DenseNet,制作数据集并训练该网络。在测试集上的实验结果证明,R-V-DenseNet相比传统的HOG-SVM方法及单传感器特征检测方法准确率有所提高,检测较为准确。  相似文献   

5.
章登义  王骞  郭雷  武小平 《计算机科学》2014,41(12):255-259
针对基于梯度方向直方图(Histogram of Oriented Gradient,HOG)特征和局部二值模式(Local Binary Patterns,LBP)特征的行人检测存在特征向量维度大、检测精度有待提高的问题,提出了一种分块特征收缩的行人检测方法。首先将样本图像划分成多个大小相同的重叠分块;然后提取各分块的HOG和LBP特征,并将两种特征融合作为分块的特征,通过该特征来训练分块分类器,根据分块分类器的行人检测精度对分块进行排序,选取检测精度较高的分块进行特征收缩;最后将特征收缩后的分块特征向量连接在一起作为最终用于行人检测的特征。在INRIA公共测试集合上的实验结果表明,该方法在降低了特征向量维度的同时提高了行人检测精度。  相似文献   

6.
马强  王文伟 《计算机应用》2015,35(11):3293-3296
针对基于纹理信息的行人特征提取算法中存在特征信息冗余度大,无法刻画人眼视觉敏感性的不足,提出一种融合人类视觉感知特性的基于显著性局部二值模式(SF-LBP)的行人纹理特征提取算法.该算法首先采用显著性计算方法提取感兴趣区域得到各部分的显著性因子;然后将显著性因子权值与行人纹理特征根据核函数相融合,生成基于SF-LBP算子的特征向量;接着统计不同区域的特征向量,形成特征直方图;最后结合自适应AdaBoost分类器构建实验平台进行实验.INRIA数据集中的实验结果显示,SF-LBP特征在检测准确率上比梯度直方图(HOG)特征、Haar特征高出2%~3%,达到97%,召回率达到90%,提高了2%左右,表明SF-LBP算子能够准确描述行人的纹理特征,提高行人检测系统的准确率.  相似文献   

7.
行人再识别过程中,由于姿势和光照等因素的变化使不同相机中所得行人的外形具有明显变化,较难提取不变性特征,导致识别率偏低.鉴于此种情况,文中提出基于融合特征的行人再识别方法,提取的特征包括HSV颜色特征、颜色直方图特征及梯度方向直方图特征,行人再识别过程分为训练阶段和识别阶段.在训练阶段,首先对训练图像集中每幅图像进行特征提取,然后利用典型相关分析获得2部相机拍摄同一行人的图像特征之间的相关性,生成相关性矩阵.在识别阶段,首先对参考图像集和测试图像集中每幅图像进行特征提取,然后将各自特征向量利用相关性矩阵进行变换,最后进行相似度度量,得到识别结果.在3个图像库上的实验表明,文中方法可以提高行人再识别的识别率.  相似文献   

8.
在物联网智能交通的车辆检测中,实时性极其重要。针对梯度方向直方图特征中特征矢量维数较多、计算量大的问题,分别对车辆梯度分布特点及支持向量机分类耗时与特征向量维数的关系进行分析,提出一种结合局部梯度矢量均值、散布矩阵特征和支持向量机进行车辆检测与提取的方法。首先,将样本图像均匀地分为若干小块;然后,分别计算块内的梯度矢量均值和散布矩阵作为样本的特征向量;最后,利用支持向量机进行分类训练与识别,其中又通过变步长法进一步减少计算量。实验结果表明,该方法的检测效果与基于梯度方向直方图特征的方法相当,但平均识别时间减少为51%。  相似文献   

9.
基于改进的WLD特征的人脸识别   总被引:1,自引:0,他引:1  
对WLD特征进行改进。改进的特征提取方法为:首先将原始人脸图像划分为若干个子块,然后提取每块图像的WLD直方图统计特征,其中的梯度方向是用Prewitt算子计算的,最后将所有分块的WLD直方图序列连接起来构成特征向量。为了验证改进特征的性能,用支持向量机进行人脸识别,人脸图像取自ORL和YALE人脸数据库。实验结果表明,采用改进后的特征可以显著提高人脸识别率。  相似文献   

10.
针对基于梯度方向直方图的行人检测尚存在实时性不足的问题,提出了一种多检测器融合的行人检测方法。利用Haar型特征的Adaboost进行头部粗检,由于图像行人姿态或尺度的原因会导致这一过程出现漏检;采用Canny算子获取图像轮廓,并根据颜色信息获取图像轮廓,通过椭圆拟合提取图像中可能检测区域;根据前面粗检的结果,对候选区域合适变换尺度,提取PHOG特征,并采用线性SVM对其进行判决。在INRIA样本库上的测试结果表明该方法是有效可行的。  相似文献   

11.
Abstract This paper describes an approach to the design of interactive multimedia materials being developed in a European Community project. The developmental process is seen as a dialogue between technologists and teachers. This dialogue is often problematic because of the differences in training, experience and culture between them. Conditions needed for fruitful dialogue are described and the generic model for learning design used in the project is explained.  相似文献   

12.
European Community policy and the market   总被引:1,自引:0,他引:1  
Abstract This paper starts with some reflections on the policy considerations and priorities which are shaping European Commission (EC) research programmes. Then it attempts to position the current projects which seek to capitalise on information and communications technologies for learning in relation to these priorities and the apparent realities of the marketplace. It concludes that while there are grounds to be optimistic about the contribution EC programmes can make to the efficiency and standard of education and training, they are still too technology driven.  相似文献   

13.
融合集成方法已经广泛应用在模式识别领域,然而一些基分类器实时性能稳定性较差,导致多分类器融合性能差,针对上述问题本文提出了一种新的基于多分类器的子融合集成分类器系统。该方法考虑在度量层融合层次之上通过对各类基多分类器进行动态选择,票数最多的类别作为融合系统中对特征向量识别的类别,构成一种新的自适应子融合集成分类器方法。实验表明,该方法比传统的分类器以及分类融合方法识别准确率明显更高,具有更好的鲁棒性。  相似文献   

14.
Development of software intensive systems (systems) in practice involves a series of self-contained phases for the lifecycle of a system. Semantic and temporal gaps, which occur among phases and among developer disciplines within and across phases, hinder the ongoing development of a system because of the interdependencies among phases and among disciplines. Such gaps are magnified among systems that are developed at different times by different development teams, which may limit reuse of artifacts of systems development and interoperability among the systems. This article discusses such gaps and a systems development process for avoiding them.  相似文献   

15.
This paper presents control charts models and the necessary simulation software for the location of economic values of the control parameters. The simulation program is written in FORTRAN, requires only 10K of main storage, and can run on most mini and micro computers. Two models are presented - one describes the process when it is operating at full capacity and the other when the process is operating under capacity. The models allow the product quality to deteriorate to a further level before an existing out-of-control state is detected, and they can also be used in situations where no prior knowledge exists of the out-of-control causes and the resulting proportion defectives.  相似文献   

16.
Going through a few examples of robot artists who are recognized worldwide, we try to analyze the deepest meaning of what is called “robot art” and the related art field definition. We also try to highlight its well-marked borders, such as kinetic sculptures, kinetic art, cyber art, and cyberpunk. A brief excursion into the importance of the context, the message, and its semiotics is also provided, case by case, together with a few hints on the history of this discipline in the light of an artistic perspective. Therefore, the aim of this article is to try to summarize the main characteristics that might classify robot art as a unique and innovative discipline, and to track down some of the principles by which a robotic artifact can or cannot be considered an art piece in terms of social, cultural, and strictly artistic interest. This work was presented in part at the 13th International Symposium on Artificial Life and Robotics, Oita, Japan, January 31–February 2, 2008  相似文献   

17.
Although there are many arguments that logic is an appropriate tool for artificial intelligence, there has been a perceived problem with the monotonicity of classical logic. This paper elaborates on the idea that reasoning should be viewed as theory formation where logic tells us the consequences of our assumptions. The two activities of predicting what is expected to be true and explaining observations are considered in a simple theory formation framework. Properties of each activity are discussed, along with a number of proposals as to what should be predicted or accepted as reasonable explanations. An architecture is proposed to combine explanation and prediction into one coherent framework. Algorithms used to implement the system as well as examples from a running implementation are given.  相似文献   

18.
This paper provides the author's personal views and perspectives on software process improvement. Starting with his first work on technology assessment in IBM over 20 years ago, Watts Humphrey describes the process improvement work he has been directly involved in. This includes the development of the early process assessment methods, the original design of the CMM, and the introduction of the Personal Software Process (PSP)SM and Team Software Process (TSP){SM}. In addition to describing the original motivation for this work, the author also reviews many of the problems he and his associates encountered and why they solved them the way they did. He also comments on the outstanding issues and likely directions for future work. Finally, this work has built on the experiences and contributions of many people. Mr. Humphrey only describes work that he was personally involved in and he names many of the key contributors. However, so many people have been involved in this work that a full list of the important participants would be impractical.  相似文献   

19.
基于复小波噪声方差显著修正的SAR图像去噪   总被引:4,自引:1,他引:3  
提出了一种基于复小波域统计建模与噪声方差估计显著性修正相结合的合成孔径雷达(Synthetic Aperture Radar,SAR)图像斑点噪声滤波方法。该方法首先通过对数变换将乘性噪声模型转化为加性噪声模型,然后对变换后的图像进行双树复小波变换(Dualtree Complex Wavelet Transform,DCWT),并对复数小波系数的统计分布进行建模。在此先验分布的基础上,通过运用贝叶斯估计方法从含噪系数中恢复原始系数,达到滤除噪声的目的。实验结果表明该方法在去除噪声的同时保留了图像的细节信息,取得了很好的降噪效果。  相似文献   

20.
Abstract  This paper considers some results of a study designed to investigate the kinds of mathematical activity undertaken by children (aged between 8 and 11) as they learned to program in LOGO. A model of learning modes is proposed, which attempts to describe the ways in which children used and acquired understanding of the programming/mathematical concepts involved. The remainder of the paper is concerned with discussing the validity and limitations of the model, and its implications for further research and curriculum development.  相似文献   

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