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1.
基于稀疏表示的人脸鉴别方法通过提高字典的判别力来提高识别准确率,本文针对小样本训练,提出一种新的融合字典学习方法.首先利用Fisher判别准则及LBP金字塔进行数据预处理;其次提出新的融合字典学习模型,该模型由公共字典、类别特色字典及扰动字典三部分构成,分别提取数据共性、不同类别数据的特殊性以及异常情况下的数据扰动性;最后根据融合字典模型提出一种新的分类器,并在AR、YALE、CMU-PIE、LFW人脸数据库进行实验,结果表明本文算法具有更高的识别率和有效性.  相似文献   

2.
《Pattern recognition》2014,47(2):885-898
Empirically, we find that despite the most exclusively discriminative features owned by one specific object category, the various classes of objects usually share some common patterns, which do not contribute to the discrimination of them. Concentrating on this observation and motivated by the success of dictionary learning (DL) framework, in this paper, we propose to explicitly learn a class-specific dictionary (called particularity) for each category that captures the most discriminative features of this category, and simultaneously learn a common pattern pool (called commonality), whose atoms are shared by all the categories and only contribute to representation of the data rather than discrimination. In this way, the particularity differentiates the categories while the commonality provides the essential reconstruction for the objects. Thus, we can simply adopt a reconstruction-based scheme for classification. By reviewing the existing DL-based classification methods, we can see that our approach simultaneously learns a classification-oriented dictionary and drives the sparse coefficients as discriminative as possible. In this way, the proposed method will achieve better classification performance. To evaluate our method, we extensively conduct experiments both on synthetic data and real-world benchmarks in comparison with the existing DL-based classification algorithms, and the experimental results demonstrate the effectiveness of our method.  相似文献   

3.
在字典学习算法中,使用图像的多矢量表示相比单一矢量表示,可以获得分类精度更高且更具有鲁棒性的分类模型.本文中我们采用多种矢量表示的组合以及合理的加权对数和方案,来提升字典算法的性能.通过在公共人脸数据集上进行实验,验证了我们的方法应用于字典学习具有更高的准确度和鲁棒性.充分挖掘和利用表示多样性可以获得被观察对象的各种潜在外观以及图像高分类精度.  相似文献   

4.
Face recognition has attracted extensive interests due to its wide applications. However, there are many challenges in the real world scenario. For example, relatively few samples are available for training. Face images collected from surveillance cameras may consist of complex variations (e.g. illumination, expression, occlusion and pose). To address these challenges, in this paper we propose learning class-specific and intra-class variation dictionaries separately. Specifically, we first develop a discriminative class-specific dictionary amplifying the differences between training classes. We impose a constraint on sparse coefficients, which guarantees the sparse representation coefficients having small within-class scatter and large between-class scatter. Moreover, we introduce a new intra-class variation dictionary based on the assumption that similar variations from different classes may share some common features. The intra-class variation dictionary not only captures the inner-relationship of variations, but also addresses the limitation of the manually designed dictionaries that are person-specific. Finally, we apply the combined dictionary to adaptively represent face images. Experiments conducted on the AR, CMU-PIE, FERET and Extended Yale B databases show the effectiveness of the proposed method.  相似文献   

5.
《Pattern recognition》2014,47(2):899-913
Dictionary learning is a critical issue for achieving discriminative image representation in many computer vision tasks such as object detection and image classification. In this paper, a new algorithm is developed for learning discriminative group-based dictionaries, where the inter-concept (category) visual correlations are leveraged to enhance both the reconstruction quality and the discrimination power of the group-based discriminative dictionaries. A visual concept network is first constructed for determining the groups of visually similar object classes and image concepts automatically. For each group of such visually similar object classes and image concepts, a group-based dictionary is learned for achieving discriminative image representation. A structural learning approach is developed to take advantage of our group-based discriminative dictionaries for classifier training and image classification. The effectiveness and the discrimination power of our group-based discriminative dictionaries have been evaluated on multiple popular visual benchmarks.  相似文献   

6.
The employed dictionary plays an important role in sparse representation or sparse coding based image reconstruction and classification, while learning dictionaries from the training data has led to state-of-the-art results in image classification tasks. However, many dictionary learning models exploit only the discriminative information in either the representation coefficients or the representation residual, which limits their performance. In this paper we present a novel dictionary learning method based on the Fisher discrimination criterion. A structured dictionary, whose atoms have correspondences to the subject class labels, is learned, with which not only the representation residual can be used to distinguish different classes, but also the representation coefficients have small within-class scatter and big between-class scatter. The classification scheme associated with the proposed Fisher discrimination dictionary learning (FDDL) model is consequently presented by exploiting the discriminative information in both the representation residual and the representation coefficients. The proposed FDDL model is extensively evaluated on various image datasets, and it shows superior performance to many state-of-the-art dictionary learning methods in a variety of classification tasks.  相似文献   

7.
针对人脸图片的遮挡、伪装、光照及表情变化等问题,根据Gabor特征对遮挡、伪装、光照及表情变化有着更强的鲁棒性的特点,提出了联合Gabor误差字典和低秩表示的人脸识别算法(GDLRR)。首先对训练样本和测试样本分别进行Gabor特征提取,并将这些特征组成待测试的特征字典;然后将一个单位阵进行Gabor特征提取并训练成一个更紧凑的Gabor误差字典;最后联合Gabor误差字典和训练特征字典对测试特征字典进行低秩表示后进行分类识别。各类实验表明,提出的改进算法对人脸识别的各类问题都有着更强的鲁棒性和更高的识别准确率。  相似文献   

8.
针对当前面向组织病理图像特征提取的字典学习方法中存在着学习的无病字典与有病字典相似程度高,判别性弱的问题,本文提出一种新的面向判别性特征字典学习方法(Discriminative feature-oriented dictionary learning based on Fisher criterion,FCDFDL).该方法基于Fisher准则构造目标函数的惩罚项,最小化学习字典的类内距离与最大化学习字典的类间距离,大大降低无病字典与有病字典间的相似性.同时,优化学习字典对同类样本的重构性能,并约束学习字典对非同类样本的重构性能.然后,利用本文学习的无病与有病字典对测试样本进行稀疏表示,采用重构误差向量的统计量构造分类器.最后,分别在ADL数据集与BreaKHis数据集上验证了本文方法的有效性.实验结果表明,本文学习字典的判别性更强,获得了更优的分类性能.  相似文献   

9.
针对人脸识别中由于姿态、光照及噪声等影响造成的识别率不高的问题,提出一种基于多任务联合判别稀疏表示的人脸识别方法。首先提取人脸的局部二值特征,并基于多个特征建立一个联合分类误差与表示误差的过完备字典学习目标函数。然后,使用一种多任务联合判别字典学习方法,将多任务联合判别字典与最优线性分类器参数联合学习,得到具有良好表征和鉴别能力的字典及相应的分类器,进而提高人脸识别效果。实验结果表明,所提方法相比其他稀疏人脸识别方法具有更好的识别性能。  相似文献   

10.
Sun  Yuping  Quan  Yuhui  Fu  Jia 《Neural computing & applications》2018,30(4):1265-1275

In recent years, sparse coding via dictionary learning has been widely used in many applications for exploiting sparsity patterns of data. For classification, useful sparsity patterns should have discrimination, which cannot be well achieved by standard sparse coding techniques. In this paper, we investigate structured sparse coding for obtaining discriminative class-specific group sparsity patterns in the context of classification. A structured dictionary learning approach for sparse coding is proposed by considering the \(\ell _{2,0}\) norm on each class of data. An efficient numerical algorithm with global convergence is developed for solving the related challenging \(\ell _{2,0}\) minimization problem. The learned dictionary is decomposed into class-specific dictionaries for the classification that is done according to the minimum reconstruction error among all the classes. For evaluation, the proposed method was applied to classifying both the synthetic data and real-world data. The experiments show the competitive performance of the proposed method in comparison with several existing discriminative sparse coding methods.

  相似文献   

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