4,117 research outputs found
Robust Face Recognition using Local Illumination Normalization and Discriminant Feature Point Selection
Face recognition systems must be robust to the variation of various factors
such as facial expression, illumination, head pose and aging. Especially, the
robustness against illumination variation is one of the most important problems
to be solved for the practical use of face recognition systems. Gabor wavelet
is widely used in face detection and recognition because it gives the
possibility to simulate the function of human visual system. In this paper, we
propose a method for extracting Gabor wavelet features which is stable under
the variation of local illumination and show experiment results demonstrating
its effectiveness
An Effective Unconstrained Correlation Filter and Its Kernelization for Face Recognition
In this paper, an effective unconstrained correlation filter called Uncon-
strained Optimal Origin Tradeoff Filter (UOOTF) is presented and applied to
robust face recognition. Compared with the conventional correlation filters in
Class-dependence Feature Analysis (CFA), UOOTF improves the overall performance
for unseen patterns by removing the hard constraints on the origin correlation
outputs during the filter design. To handle non-linearly separable
distributions between different classes, we further develop a non- linear
extension of UOOTF based on the kernel technique. The kernel ex- tension of
UOOTF allows for higher flexibility of the decision boundary due to a wider
range of non-linearity properties. Experimental results demon- strate the
effectiveness of the proposed unconstrained correlation filter and its
kernelization in the task of face recognition
Human Emotional Facial Expression Recognition
An automatic Facial Expression Recognition (FER) model with Adaboost face
detector, feature selection based on manifold learning and synergetic prototype
based classifier has been proposed. Improved feature selection method and
proposed classifier can achieve favorable effectiveness to performance FER in
reasonable processing time
A Face Recognition approach based on entropy estimate of the nonlinear DCT features in the Logarithm Domain together with Kernel Entropy Component Analysis
This paper exploits the feature extraction capabilities of the discrete
cosine transform (DCT) together with an illumination normalization approach in
the logarithm domain that increase its robustness to variations in facial
geometry and illumination. Secondly in the same domain the entropy measures are
applied on the DCT coefficients so that maximum entropy preserving pixels can
be extracted as the feature vector. Thus the informative features of a face can
be extracted in a low dimensional space. Finally, the kernel entropy component
analysis (KECA) with an extension of arc cosine kernels is applied on the
extracted DCT coefficients that contribute most to the entropy estimate to
obtain only those real kernel ECA eigenvectors that are associated with
eigenvalues having high positive entropy contribution. The resulting system was
successfully tested on real image sequences and is robust to significant
partial occlusion and illumination changes, validated with the experiments on
the FERET, AR, FRAV2D and ORL face databases. Experimental comparison is
demonstrated to prove the superiority of the proposed approach in respect to
recognition accuracy. Using specificity and sensitivity we find that the best
is achieved when Renyi entropy is applied on the DCT coefficients. Extensive
experimental comparison is demonstrated to prove the superiority of the
proposed approach in respect to recognition accuracy. Moreover, the proposed
approach is very simple, computationally fast and can be implemented in any
real-time face recognition system.Comment: 9 pages,Published Online August 2013 in MECS. International Journal
of Information Technology and Computer Science, 2013. arXiv admin note: text
overlap with arXiv:1112.3712 by other author
Facial expression recognition based on local region specific features and support vector machines
Facial expressions are one of the most powerful, natural and immediate means
for human being to communicate their emotions and intensions. Recognition of
facial expression has many applications including human-computer interaction,
cognitive science, human emotion analysis, personality development etc. In this
paper, we propose a new method for the recognition of facial expressions from
single image frame that uses combination of appearance and geometric features
with support vector machines classification. In general, appearance features
for the recognition of facial expressions are computed by dividing face region
into regular grid (holistic representation). But, in this paper we extracted
region specific appearance features by dividing the whole face region into
domain specific local regions. Geometric features are also extracted from
corresponding domain specific regions. In addition, important local regions are
determined by using incremental search approach which results in the reduction
of feature dimension and improvement in recognition accuracy. The results of
facial expressions recognition using features from domain specific regions are
also compared with the results obtained using holistic representation. The
performance of the proposed facial expression recognition system has been
validated on publicly available extended Cohn-Kanade (CK+) facial expression
data sets.Comment: Facial expressions, Local representation, Appearance features,
Geometric features, Support vector machine
New Fuzzy LBP Features for Face Recognition
There are many Local texture features each very in way they implement and
each of the Algorithm trying improve the performance. An attempt is made in
this paper to represent a theoretically very simple and computationally
effective approach for face recognition. In our implementation the face image
is divided into 3x3 sub-regions from which the features are extracted using the
Local Binary Pattern (LBP) over a window, fuzzy membership function and at the
central pixel. The LBP features possess the texture discriminative property and
their computational cost is very low. By utilising the information from LBP,
membership function, and central pixel, the limitations of traditional LBP is
eliminated. The bench mark database like ORL and Sheffield Databases are used
for the evaluation of proposed features with SVM classifier. For the proposed
approach K-fold and ROC curves are obtained and results are compared
A Semi-supervised Spatial Spectral Regularized Manifold Local Scaling Cut With HGF for Dimensionality Reduction of Hyperspectral Images
Hyperspectral images (HSI) contain a wealth of information over hundreds of
contiguous spectral bands, making it possible to classify materials through
subtle spectral discrepancies. However, the classification of this rich
spectral information is accompanied by the challenges like high dimensionality,
singularity, limited training samples, lack of labeled data samples,
heteroscedasticity and nonlinearity. To address these challenges, we propose a
semi-supervised graph based dimensionality reduction method named
`semi-supervised spatial spectral regularized manifold local scaling cut'
(S3RMLSC). The underlying idea of the proposed method is to exploit the limited
labeled information from both the spectral and spatial domains along with the
abundant unlabeled samples to facilitate the classification task by retaining
the original distribution of the data. In S3RMLSC, a hierarchical guided filter
(HGF) is initially used to smoothen the pixels of the HSI data to preserve the
spatial pixel consistency. This step is followed by the construction of linear
patches from the nonlinear manifold by using the maximal linear patch (MLP)
criterion. Then the inter-patch and intra-patch dissimilarity matrices are
constructed in both spectral and spatial domains by regularized manifold local
scaling cut (RMLSC) and neighboring pixel manifold local scaling cut (NPMLSC)
respectively. Finally, we obtain the projection matrix by optimizing the
updated semi-supervised spatial-spectral between-patch and total-patch
dissimilarity. The effectiveness of the proposed DR algorithm is illustrated
with publicly available real-world HSI datasets
A Survey of the Trends in Facial and Expression Recognition Databases and Methods
Automated facial identification and facial expression recognition have been
topics of active research over the past few decades. Facial and expression
recognition find applications in human-computer interfaces, subject tracking,
real-time security surveillance systems and social networking. Several holistic
and geometric methods have been developed to identify faces and expressions
using public and local facial image databases. In this work we present the
evolution in facial image data sets and the methodologies for facial
identification and recognition of expressions such as anger, sadness,
happiness, disgust, fear and surprise. We observe that most of the earlier
methods for facial and expression recognition aimed at improving the
recognition rates for facial feature-based methods using static images.
However, the recent methodologies have shifted focus towards robust
implementation of facial/expression recognition from large image databases that
vary with space (gathered from the internet) and time (video recordings). The
evolution trends in databases and methodologies for facial and expression
recognition can be useful for assessing the next-generation topics that may
have applications in security systems or personal identification systems that
involve "Quantitative face" assessments.Comment: 16 pages, 4 figures, 3 tables, International Journal of Computer
Science and Engineering Survey, October, 201
SuperPCA: A Superpixelwise PCA Approach for Unsupervised Feature Extraction of Hyperspectral Imagery
As an unsupervised dimensionality reduction method, principal component
analysis (PCA) has been widely considered as an efficient and effective
preprocessing step for hyperspectral image (HSI) processing and analysis tasks.
It takes each band as a whole and globally extracts the most representative
bands. However, different homogeneous regions correspond to different objects,
whose spectral features are diverse. It is obviously inappropriate to carry out
dimensionality reduction through a unified projection for an entire HSI. In
this paper, a simple but very effective superpixelwise PCA approach, called
SuperPCA, is proposed to learn the intrinsic low-dimensional features of HSIs.
In contrast to classical PCA models, SuperPCA has four main properties. (1)
Unlike the traditional PCA method based on a whole image, SuperPCA takes into
account the diversity in different homogeneous regions, that is, different
regions should have different projections. (2) Most of the conventional feature
extraction models cannot directly use the spatial information of HSIs, while
SuperPCA is able to incorporate the spatial context information into the
unsupervised dimensionality reduction by superpixel segmentation. (3) Since the
regions obtained by superpixel segmentation have homogeneity, SuperPCA can
extract potential low-dimensional features even under noise. (4) Although
SuperPCA is an unsupervised method, it can achieve competitive performance when
compared with supervised approaches. The resulting features are discriminative,
compact, and noise resistant, leading to improved HSI classification
performance. Experiments on three public datasets demonstrate that the SuperPCA
model significantly outperforms the conventional PCA based dimensionality
reduction baselines for HSI classification. The Matlab source code is available
at https://github.com/junjun-jiang/SuperPCAComment: 13 pages, 10 figures, Accepted by IEEE TGR
Joint Projection and Dictionary Learning using Low-rank Regularization and Graph Constraints
In this paper, we aim at learning simultaneously a discriminative dictionary
and a robust projection matrix from noisy data. The joint learning, makes the
learned projection and dictionary a better fit for each other, so a more
accurate classification can be obtained. However, current prevailing joint
dimensionality reduction and dictionary learning methods, would fail when the
training samples are noisy or heavily corrupted. To address this issue, we
propose a joint projection and dictionary learning using low-rank
regularization and graph constraints (JPDL-LR). Specifically, the
discrimination of the dictionary is achieved by imposing Fisher criterion on
the coding coefficients. In addition, our method explicitly encodes the local
structure of data by incorporating a graph regularization term, that further
improves the discriminative ability of the projection matrix. Inspired by
recent advances of low-rank representation for removing outliers and noise, we
enforce a low-rank constraint on sub-dictionaries of all classes to make them
more compact and robust to noise. Experimental results on several benchmark
datasets verify the effectiveness and robustness of our method for both
dimensionality reduction and image classification, especially when the data
contains considerable noise or variations
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