Face recognition based on symmetrical linear discriminate analysis

Linear Discriminant Analysis (LDA) has been one of the popular subspace methods for face recognition. But this method suffers from the small sample size (SSS) problem, also known as 'curse of dimensionality'. Various techniques have been proposed in literature to overcome this limitation. But it is still unclear which method provides the best solution to SSS problem. In this paper, we have investigated the performance of some popular subspace methods such as principal component analysis (PCA), PCA + LDA, LDA via QR decomposition, Null-space LDA, Exponential Discriminant Analysis (EDA), PCA+EDA etc. Extensive experiments have been performed on five publically available face datasets viz. AR, CMU-PIE, PIX, Yale and YaleB. The performance is measured in terms of average classification accuracy. Experimental results show that the performance increases with the increase in the number of images per person in training set irrespective of the datasets. There is no clear winner among the subspace methods under investigation. But, the performance of PCA+LDA and PCA+EDA is consistent in tackling SSS problem irrespective of the dataset and can also handle the illumination variation in face recognition.

A new image feature extraction method for face recognition called Tri-direction 2D-Fisher Discriminant Analysis (T2D-FDA) is proposed to deal with the Small Sample Size (SSS) problem in conventional 1D-Fisher Discriminant Analysis (1D-FDA). Moreover, the essence of T2D-FDA is investigated, and the equivalence of the left-multiplying 2D-FDA of the original image matrices and the left-multiplying D2D-FDA of diagonal image matrices is verified if each column is viewed as a computational unit. Different from the 1D-LDA based approaches, the T2D-FDA is based on 2D image matrices rather than column vectors, so the image matrix does not need to be transformed into a long vector before feature extraction. The advantage arising in this way is that the SSS problem does not exist anymore because within-class scatter matrices constructed is full-rank in T2D-FDA. The proposed method is applied to face recognition where only few training images exist for each subject. Experiment results show T2D-FDA outperforms the current linear subspace methods in SSS problem on four public databases: ORL, Yale, AR and FERET face databases.

Complexity-reduced implementations of complete and null-space-based linear discriminant analysis

Click here for manuscript sample templateThe tongue-machine interface (TMI) between the paralyzed person and computer makes possible to manage assistive technologies. Severely disabled individuals caused by traumatic brain and spinal cord injuries need continuous help to carry out everyday routines. The cranial nerve is arisen directly from the brain to connect the tongue that is one of the last affected organs in neuromuscular disorders. Besides, the tongue has highly capable of mobility located in the oral cavity which also provides cosmetic advantages. These crucial skills make the tongue to be an odd organ employed in the human-machine interfaces. In this study, it was aimed to investigate 1-D extraction and develop a novel tongue-machine interface using the glossokinetic potential responses (GKPs). This rare used bio-signs are occurred by contacting the buccal walls with the tip of the tongue in the oral cavity. Our study, named as GKP-based TMI measuring the glossokinetic potential responses over the scalp may serve paralyzed persons an unobtrusive, natural and reliable communication channel. In this work, 8 males and 2 females, aged between 22-34 naive healthy subjects have participated. Linear discriminant analysis and support vector machine were implemented with mean-absolute value and power spectral density feature extraction process. Moreover independent component analysis (ICA) and principal component analysis (PCA) were used to evaluate the reduced dimension of the data set for GKPs in machine learning algorithms. And the highest result was obtained as 97.03%.

Linear Discriminant Analysis (LDA) is a popular statistical method for both feature extraction and dimensionality reduction in face recognition. The major drawback of LDA is the so-called small sample size (3S) problem. This problem always occurs when the total number of training samples is smaller than the dimension of feature space. Under this situation, the within-class scatter matrix Sw becomes singular and LDA approach cannot be implemented directly. To overcome the 3S problem, this paper proposes a novel wavelet-face based subspace LDA algorithm. Wavelet-face feature extraction and dimensionality reduction are based on two-level D4-filter wavelet transform and discarding the null space of total class scatter matrix St. It is shown that our obtained projection matrix satisfies the uncorrelated constraint conditions. Hence in the sense of statistical uncorrelation, this projection matrix is optimal. The proposed method for face recognition has been evaluated with two public available databases, namely ORL and FERET databases. Comparing with existing LDA-based methods to solve the 3S problem, our method gives the best performance.

iLDA: A new dimensional reduction method for non-Gaussian and small sample size datasets

Classical Linear Discriminant Analysis (LDA) is usually suffers from the small sample size (SSS) problem when dealing with the high dimensional face data. Many methods have been proposed for solving this problem such as Fisherface and Null Space LDA (N-LDA), but these methods are overfitted to the training set and inevitably lose some useful discriminative information in many cases. To effectively utilize nearly all useful discriminative information, a not completely random sampling framework for the integration of multiple features is developed. However, this method has the following main disadvantage: By directly employing feature extraction, the newly constructed variables may contain lots of information originated from those redundant features in the original space. So, in this paper, we introduce a new random sampling LDA by incorporating feature selection for face recognition, that is, some redundant features are removed using the given feature selection methods at first, and then PCA is employed, finally we use random sampling to generate multiple feature subsets. Along this, corresponding weak LDA classifiers are naturally generated and an integrated classifier is developed using a fusion rule. Experiments on 4 face datasets (AR, ORL, Yale, YaleB) show the effectiveness of our algorithm.

We have investigated the illumination variation in the images taken under a wide variety of lighting conditions in independent component analysis (ICA) and principal component analysis (PCA) subspaces. In ICA subspace, an independent component (IC) is proved to be the composite factor of illumination variation. In PCA subspace, almost all the principal components (PC?s) are proved to contain illumination variation, and a 15-D and 50-D in PCA subspace have more than 5% and 2% related deviation of illumination variation in images, respectively.

In this paper, we propose a method by engaging the One Class Support Vector Machine (OC-SVM) in the identification of Diffractive Optically Variable Images (DOVIs). OC-SVM, as a special SVM, can solve the problems of high-dimensional data sets and small sample size (SSS) with positive and negative unbalance training data. Image feature matrix is built by extracting image features from texture aspects. OC-SVM can be trained with the high-dimensional matrix directly, and does not have to reduce the dimensionality of feature matrix as the usual methods. The experiment results show the effectiveness of the proposed approach against Linear Discriminant Analysis. Considering time cost and correct classification rate, OC-SVM is suitable for the identification of DOVIs.

We made two contributions in this paper. First, a new method called two-dimensional fisher discriminant analysis (2D-FDA) is proposed to deal with the small sample size (SSS) problem in LDA based face recognition. Second, appearance and depth information are combined to improve face recognition rate. Different from the conventional 1D-FDA (PCA plus LDA) approaches, 2D-FDA is based on 2D image matrices rather than column vectors so the image matrix does not need to be transformed into a long vector before feature extraction. The advantage arising in this way is that the SSS problem does not exist any more because the between-class and within-class scatter matrices constructed in 2D-FDA are both of full-rank. 2D FDA and 1D FDA (PCA plus LDA) are evaluated respectively with a problem that combines appearance and depth information for face recognition. We investigate the complete range of linear combinations to reveal the interplay between these two paradigms. The recognition rate by the combination is better than either appearance alone or depth alone. It is verified that 2D-FDA outperforms 1D FDA

Reliable management of modern cloud computing infrastructures is unrealizable without monitoring and analysis of a huge number of system indicators (metrics) as time series data stored in big databases. Efficient storage and processing of collected historical data from all objects of those infrastructures are technology challenges for this Big Data application. We propose a data compression framework for databases of time series that applies correlation content of the data set. Specifically, the fundamental statistical concepts of independent component analysis (ICA) and principal component analysis (PCA) are employed to demonstrate the viability of the approach. We experimentally show significant compression rates for real data sets from IT systems.

Exploring sex classification from earprints - A comparison of supervised machine learning algorithms and conventional linear discriminant analysis.

This is the author’s version of a work that was submitted/accepted for pub-lication in the following source:

Statistical analysis of wind-induced pressure fields and PIV measurements on two buildings

Linear discriminant analysis (LDA) is a popular feature extraction technique in statistical pattern recognition. However, it often suffers from the small sample size problem when dealing with the high dimensional image data. Moreover, while LDA is guaranteed to find the best directions when each class has a Gaussian density with a common covariance matrix, it can fail if the class densities are more general. In this paper, a new feature extraction method, nonparametric maximum margin criterion (NMMC), is proposed. NMMC finds the important discriminant directions without assuming the class densities belong to any particular parametric family, and it does not depend on the nonsingularity of the within-class scatter matrix. Our experimental results on the ATT and FERET face databases demonstrate that NMMC outperforms the existing variant LDA methods and the other state-of-art face recognition approaches.