101,745 research outputs found

    Low dimensional Surface Parameterisation with application in biometrics

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    This paper describes initial results from a novel low dimensional surface parameterisation approach based on a modified iterative closest point (ICP) registration process which uses vertex based principal component analysis (PCA) to incorporate a deformable element into registration process. Using this method a 3D surface is represented by a shape space vector of much smaller dimensionality than the dimensionality of the original data space vector. The proposed method is tested on both simulated 3D faces with different facial expressions and real face data. It is shown that the proposed surface representation can be potentially used as feature space for a facial expression recognition system

    Feature Extraction Technique of PCA for Face Recognition With Accuracy Enhancement

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    Face recognition is a very complex task in the area of image processing and computer vision. This becomes important because it applies on many real life applications like Security, identification, crowd surveillance, Video surveillance etc. This paper is proposed the PCA based Face recognition. PCA is a holistic based Statistical method which is used to extract the feature from face image and to decrease the large dimensionality of the data to the smaller dimensionality of feature space, then classification is done using Euclidian distance classifier to recognize the face. The proposed method is worked on Yale Database and evaluate under varying conditions like Illumination variant for Center, Left and Right, Different Facial Expression like Happy, Sad, Normal, Wink , Surprised and Sleepy , Wearing spectacles and without it for Frontal Face View. The proposed work demonstrates the recognition rate for given Dataset

    Beyond Gauss: Image-Set Matching on the Riemannian Manifold of PDFs

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    State-of-the-art image-set matching techniques typically implicitly model each image-set with a Gaussian distribution. Here, we propose to go beyond these representations and model image-sets as probability distribution functions (PDFs) using kernel density estimators. To compare and match image-sets, we exploit Csiszar f-divergences, which bear strong connections to the geodesic distance defined on the space of PDFs, i.e., the statistical manifold. Furthermore, we introduce valid positive definite kernels on the statistical manifolds, which let us make use of more powerful classification schemes to match image-sets. Finally, we introduce a supervised dimensionality reduction technique that learns a latent space where f-divergences reflect the class labels of the data. Our experiments on diverse problems, such as video-based face recognition and dynamic texture classification, evidence the benefits of our approach over the state-of-the-art image-set matching methods

    Top-down segmentation of non-rigid visual objects using derivative-based search on sparse manifolds

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    The solution for the top-down segmentation of non rigid visual objects using machine learning techniques is generally regarded as too complex to be solved in its full generality given the large dimensionality of the search space of the explicit representation of the segmentation contour. In order to reduce this complexity, the problem is usually divided into two stages: rigid detection and non-rigid segmentation. The rationale is based on the fact that the rigid detection can be run in a lower dimensionality space (i.e., less complex and faster) than the original contour space, and its result is then used to constrain the non-rigid segmentation. In this paper, we propose the use of sparse manifolds to reduce the dimensionality of the rigid detection search space of current state-of-the-art top-down segmentation methodologies. The main goals targeted by this smaller dimensionality search space are the decrease of the search running time complexity and the reduction of the training complexity of the rigid detector. These goals are attainable given that both the search and training complexities are function of the dimensionality of the rigid search space. We test our approach in the segmentation of the left ventricle from ultrasound images and lips from frontal face images. Compared to the performance of state-of-the-art non-rigid segmentation system, our experiments show that the use of sparse manifolds for the rigid detection leads to the two goals mentioned above. © 2013 IEEE.Jacinto C. Nascimento, Gustavo Carneirohttp://www.pamitc.org/cvpr13

    Persistent homology to analyse 3D faces and assess body weight gain

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    In this paper, we analyse patterns in face shape variation due to weight gain. We propose the use of persistent homology descriptors to get geometric and topological information about the configuration of anthropometric 3D face landmarks. In this way, evaluating face changes boils down to comparing the descriptors computed on 3D face scans taken at different times. By applying dimensionality reduction techniques to the dissimilarity matrix of descriptors, we get a space in which each face is a point and face shape variations are encoded as trajectories in that space. Our results show that persistent homology is able to identify features which are well related to overweight and may help assessing individual weight trends. The research was carried out in the context of the European project SEMEOTICONS, which developed a multisensory platform which detects and monitors over time facial signs of cardio-metabolic risk

    Feature Selection for Face Detection

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    We present a new method to select features for a face detection system using Support Vector Machines (SVMs). In the first step we reduce the dimensionality of the input space by projecting the data into a subset of eigenvectors. The dimension of the subset is determined by a classification criterion based on minimizing a bound on the expected error probability of an SVM. In the second step we select features from the SVM feature space by removing those that have low contributions to the decision function of the SVM

    An Adaptive Approach for Eigenfaces - based Facial Recognition

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    The fundamental target is to show the specific faces and recognize the pictures from the substantial number of put away faces with some continuous variety with dropping down the dimensionality space. Her we focus on to diminish the space eccentrics and to got the exact feature vectors and consider all the previous approaches for the same .This paper focuses on mathematical rigor and the conventional methodology aspects over the face recognition classifier. Considering all the conventional approach for Eigen face approaches this paper presents a comparative analysis in more efficient manner. The focus is not to make a new classifier but to analyze the conventional approach with proposed method
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