6,607 research outputs found
A unified framework for subspace based face recognition.
Wang Xiaogang.Thesis (M.Phil.)--Chinese University of Hong Kong, 2003.Includes bibliographical references (leaves 88-91).Abstracts in English and Chinese.Abstract --- p.iAcknowledgments --- p.vTable of Contents --- p.viList of Figures --- p.viiiList of Tables --- p.xChapter Chapter 1 --- Introduction --- p.1Chapter 1.1 --- Face recognition --- p.1Chapter 1.2 --- Subspace based face recognition technique --- p.2Chapter 1.3 --- Unified framework for subspace based face recognition --- p.4Chapter 1.4 --- Discriminant analysis in dual intrapersonal subspaces --- p.5Chapter 1.5 --- Face sketch recognition and hallucination --- p.6Chapter 1.6 --- Organization of this thesis --- p.7Chapter Chapter 2 --- Review of Subspace Methods --- p.8Chapter 2.1 --- PCA --- p.8Chapter 2.2 --- LDA --- p.9Chapter 2.3 --- Bayesian algorithm --- p.12Chapter Chapter 3 --- A Unified Framework --- p.14Chapter 3.1 --- PCA eigenspace --- p.16Chapter 3.2 --- Intrapersonal and extrapersonal subspaces --- p.17Chapter 3.3 --- LDA subspace --- p.18Chapter 3.4 --- Comparison of the three subspaces --- p.19Chapter 3.5 --- L-ary versus binary classification --- p.22Chapter 3.6 --- Unified subspace analysis --- p.23Chapter 3.7 --- Discussion --- p.26Chapter Chapter 4 --- Experiments on Unified Subspace Analysis --- p.28Chapter 4.1 --- Experiments on FERET database --- p.28Chapter 4.1.1 --- PCA Experiment --- p.28Chapter 4.1.2 --- Bayesian experiment --- p.29Chapter 4.1.3 --- Bayesian analysis in reduced PCA subspace --- p.30Chapter 4.1.4 --- Extract discriminant features from intrapersonal subspace --- p.33Chapter 4.1.5 --- Subspace analysis using different training sets --- p.34Chapter 4.2 --- Experiments on the AR face database --- p.36Chapter 4.2.1 --- "Experiments on PCA, LDA and Bayes" --- p.37Chapter 4.2.2 --- Evaluate the Bayesian algorithm for different transformation --- p.38Chapter Chapter 5 --- Discriminant Analysis in Dual Subspaces --- p.41Chapter 5.1 --- Review of LDA in the null space of and direct LDA --- p.42Chapter 5.1.1 --- LDA in the null space of --- p.42Chapter 5.1.2 --- Direct LDA --- p.43Chapter 5.1.3 --- Discussion --- p.44Chapter 5.2 --- Discriminant analysis in dual intrapersonal subspaces --- p.45Chapter 5.3 --- Experiment --- p.50Chapter 5.3.1 --- Experiment on FERET face database --- p.50Chapter 5.3.2 --- Experiment on the XM2VTS database --- p.53Chapter Chapter 6 --- Eigentransformation: Subspace Transform --- p.54Chapter 6.1 --- Face sketch recognition --- p.54Chapter 6.1.1 --- Eigentransformation --- p.56Chapter 6.1.2 --- Sketch synthesis --- p.59Chapter 6.1.3 --- Face sketch recognition --- p.61Chapter 6.1.4 --- Experiment --- p.63Chapter 6.2 --- Face hallucination --- p.69Chapter 6.2.1 --- Multiresolution analysis --- p.71Chapter 6.2.2 --- Eigentransformation for hallucination --- p.72Chapter 6.2.3 --- Discussion --- p.75Chapter 6.2.4 --- Experiment --- p.77Chapter 6.3 --- Discussion --- p.83Chapter Chapter 7 --- Conclusion --- p.85Publication List of This Thesis --- p.87Bibliography --- p.8
Manifold Elastic Net: A Unified Framework for Sparse Dimension Reduction
It is difficult to find the optimal sparse solution of a manifold learning
based dimensionality reduction algorithm. The lasso or the elastic net
penalized manifold learning based dimensionality reduction is not directly a
lasso penalized least square problem and thus the least angle regression (LARS)
(Efron et al. \cite{LARS}), one of the most popular algorithms in sparse
learning, cannot be applied. Therefore, most current approaches take indirect
ways or have strict settings, which can be inconvenient for applications. In
this paper, we proposed the manifold elastic net or MEN for short. MEN
incorporates the merits of both the manifold learning based dimensionality
reduction and the sparse learning based dimensionality reduction. By using a
series of equivalent transformations, we show MEN is equivalent to the lasso
penalized least square problem and thus LARS is adopted to obtain the optimal
sparse solution of MEN. In particular, MEN has the following advantages for
subsequent classification: 1) the local geometry of samples is well preserved
for low dimensional data representation, 2) both the margin maximization and
the classification error minimization are considered for sparse projection
calculation, 3) the projection matrix of MEN improves the parsimony in
computation, 4) the elastic net penalty reduces the over-fitting problem, and
5) the projection matrix of MEN can be interpreted psychologically and
physiologically. Experimental evidence on face recognition over various popular
datasets suggests that MEN is superior to top level dimensionality reduction
algorithms.Comment: 33 pages, 12 figure
Joint & Progressive Learning from High-Dimensional Data for Multi-Label Classification
Despite the fact that nonlinear subspace learning techniques (e.g. manifold
learning) have successfully applied to data representation, there is still room
for improvement in explainability (explicit mapping), generalization
(out-of-samples), and cost-effectiveness (linearization). To this end, a novel
linearized subspace learning technique is developed in a joint and progressive
way, called \textbf{j}oint and \textbf{p}rogressive \textbf{l}earning
str\textbf{a}teg\textbf{y} (J-Play), with its application to multi-label
classification. The J-Play learns high-level and semantically meaningful
feature representation from high-dimensional data by 1) jointly performing
multiple subspace learning and classification to find a latent subspace where
samples are expected to be better classified; 2) progressively learning
multi-coupled projections to linearly approach the optimal mapping bridging the
original space with the most discriminative subspace; 3) locally embedding
manifold structure in each learnable latent subspace. Extensive experiments are
performed to demonstrate the superiority and effectiveness of the proposed
method in comparison with previous state-of-the-art methods.Comment: accepted in ECCV 201
A Unified Framework for Compositional Fitting of Active Appearance Models
Active Appearance Models (AAMs) are one of the most popular and
well-established techniques for modeling deformable objects in computer vision.
In this paper, we study the problem of fitting AAMs using Compositional
Gradient Descent (CGD) algorithms. We present a unified and complete view of
these algorithms and classify them with respect to three main characteristics:
i) cost function; ii) type of composition; and iii) optimization method.
Furthermore, we extend the previous view by: a) proposing a novel Bayesian cost
function that can be interpreted as a general probabilistic formulation of the
well-known project-out loss; b) introducing two new types of composition,
asymmetric and bidirectional, that combine the gradients of both image and
appearance model to derive better conver- gent and more robust CGD algorithms;
and c) providing new valuable insights into existent CGD algorithms by
reinterpreting them as direct applications of the Schur complement and the
Wiberg method. Finally, in order to encourage open research and facilitate
future comparisons with our work, we make the implementa- tion of the
algorithms studied in this paper publicly available as part of the Menpo
Project.Comment: 39 page
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