1,172 research outputs found
Fast Robust PCA on Graphs
Mining useful clusters from high dimensional data has received significant
attention of the computer vision and pattern recognition community in the
recent years. Linear and non-linear dimensionality reduction has played an
important role to overcome the curse of dimensionality. However, often such
methods are accompanied with three different problems: high computational
complexity (usually associated with the nuclear norm minimization),
non-convexity (for matrix factorization methods) and susceptibility to gross
corruptions in the data. In this paper we propose a principal component
analysis (PCA) based solution that overcomes these three issues and
approximates a low-rank recovery method for high dimensional datasets. We
target the low-rank recovery by enforcing two types of graph smoothness
assumptions, one on the data samples and the other on the features by designing
a convex optimization problem. The resulting algorithm is fast, efficient and
scalable for huge datasets with O(nlog(n)) computational complexity in the
number of data samples. It is also robust to gross corruptions in the dataset
as well as to the model parameters. Clustering experiments on 7 benchmark
datasets with different types of corruptions and background separation
experiments on 3 video datasets show that our proposed model outperforms 10
state-of-the-art dimensionality reduction models. Our theoretical analysis
proves that the proposed model is able to recover approximate low-rank
representations with a bounded error for clusterable data
Robust Manifold Nonnegative Tucker Factorization for Tensor Data Representation
Nonnegative Tucker Factorization (NTF) minimizes the euclidean distance or
Kullback-Leibler divergence between the original data and its low-rank
approximation which often suffers from grossly corruptions or outliers and the
neglect of manifold structures of data. In particular, NTF suffers from
rotational ambiguity, whose solutions with and without rotation transformations
are equally in the sense of yielding the maximum likelihood. In this paper, we
propose three Robust Manifold NTF algorithms to handle outliers by
incorporating structural knowledge about the outliers. They first applies a
half-quadratic optimization algorithm to transform the problem into a general
weighted NTF where the weights are influenced by the outliers. Then, we
introduce the correntropy induced metric, Huber function and Cauchy function
for weights respectively, to handle the outliers. Finally, we introduce a
manifold regularization to overcome the rotational ambiguity of NTF. We have
compared the proposed method with a number of representative references
covering major branches of NTF on a variety of real-world image databases.
Experimental results illustrate the effectiveness of the proposed method under
two evaluation metrics (accuracy and nmi)
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