Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Unsupervised Performance Analysis of 3D Face Alignment   We address the problem of analyzing the performance of 3D face alignment
(3DFA) algorithms. Traditionally, performance analysis relies on carefully
annotated datasets. Here, these annotations correspond to the 3D coordinates of
a set of pre-defined facial landmarks. However, this annotation process, be it
manual or automatic, is rarely error-free, which strongly biases the analysis.
In contrast, we propose a fully unsupervised methodology based on robust
statistics and a parametric confidence test. We revisit the problem of robust
estimation of the rigid transformation between two point sets and we describe
two algorithms, one based on a mixture between a Gaussian and a uniform
distribution, and another one based on the generalized Student's
t-distribution. We show that these methods are robust to up to 50% outliers,
which makes them suitable for mapping a face, from an unknown pose to a frontal
pose, in the presence of facial expressions and occlusions. Using these methods
in conjunction with large datasets of face images, we build a statistical
frontal facial model and an associated parametric confidence metric, eventually
used for performance analysis. We empirically show that the proposed pipeline
is neither method-biased nor data-biased, and that it can be used to assess
both the performance of 3DFA algorithms and the accuracy of annotations of face
datasets.

21
The categories of this paper are: adap-org
28
The categories of this paper are: alg-geom
27
The categories of this paper are: comp-gas
3
The categories of this paper are: physics
6
The categories of this paper are: astro-ph
30
The categories of this paper are: q-alg
8
The categories of this paper are: hep-ex
34
The categories of this paper are: chem-ph
20
The categories of this paper are: acc-phys
4
The categories of this paper are: cond-mat
14
The categories of this paper are: math-ph
10
The categories of this paper are: q-bio
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The categories of this paper are: solv-int
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The categories of this paper are: eess
12
The categories of this paper are: nucl-th
7
The categories of this paper are: hep-th