375 research outputs found
Unsupervised learning of generative topic saliency for person re-identification
(c) 2014. The copyright of this document resides with its authors.
It may be distributed unchanged freely in print or electronic forms.© 2014. The copyright of this document resides with its authors. Existing approaches to person re-identification (re-id) are dominated by supervised learning based methods which focus on learning optimal similarity distance metrics. However, supervised learning based models require a large number of manually labelled pairs of person images across every pair of camera views. This thus limits their ability to scale to large camera networks. To overcome this problem, this paper proposes a novel unsupervised re-id modelling approach by exploring generative probabilistic topic modelling. Given abundant unlabelled data, our topic model learns to simultaneously both (1) discover localised person foreground appearance saliency (salient image patches) that are more informative for re-id matching, and (2) remove busy background clutters surrounding a person. Extensive experiments are carried out to demonstrate that the proposed model outperforms existing unsupervised learning re-id methods with significantly simplified model complexity. In the meantime, it still retains comparable re-id accuracy when compared to the state-of-the-art supervised re-id methods but without any need for pair-wise labelled training data
A Multiple Component Matching Framework for Person Re-Identification
Person re-identification consists in recognizing an individual that has
already been observed over a network of cameras. It is a novel and challenging
research topic in computer vision, for which no reference framework exists yet.
Despite this, previous works share similar representations of human body based
on part decomposition and the implicit concept of multiple instances. Building
on these similarities, we propose a Multiple Component Matching (MCM) framework
for the person re-identification problem, which is inspired by Multiple
Component Learning, a framework recently proposed for object detection. We show
that previous techniques for person re-identification can be considered
particular implementations of our MCM framework. We then present a novel person
re-identification technique as a direct, simple implementation of our
framework, focused in particular on robustness to varying lighting conditions,
and show that it can attain state of the art performances.Comment: Accepted paper, 16th Int. Conf. on Image Analysis and Processing
(ICIAP 2011), Ravenna, Italy, 14/09/201
Person re-identification by robust canonical correlation analysis
Person re-identification is the task to match people in surveillance cameras at different time and location. Due to significant view and pose change across non-overlapping cameras, directly matching data from different views is a challenging issue to solve. In this letter, we propose a robust canonical correlation analysis (ROCCA) to match people from different views in a coherent subspace. Given a small training set as in most re-identification problems, direct application of canonical correlation analysis (CCA) may lead to poor performance due to the inaccuracy in estimating the data covariance matrices. The proposed ROCCA with shrinkage estimation and smoothing technique is simple to implement and can robustly estimate the data covariance matrices with limited training samples. Experimental results on two publicly available datasets show that the proposed ROCCA outperforms regularized CCA (RCCA), and achieves state-of-the-art matching results for person re-identification as compared to the most recent methods
A Novel Visual Word Co-occurrence Model for Person Re-identification
Person re-identification aims to maintain the identity of an individual in
diverse locations through different non-overlapping camera views. The problem
is fundamentally challenging due to appearance variations resulting from
differing poses, illumination and configurations of camera views. To deal with
these difficulties, we propose a novel visual word co-occurrence model. We
first map each pixel of an image to a visual word using a codebook, which is
learned in an unsupervised manner. The appearance transformation between camera
views is encoded by a co-occurrence matrix of visual word joint distributions
in probe and gallery images. Our appearance model naturally accounts for
spatial similarities and variations caused by pose, illumination &
configuration change across camera views. Linear SVMs are then trained as
classifiers using these co-occurrence descriptors. On the VIPeR and CUHK Campus
benchmark datasets, our method achieves 83.86% and 85.49% at rank-15 on the
Cumulative Match Characteristic (CMC) curves, and beats the state-of-the-art
results by 10.44% and 22.27%.Comment: Accepted at ECCV Workshop on Visual Surveillance and
Re-Identification, 201
Beyond Frontal Faces: Improving Person Recognition Using Multiple Cues
We explore the task of recognizing peoples' identities in photo albums in an
unconstrained setting. To facilitate this, we introduce the new People In Photo
Albums (PIPA) dataset, consisting of over 60000 instances of 2000 individuals
collected from public Flickr photo albums. With only about half of the person
images containing a frontal face, the recognition task is very challenging due
to the large variations in pose, clothing, camera viewpoint, image resolution
and illumination. We propose the Pose Invariant PErson Recognition (PIPER)
method, which accumulates the cues of poselet-level person recognizers trained
by deep convolutional networks to discount for the pose variations, combined
with a face recognizer and a global recognizer. Experiments on three different
settings confirm that in our unconstrained setup PIPER significantly improves
on the performance of DeepFace, which is one of the best face recognizers as
measured on the LFW dataset
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