22,591 research outputs found
Context Forest for efficient object detection with large mixture models
We present Context Forest (ConF), a technique for predicting properties of
the objects in an image based on its global appearance. Compared to standard
nearest-neighbour techniques, ConF is more accurate, fast and memory efficient.
We train ConF to predict which aspects of an object class are likely to appear
in a given image (e.g. which viewpoint). This enables to speed-up
multi-component object detectors, by automatically selecting the most relevant
components to run on that image. This is particularly useful for detectors
trained from large datasets, which typically need many components to fully
absorb the data and reach their peak performance. ConF provides a speed-up of
2x for the DPM detector [1] and of 10x for the EE-SVM detector [2]. To show
ConF's generality, we also train it to predict at which locations objects are
likely to appear in an image. Incorporating this information in the detector
score improves mAP performance by about 2% by removing false positive
detections in unlikely locations
Background Subtraction in Real Applications: Challenges, Current Models and Future Directions
Computer vision applications based on videos often require the detection of
moving objects in their first step. Background subtraction is then applied in
order to separate the background and the foreground. In literature, background
subtraction is surely among the most investigated field in computer vision
providing a big amount of publications. Most of them concern the application of
mathematical and machine learning models to be more robust to the challenges
met in videos. However, the ultimate goal is that the background subtraction
methods developed in research could be employed in real applications like
traffic surveillance. But looking at the literature, we can remark that there
is often a gap between the current methods used in real applications and the
current methods in fundamental research. In addition, the videos evaluated in
large-scale datasets are not exhaustive in the way that they only covered a
part of the complete spectrum of the challenges met in real applications. In
this context, we attempt to provide the most exhaustive survey as possible on
real applications that used background subtraction in order to identify the
real challenges met in practice, the current used background models and to
provide future directions. Thus, challenges are investigated in terms of
camera, foreground objects and environments. In addition, we identify the
background models that are effectively used in these applications in order to
find potential usable recent background models in terms of robustness, time and
memory requirements.Comment: Submitted to Computer Science Revie
Beyond Pixels: A Comprehensive Survey from Bottom-up to Semantic Image Segmentation and Cosegmentation
Image segmentation refers to the process to divide an image into
nonoverlapping meaningful regions according to human perception, which has
become a classic topic since the early ages of computer vision. A lot of
research has been conducted and has resulted in many applications. However,
while many segmentation algorithms exist, yet there are only a few sparse and
outdated summarizations available, an overview of the recent achievements and
issues is lacking. We aim to provide a comprehensive review of the recent
progress in this field. Covering 180 publications, we give an overview of broad
areas of segmentation topics including not only the classic bottom-up
approaches, but also the recent development in superpixel, interactive methods,
object proposals, semantic image parsing and image cosegmentation. In addition,
we also review the existing influential datasets and evaluation metrics.
Finally, we suggest some design flavors and research directions for future
research in image segmentation.Comment: submitted to Elsevier Journal of Visual Communications and Image
Representatio
Pose for Action - Action for Pose
In this work we propose to utilize information about human actions to improve
pose estimation in monocular videos. To this end, we present a pictorial
structure model that exploits high-level information about activities to
incorporate higher-order part dependencies by modeling action specific
appearance models and pose priors. However, instead of using an additional
expensive action recognition framework, the action priors are efficiently
estimated by our pose estimation framework. This is achieved by starting with a
uniform action prior and updating the action prior during pose estimation. We
also show that learning the right amount of appearance sharing among action
classes improves the pose estimation. We demonstrate the effectiveness of the
proposed method on two challenging datasets for pose estimation and action
recognition with over 80,000 test images.Comment: Accepted to FG-201
Salient Object Detection: A Discriminative Regional Feature Integration Approach
Salient object detection has been attracting a lot of interest, and recently
various heuristic computational models have been designed. In this paper, we
formulate saliency map computation as a regression problem. Our method, which
is based on multi-level image segmentation, utilizes the supervised learning
approach to map the regional feature vector to a saliency score. Saliency
scores across multiple levels are finally fused to produce the saliency map.
The contributions lie in two-fold. One is that we propose a discriminate
regional feature integration approach for salient object detection. Compared
with existing heuristic models, our proposed method is able to automatically
integrate high-dimensional regional saliency features and choose discriminative
ones. The other is that by investigating standard generic region properties as
well as two widely studied concepts for salient object detection, i.e.,
regional contrast and backgroundness, our approach significantly outperforms
state-of-the-art methods on six benchmark datasets. Meanwhile, we demonstrate
that our method runs as fast as most existing algorithms
A Survey on Object Detection in Optical Remote Sensing Images
Object detection in optical remote sensing images, being a fundamental but
challenging problem in the field of aerial and satellite image analysis, plays
an important role for a wide range of applications and is receiving significant
attention in recent years. While enormous methods exist, a deep review of the
literature concerning generic object detection is still lacking. This paper
aims to provide a review of the recent progress in this field. Different from
several previously published surveys that focus on a specific object class such
as building and road, we concentrate on more generic object categories
including, but are not limited to, road, building, tree, vehicle, ship,
airport, urban-area. Covering about 270 publications we survey 1) template
matching-based object detection methods, 2) knowledge-based object detection
methods, 3) object-based image analysis (OBIA)-based object detection methods,
4) machine learning-based object detection methods, and 5) five publicly
available datasets and three standard evaluation metrics. We also discuss the
challenges of current studies and propose two promising research directions,
namely deep learning-based feature representation and weakly supervised
learning-based geospatial object detection. It is our hope that this survey
will be beneficial for the researchers to have better understanding of this
research field.Comment: This manuscript is the accepted version for ISPRS Journal of
Photogrammetry and Remote Sensin
Julia Language in Machine Learning: Algorithms, Applications, and Open Issues
Machine learning is driving development across many fields in science and
engineering. A simple and efficient programming language could accelerate
applications of machine learning in various fields. Currently, the programming
languages most commonly used to develop machine learning algorithms include
Python, MATLAB, and C/C ++. However, none of these languages well balance both
efficiency and simplicity. The Julia language is a fast, easy-to-use, and
open-source programming language that was originally designed for
high-performance computing, which can well balance the efficiency and
simplicity. This paper summarizes the related research work and developments in
the application of the Julia language in machine learning. It first surveys the
popular machine learning algorithms that are developed in the Julia language.
Then, it investigates applications of the machine learning algorithms
implemented with the Julia language. Finally, it discusses the open issues and
the potential future directions that arise in the use of the Julia language in
machine learning.Comment: Published in Computer Science Revie
Bootstrapping Robotic Ecological Perception from a Limited Set of Hypotheses Through Interactive Perception
To solve its task, a robot needs to have the ability to interpret its
perceptions. In vision, this interpretation is particularly difficult and
relies on the understanding of the structure of the scene, at least to the
extent of its task and sensorimotor abilities. A robot with the ability to
build and adapt this interpretation process according to its own tasks and
capabilities would push away the limits of what robots can achieve in a non
controlled environment. A solution is to provide the robot with processes to
build such representations that are not specific to an environment or a
situation. A lot of works focus on objects segmentation, recognition and
manipulation. Defining an object solely on the basis of its visual appearance
is challenging given the wide range of possible objects and environments.
Therefore, current works make simplifying assumptions about the structure of a
scene. Such assumptions reduce the adaptivity of the object extraction process
to the environments in which the assumption holds. To limit such assumptions,
we introduce an exploration method aimed at identifying moveable elements in a
scene without considering the concept of object. By using the interactive
perception framework, we aim at bootstrapping the acquisition process of a
representation of the environment with a minimum of context specific
assumptions. The robotic system builds a perceptual map called relevance map
which indicates the moveable parts of the current scene. A classifier is
trained online to predict the category of each region (moveable or
non-moveable). It is also used to select a region with which to interact, with
the goal of minimizing the uncertainty of the classification. A specific
classifier is introduced to fit these needs: the collaborative mixture models
classifier. The method is tested on a set of scenarios of increasing
complexity, using both simulations and a PR2 robot.Comment: 21 pages, 21 figure
Spatio-Temporal Data Mining: A Survey of Problems and Methods
Large volumes of spatio-temporal data are increasingly collected and studied
in diverse domains including, climate science, social sciences, neuroscience,
epidemiology, transportation, mobile health, and Earth sciences.
Spatio-temporal data differs from relational data for which computational
approaches are developed in the data mining community for multiple decades, in
that both spatial and temporal attributes are available in addition to the
actual measurements/attributes. The presence of these attributes introduces
additional challenges that needs to be dealt with. Approaches for mining
spatio-temporal data have been studied for over a decade in the data mining
community. In this article we present a broad survey of this relatively young
field of spatio-temporal data mining. We discuss different types of
spatio-temporal data and the relevant data mining questions that arise in the
context of analyzing each of these datasets. Based on the nature of the data
mining problem studied, we classify literature on spatio-temporal data mining
into six major categories: clustering, predictive learning, change detection,
frequent pattern mining, anomaly detection, and relationship mining. We discuss
the various forms of spatio-temporal data mining problems in each of these
categories.Comment: Accepted for publication at ACM Computing Survey
An Intelligent System For Effective Forest Fire Detection Using Spatial Data
The explosive growth of spatial data and extensive utilization of spatial
databases emphasize the necessity for the automated discovery of spatial
knowledge. In modern times, spatial data mining has emerged as an area of
voluminous research. Forest fires are a chief environmental concern, causing
economical and ecological damage while endangering human lives across the
world. The fast or early detection of forest fires is a vital element for
controlling such phenomenon. The application of remote sensing is at present a
significant method for forest fires monitoring, particularly in vast and remote
areas. Different methods have been presented by researchers for forest fire
detection. The motivation behind this research is to obtain beneficial
information from images in the forest spatial data and use the same in the
determination of regions at the risk of fires by utilizing Image Processing and
Artificial Intelligence techniques. This paper presents an intelligent system
to detect the presence of forest fires in the forest spatial data using
Artificial Neural Networks. The digital images in the forest spatial data are
converted from RGB to XYZ color space and then segmented by employing
anisotropic diffusion to identify the fire regions. Subsequently, Radial Basis
Function Neural Network is employed in the design of the intelligent system,
which is trained with the color space values of the segmented fire regions.
Extensive experimental assessments on publicly available spatial data
illustrated the efficiency of the proposed system in effectively detecting
forest fires.Comment: IEEE format, International Journal of Computer Science and
Information Security, IJCSIS January 2010, ISSN 1947 5500,
http://sites.google.com/site/ijcsis
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