40,787 research outputs found
DecideNet: Counting Varying Density Crowds Through Attention Guided Detection and Density Estimation
In real-world crowd counting applications, the crowd densities vary greatly
in spatial and temporal domains. A detection based counting method will
estimate crowds accurately in low density scenes, while its reliability in
congested areas is downgraded. A regression based approach, on the other hand,
captures the general density information in crowded regions. Without knowing
the location of each person, it tends to overestimate the count in low density
areas. Thus, exclusively using either one of them is not sufficient to handle
all kinds of scenes with varying densities. To address this issue, a novel
end-to-end crowd counting framework, named DecideNet (DEteCtIon and Density
Estimation Network) is proposed. It can adaptively decide the appropriate
counting mode for different locations on the image based on its real density
conditions. DecideNet starts with estimating the crowd density by generating
detection and regression based density maps separately. To capture inevitable
variation in densities, it incorporates an attention module, meant to
adaptively assess the reliability of the two types of estimations. The final
crowd counts are obtained with the guidance of the attention module to adopt
suitable estimations from the two kinds of density maps. Experimental results
show that our method achieves state-of-the-art performance on three challenging
crowd counting datasets.Comment: CVPR 201
A framework for evaluating stereo-based pedestrian detection techniques
Automated pedestrian detection, counting, and tracking have received significant attention in the computer vision community of late. As such, a variety of techniques have been investigated using both traditional 2-D computer vision techniques and, more recently, 3-D stereo information. However, to date, a quantitative assessment of the performance of stereo-based pedestrian detection has been problematic, mainly due to the lack of standard stereo-based test data and an agreed methodology for carrying out the evaluation. This has forced researchers into making subjective comparisons between competing approaches. In this paper, we propose a framework for the quantitative evaluation of a short-baseline stereo-based pedestrian detection system. We provide freely available synthetic and real-world test data and recommend a set of evaluation metrics. This allows researchers to benchmark systems, not only with respect to other stereo-based approaches, but also with more traditional 2-D approaches. In order to illustrate its usefulness, we demonstrate the application of this framework to evaluate our own recently proposed technique for pedestrian detection and tracking
Single-Shot Multi-Person 3D Pose Estimation From Monocular RGB
We propose a new single-shot method for multi-person 3D pose estimation in
general scenes from a monocular RGB camera. Our approach uses novel
occlusion-robust pose-maps (ORPM) which enable full body pose inference even
under strong partial occlusions by other people and objects in the scene. ORPM
outputs a fixed number of maps which encode the 3D joint locations of all
people in the scene. Body part associations allow us to infer 3D pose for an
arbitrary number of people without explicit bounding box prediction. To train
our approach we introduce MuCo-3DHP, the first large scale training data set
showing real images of sophisticated multi-person interactions and occlusions.
We synthesize a large corpus of multi-person images by compositing images of
individual people (with ground truth from mutli-view performance capture). We
evaluate our method on our new challenging 3D annotated multi-person test set
MuPoTs-3D where we achieve state-of-the-art performance. To further stimulate
research in multi-person 3D pose estimation, we will make our new datasets, and
associated code publicly available for research purposes.Comment: International Conference on 3D Vision (3DV), 201
Improving object detection by exploiting semantic relations between objects
En col·laboració amb la Universitat de Barcelona (UB) i la Universitat Rovira i Virgili (URV)Object detection is a fundamental and challenging problem in computer vision.
Detecting the objects visible in an image can give us a good understanding and description of
the image. The extracted information can later be used to improve the results of other
computer vision tasks like activity recognition, content-based image retrieval, scene
recognition and more.
As technology and internet connection are becoming more accessible, billions of
people upload photos and videos every day. In order to make use of this enormous amount of
data we need to be able to extract information from these images in a quick and yet reliable
way. Convolutional neural networks (CNN) have made possible enormous progresses in
object detection and classification in recent years and have already established themself as the
state of the art approach for these problems. In this work, we try to improve object detection
performances by employing a CNN approach able to exploit object co-occurrences in natural
images. Typically, real world scenes often exhibit a coherent composition of object in terms of
co-occurrence probability. For instance, in a restaurant we typically see dishes, bottles and
glasses. We aim at using this type of knowledge as a cue for disambiguating object labels in a
detection task
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