83,953 research outputs found
The scene superiority effect: object recognition in the context of natural scenes
Four experiments investigate the effect of background scene semantics on object recognition. Although past research has found that semantically consistent scene backgrounds can facilitate recognition of a target object, these claims have been challenged as the result of post-perceptual response bias rather than the perceptual processes of object recognition itself. The current study takes advantage of a paradigm from linguistic processing known as the Word Superiority Effect. Humans can better discriminate letters (e.g., D vs. K) in the context of a word (WORD vs. WORK) than in a non-word context (e.g., WROD vs. WROK) even when the context is non-predictive of the target identity. We apply this paradigm to objects in natural scenes, having subjects discriminate between objects in the context of scenes. Because the target objects were equally semantically consistent with any given scene and could appear in either semantically consistent or inconsistent contexts with equal probability, response bias could not lead to an apparent improvement in object recognition. The current study found a benefit to object recognition from semantically consistent backgrounds, and the effect appeared to be modulated by awareness of background scene semantics
Toward a Taxonomy and Computational Models of Abnormalities in Images
The human visual system can spot an abnormal image, and reason about what
makes it strange. This task has not received enough attention in computer
vision. In this paper we study various types of atypicalities in images in a
more comprehensive way than has been done before. We propose a new dataset of
abnormal images showing a wide range of atypicalities. We design human subject
experiments to discover a coarse taxonomy of the reasons for abnormality. Our
experiments reveal three major categories of abnormality: object-centric,
scene-centric, and contextual. Based on this taxonomy, we propose a
comprehensive computational model that can predict all different types of
abnormality in images and outperform prior arts in abnormality recognition.Comment: To appear in the Thirtieth AAAI Conference on Artificial Intelligence
(AAAI 2016
Place Categorization and Semantic Mapping on a Mobile Robot
In this paper we focus on the challenging problem of place categorization and
semantic mapping on a robot without environment-specific training. Motivated by
their ongoing success in various visual recognition tasks, we build our system
upon a state-of-the-art convolutional network. We overcome its closed-set
limitations by complementing the network with a series of one-vs-all
classifiers that can learn to recognize new semantic classes online. Prior
domain knowledge is incorporated by embedding the classification system into a
Bayesian filter framework that also ensures temporal coherence. We evaluate the
classification accuracy of the system on a robot that maps a variety of places
on our campus in real-time. We show how semantic information can boost robotic
object detection performance and how the semantic map can be used to modulate
the robot's behaviour during navigation tasks. The system is made available to
the community as a ROS module
Seeing Behind the Camera: Identifying the Authorship of a Photograph
We introduce the novel problem of identifying the photographer behind a
photograph. To explore the feasibility of current computer vision techniques to
address this problem, we created a new dataset of over 180,000 images taken by
41 well-known photographers. Using this dataset, we examined the effectiveness
of a variety of features (low and high-level, including CNN features) at
identifying the photographer. We also trained a new deep convolutional neural
network for this task. Our results show that high-level features greatly
outperform low-level features. We provide qualitative results using these
learned models that give insight into our method's ability to distinguish
between photographers, and allow us to draw interesting conclusions about what
specific photographers shoot. We also demonstrate two applications of our
method.Comment: Dataset downloadable at http://www.cs.pitt.edu/~chris/photographer To
Appear in CVPR 201
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