1,356 research outputs found
Knowledge-rich Image Gist Understanding Beyond Literal Meaning
We investigate the problem of understanding the message (gist) conveyed by
images and their captions as found, for instance, on websites or news articles.
To this end, we propose a methodology to capture the meaning of image-caption
pairs on the basis of large amounts of machine-readable knowledge that has
previously been shown to be highly effective for text understanding. Our method
identifies the connotation of objects beyond their denotation: where most
approaches to image understanding focus on the denotation of objects, i.e.,
their literal meaning, our work addresses the identification of connotations,
i.e., iconic meanings of objects, to understand the message of images. We view
image understanding as the task of representing an image-caption pair on the
basis of a wide-coverage vocabulary of concepts such as the one provided by
Wikipedia, and cast gist detection as a concept-ranking problem with
image-caption pairs as queries. To enable a thorough investigation of the
problem of gist understanding, we produce a gold standard of over 300
image-caption pairs and over 8,000 gist annotations covering a wide variety of
topics at different levels of abstraction. We use this dataset to
experimentally benchmark the contribution of signals from heterogeneous
sources, namely image and text. The best result with a Mean Average Precision
(MAP) of 0.69 indicate that by combining both dimensions we are able to better
understand the meaning of our image-caption pairs than when using language or
vision information alone. We test the robustness of our gist detection approach
when receiving automatically generated input, i.e., using automatically
generated image tags or generated captions, and prove the feasibility of an
end-to-end automated process
TagBook: A Semantic Video Representation without Supervision for Event Detection
We consider the problem of event detection in video for scenarios where only
few, or even zero examples are available for training. For this challenging
setting, the prevailing solutions in the literature rely on a semantic video
representation obtained from thousands of pre-trained concept detectors.
Different from existing work, we propose a new semantic video representation
that is based on freely available social tagged videos only, without the need
for training any intermediate concept detectors. We introduce a simple
algorithm that propagates tags from a video's nearest neighbors, similar in
spirit to the ones used for image retrieval, but redesign it for video event
detection by including video source set refinement and varying the video tag
assignment. We call our approach TagBook and study its construction,
descriptiveness and detection performance on the TRECVID 2013 and 2014
multimedia event detection datasets and the Columbia Consumer Video dataset.
Despite its simple nature, the proposed TagBook video representation is
remarkably effective for few-example and zero-example event detection, even
outperforming very recent state-of-the-art alternatives building on supervised
representations.Comment: accepted for publication as a regular paper in the IEEE Transactions
on Multimedi
Multimedia information technology and the annotation of video
The state of the art in multimedia information technology has not progressed to the point where a single solution is available to meet all reasonable needs of documentalists and users of video archives. In general, we do not have an optimistic view of the usability of new technology in this domain, but digitization and digital power can be expected to cause a small revolution in the area of video archiving. The volume of data leads to two views of the future: on the pessimistic side, overload of data will cause lack of annotation capacity, and on the optimistic side, there will be enough data from which to learn selected concepts that can be deployed to support automatic annotation. At the threshold of this interesting era, we make an attempt to describe the state of the art in technology. We sample the progress in text, sound, and image processing, as well as in machine learning
Semantic multimedia analysis using knowledge and context
PhDThe difficulty of semantic multimedia analysis can be attributed to the
extended diversity in form and appearance exhibited by the majority of
semantic concepts and the difficulty to express them using a finite number
of patterns. In meeting this challenge there has been a scientific debate
on whether the problem should be addressed from the perspective of using
overwhelming amounts of training data to capture all possible instantiations
of a concept, or from the perspective of using explicit knowledge about
the concepts’ relations to infer their presence. In this thesis we address
three problems of pattern recognition and propose solutions that combine
the knowledge extracted implicitly from training data with the knowledge
provided explicitly in structured form. First, we propose a BNs modeling
approach that defines a conceptual space where both domain related evi-
dence and evidence derived from content analysis can be jointly considered
to support or disprove a hypothesis. The use of this space leads to sig-
nificant gains in performance compared to analysis methods that can not
handle combined knowledge. Then, we present an unsupervised method
that exploits the collective nature of social media to automatically obtain
large amounts of annotated image regions. By proving that the quality of
the obtained samples can be almost as good as manually annotated images
when working with large datasets, we significantly contribute towards scal-
able object detection. Finally, we introduce a method that treats images,
visual features and tags as the three observable variables of an aspect model
and extracts a set of latent topics that incorporates the semantics of both
visual and tag information space. By showing that the cross-modal depen-
dencies of tagged images can be exploited to increase the semantic capacity
of the resulting space, we advocate the use of all existing information facets
in the semantic analysis of social media
Automatic Understanding of Image and Video Advertisements
There is more to images than their objective physical content: for example,
advertisements are created to persuade a viewer to take a certain action. We
propose the novel problem of automatic advertisement understanding. To enable
research on this problem, we create two datasets: an image dataset of 64,832
image ads, and a video dataset of 3,477 ads. Our data contains rich annotations
encompassing the topic and sentiment of the ads, questions and answers
describing what actions the viewer is prompted to take and the reasoning that
the ad presents to persuade the viewer ("What should I do according to this ad,
and why should I do it?"), and symbolic references ads make (e.g. a dove
symbolizes peace). We also analyze the most common persuasive strategies ads
use, and the capabilities that computer vision systems should have to
understand these strategies. We present baseline classification results for
several prediction tasks, including automatically answering questions about the
messages of the ads.Comment: To appear in CVPR 2017; data available on
http://cs.pitt.edu/~kovashka/ad
Exploring Annotation-free Image Captioning with Retrieval-augmented Pseudo Sentence Generation
Training an image captioner without annotated image-sentence pairs has gained
traction in recent years. Previous approaches can be categorized into two
strategies: crawling sentences from mismatching corpora and aligning them with
the given images as pseudo annotations, or pre-training the captioner using
external image-text pairs. However, the aligning setting seems to reach its
performance limit due to the quality problem of pairs, and pre-training
requires significant computational resources. To address these challenges, we
propose a new strategy ``LPM + retrieval-augmented learning" where the prior
knowledge from large pre-trained models (LPMs) is leveraged as supervision, and
a retrieval process is integrated to further reinforce its effectiveness.
Specifically, we introduce Retrieval-augmented Pseudo Sentence Generation
(RaPSG), which adopts an efficient approach to retrieve highly relevant short
region descriptions from the mismatching corpora and use them to generate a
variety of pseudo sentences with distinct representations as well as high
quality via LPMs. In addition, a fluency filter and a CLIP-guided training
objective are further introduced to facilitate model optimization. Experimental
results demonstrate that our method surpasses the SOTA pre-training model
(Flamingo3B) by achieving a CIDEr score of 78.1 (+5.1) while utilizing only
0.3% of its trainable parameters (1.3B VS 33M). Importantly, our approach
eliminates the need of computationally expensive pre-training processes on
external datasets (e.g., the requirement of 312M image-text pairs for
Flamingo3B). We further show that with a simple extension, the generated pseudo
sentences can be deployed as weak supervision to boost the 1% semi-supervised
image caption benchmark up to 93.4 CIDEr score (+8.9) which showcases the
versatility and effectiveness of our approach.Comment: 10 pages 5 figure
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