45,222 research outputs found
Using video objects and relevance feedback in video retrieval
Video retrieval is mostly based on using text from dialogue and this remains the most signi¯cant component, despite progress in other aspects. One problem with this is when a searcher wants to locate video based on what is appearing in the video rather than what is being spoken about. Alternatives such as automatically-detected features and image-based keyframe matching can be used, though these still need further improvement in quality. One other modality for video retrieval is based on segmenting objects from video and allowing end users to use these as part of querying. This uses similarity between query objects and objects from video, and in theory allows retrieval based on what is actually appearing on-screen. The main hurdles to greater use of this are the overhead of object segmentation on large amounts of video and the issue of whether we can actually achieve effective object-based retrieval.
We describe a system to support object-based video retrieval where a user selects example video objects as part of the query. During a search a user builds up a set of these which are matched against objects previously segmented from a video library. This match is based on MPEG-7 Dominant Colour, Shape Compaction and Texture Browsing descriptors. We use a user-driven semi-automated segmentation process to segment the video archive which is very accurate and is faster than conventional video annotation
Dublin City University video track experiments for TREC 2002
Dublin City University participated in the Feature Extraction task and the Search task of the TREC-2002 Video
Track. In the Feature Extraction task, we submitted 3 features: Face, Speech, and Music. In the Search task, we
developed an interactive video retrieval system, which incorporated the 40 hours of the video search test collection and supported user searching using our own feature extraction data along with the donated feature data and ASR transcript from other Video Track groups. This video retrieval system allows a user to specify a query based on the 10 features and ASR transcript, and the query result is a ranked list of videos that can be further browsed at the shot level. To evaluate the usefulness of the feature-based query, we have developed a second system interface that
provides only ASR transcript-based querying, and we conducted an experiment with 12 test users to compare these 2 systems. Results were submitted to NIST and we are currently conducting further analysis of user performance with these 2 systems
An affect-based video retrieval system with open vocabulary querying
Content-based video retrieval systems (CBVR) are creating
new search and browse capabilities using metadata describing significant features of the data. An often overlooked aspect of human interpretation of multimedia data is the affective dimension. Incorporating affective information into multimedia metadata can potentially enable search using
this alternative interpretation of multimedia content. Recent work has described methods to automatically assign affective labels to multimedia data using various approaches. However, the subjective and imprecise nature of affective labels makes it difficult to bridge the semantic gap between system-detected labels and user expression of information requirements in multimedia retrieval. We present a novel affect-based video retrieval system incorporating an open-vocabulary query stage based on WordNet enabling search using an unrestricted query vocabulary. The system performs automatic annotation of video data with labels of well
defined affective terms. In retrieval annotated documents are ranked using the standard Okapi retrieval model based on open-vocabulary text queries. We present experimental results examining the behaviour of the system for retrieval of a collection of automatically annotated feature films of different genres. Our results indicate that affective annotation can potentially provide useful augmentation to more traditional objective content description in multimedia retrieval
Video Stream Retrieval of Unseen Queries using Semantic Memory
Retrieval of live, user-broadcast video streams is an under-addressed and
increasingly relevant challenge. The on-line nature of the problem requires
temporal evaluation and the unforeseeable scope of potential queries motivates
an approach which can accommodate arbitrary search queries. To account for the
breadth of possible queries, we adopt a no-example approach to query retrieval,
which uses a query's semantic relatedness to pre-trained concept classifiers.
To adapt to shifting video content, we propose memory pooling and memory
welling methods that favor recent information over long past content. We
identify two stream retrieval tasks, instantaneous retrieval at any particular
time and continuous retrieval over a prolonged duration, and propose means for
evaluating them. Three large scale video datasets are adapted to the challenge
of stream retrieval. We report results for our search methods on the new stream
retrieval tasks, as well as demonstrate their efficacy in a traditional,
non-streaming video task.Comment: Presented at BMVC 2016, British Machine Vision Conference, 201
Circulant temporal encoding for video retrieval and temporal alignment
We address the problem of specific video event retrieval. Given a query video
of a specific event, e.g., a concert of Madonna, the goal is to retrieve other
videos of the same event that temporally overlap with the query. Our approach
encodes the frame descriptors of a video to jointly represent their appearance
and temporal order. It exploits the properties of circulant matrices to
efficiently compare the videos in the frequency domain. This offers a
significant gain in complexity and accurately localizes the matching parts of
videos. The descriptors can be compressed in the frequency domain with a
product quantizer adapted to complex numbers. In this case, video retrieval is
performed without decompressing the descriptors. We also consider the temporal
alignment of a set of videos. We exploit the matching confidence and an
estimate of the temporal offset computed for all pairs of videos by our
retrieval approach. Our robust algorithm aligns the videos on a global timeline
by maximizing the set of temporally consistent matches. The global temporal
alignment enables synchronous playback of the videos of a given scene
Multilevel Language and Vision Integration for Text-to-Clip Retrieval
We address the problem of text-based activity retrieval in video. Given a
sentence describing an activity, our task is to retrieve matching clips from an
untrimmed video. To capture the inherent structures present in both text and
video, we introduce a multilevel model that integrates vision and language
features earlier and more tightly than prior work. First, we inject text
features early on when generating clip proposals, to help eliminate unlikely
clips and thus speed up processing and boost performance. Second, to learn a
fine-grained similarity metric for retrieval, we use visual features to
modulate the processing of query sentences at the word level in a recurrent
neural network. A multi-task loss is also employed by adding query
re-generation as an auxiliary task. Our approach significantly outperforms
prior work on two challenging benchmarks: Charades-STA and ActivityNet
Captions.Comment: AAAI 201
Query generation from multiple media examples
This paper exploits an unified media document representation called feature terms for query generation from multiple media examples, e.g. images. A feature term refers to a value interval of a media feature. A media document is therefore represented by a frequency vector about feature term appearance. This approach (1) facilitates feature accumulation from multiple examples; (2) enables the exploration of text-based retrieval models for multimedia retrieval. Three statistical criteria, minimised chi-squared, minimised AC/DC rate and maximised entropy, are proposed to extract feature terms from a given media document collection. Two textual ranking functions, KL divergence and a BM25-like retrieval model, are adapted to estimate media document relevance. Experiments on the Corel photo collection and the TRECVid 2006 collection show the effectiveness of feature term based query in image and video retrieval
Tree-based Text-Vision BERT for Video Search in Baidu Video Advertising
The advancement of the communication technology and the popularity of the
smart phones foster the booming of video ads. Baidu, as one of the leading
search engine companies in the world, receives billions of search queries per
day. How to pair the video ads with the user search is the core task of Baidu
video advertising. Due to the modality gap, the query-to-video retrieval is
much more challenging than traditional query-to-document retrieval and
image-to-image search. Traditionally, the query-to-video retrieval is tackled
by the query-to-title retrieval, which is not reliable when the quality of
tiles are not high. With the rapid progress achieved in computer vision and
natural language processing in recent years, content-based search methods
becomes promising for the query-to-video retrieval. Benefited from pretraining
on large-scale datasets, some visionBERT methods based on cross-modal attention
have achieved excellent performance in many vision-language tasks not only in
academia but also in industry. Nevertheless, the expensive computation cost of
cross-modal attention makes it impractical for large-scale search in industrial
applications. In this work, we present a tree-based combo-attention network
(TCAN) which has been recently launched in Baidu's dynamic video advertising
platform. It provides a practical solution to deploy the heavy cross-modal
attention for the large-scale query-to-video search. After launching tree-based
combo-attention network, click-through rate gets improved by 2.29\% and
conversion rate get improved by 2.63\%.Comment: This revision is based on a manuscript submitted in October 2020, to
ICDE 2021. We thank the Program Committee for their valuable comment
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