11,801 research outputs found
Indexing, browsing and searching of digital video
Video is a communications medium that normally brings together moving pictures with a synchronised audio track into a discrete piece or pieces of information. The size of a âpiece â of video can variously be referred to as a frame, a shot, a scene, a clip, a programme or an episode, and these are distinguished by their lengths and by their composition. We shall return to the definition of each of these in section 4 this chapter. In modern society, video is ver
Evaluation campaigns and TRECVid
The TREC Video Retrieval Evaluation (TRECVid) is an
international benchmarking activity to encourage research
in video information retrieval by providing a large test collection, uniform scoring procedures, and a forum for organizations interested in comparing their results. TRECVid completed its fifth annual cycle at the end of 2005 and in 2006 TRECVid will involve almost 70 research organizations, universities and other consortia. Throughout its existence, TRECVid has benchmarked both interactive and automatic/manual searching for shots from within a video
corpus, automatic detection of a variety of semantic and
low-level video features, shot boundary detection and the
detection of story boundaries in broadcast TV news. This
paper will give an introduction to information retrieval (IR) evaluation from both a user and a system perspective, highlighting that system evaluation is by far the most prevalent type of evaluation carried out. We also include a summary of TRECVid as an example of a system evaluation benchmarking campaign and this allows us to discuss whether
such campaigns are a good thing or a bad thing. There are
arguments for and against these campaigns and we present
some of them in the paper concluding that on balance they
have had a very positive impact on research progress
Combining textual and visual information processing for interactive video retrieval: SCHEMA's participation in TRECVID 2004
In this paper, the two different applications based on the Schema Reference System that were developed by the SCHEMA NoE for participation to the search task of TRECVID 2004 are illustrated. The first application, named âSchema-Textâ, is an interactive retrieval application that employs only textual information while the second one, named âSchema-XMâ, is an extension of the former, employing algorithms and
methods for combining textual, visual and higher level information. Two runs for each application were submitted, I A 2 SCHEMA-Text 3, I A 2 SCHEMA-Text 4 for Schema-Text and I A 2 SCHEMA-XM 1, I A 2 SCHEMA-XM 2 for Schema-XM. The comparison of these two applications in terms of retrieval efficiency revealed that the combination of information from different data sources can provide higher efficiency for retrieval systems. Experimental testing additionally revealed that initially performing a text-based query and subsequently proceeding with visual similarity search using one of the returned relevant keyframes as an example image is a good scheme for combining visual and textual information
Interactive searching and browsing of video archives: using text and using image matching
Over the last number of decades much research work has been done in the general area of video and audio analysis. Initially the applications driving this included capturing video in digital form and then being able to store, transmit
and render it, which involved a large effort to develop compression and encoding standards. The technology needed to do all this is now easily available and cheap, with applications of digital video processing now commonplace,
ranging from CCTV (Closed Circuit TV) for security, to home capture of broadcast TV on home DVRs for personal viewing.
One consequence of the development in technology for creating, storing and distributing digital video is that there has been a huge increase in the volume of digital video, and this in turn has created a need for techniques to allow effective management of this video, and by that we mean content management. In the BBC, for example, the archives department receives approximately 500,000 queries per year and has over 350,000 hours of content in its library. Having huge archives of video information is hardly any benefit if we have no effective means of being able to locate video clips which are of relevance to whatever our information needs may be. In this chapter we report our work on developing two specific retrieval and browsing tools for digital video information. Both of these are based on an analysis of the captured video for the purpose of automatically structuring into shots or higher level semantic units like TV news stories. Some also include analysis of the video for the automatic detection of features such as the presence or absence of faces. Both include some elements of searching, where a user specifies a query or information need, and browsing, where a user is allowed to browse through sets of retrieved video shots. We support the presentation of these tools with illustrations of actual video retrieval systems developed and working on hundreds of hours of video content
The Atmospheric Monitoring System of the JEM-EUSO Space Mission
An Atmospheric Monitoring System (AMS) is a mandatory and key device of a
space-based mission which aims to detect Ultra-High Energy Cosmic Rays (UHECR)
and Extremely-High Energy Cosmic Rays (EHECR) from Space. JEM-EUSO has a
dedicated atmospheric monitoring system that plays a fundamental role in our
understanding of the atmospheric conditions in the Field of View (FoV) of the
telescope. Our AMS consists of a very challenging space infrared camera and a
LIDAR device, that are being fully designed with space qualification to fulfil
the scientific requirements of this space mission. The AMS will provide
information of the cloud cover in the FoV of JEM-EUSO, as well as measurements
of the cloud top altitudes with an accuracy of 500 m and the optical depth
profile of the atmosphere transmittance in the direction of each air shower
with an accuracy of 0.15 degree and a resolution of 500 m. This will ensure
that the energy of the primary UHECR and the depth of maximum development of
the EAS ( Extensive Air Shower) are measured with an accuracy better than 30\%
primary energy and 120 depth of maximum development for EAS occurring
either in clear sky or with the EAS depth of maximum development above
optically thick cloud layers. Moreover a very novel radiometric retrieval
technique considering the LIDAR shots as calibration points, that seems to be
the most promising retrieval algorithm is under development to infer the Cloud
Top Height (CTH) of all kind of clouds, thick and thin clouds in the FoV of the
JEM-EUSO space telescope
The TRECVID 2007 BBC rushes summarization evaluation pilot
This paper provides an overview of a pilot evaluation of
video summaries using rushes from several BBC dramatic series. It was carried out under the auspices of TRECVID.
Twenty-two research teams submitted video summaries of
up to 4% duration, of 42 individual rushes video files aimed
at compressing out redundant and insignificant material.
The output of two baseline systems built on straightforward
content reduction techniques was contributed by Carnegie
Mellon University as a control. Procedures for developing
ground truth lists of important segments from each video
were developed at Dublin City University and applied to
the BBC video. At NIST each summary was judged by
three humans with respect to how much of the ground truth
was included, how easy the summary was to understand,
and how much repeated material the summary contained.
Additional objective measures included: how long it took
the system to create the summary, how long it took the assessor to judge it against the ground truth, and what the
summary's duration was. Assessor agreement on finding desired segments averaged 78% and results indicate that while it is difficult to exceed the performance of baselines, a few systems did
Collaborative video searching on a tabletop
Almost all system and application design for multimedia systems is based around a single user working in isolation to perform some task yet much of the work for which we use computers to help us, is based on working collaboratively with colleagues. Groupware systems do support user collaboration but typically this is supported through software and users still physically work independently. Tabletop systems, such as the DiamondTouch from MERL, are interface devices which support direct user collaboration on a tabletop. When a tabletop is used as the interface for a multimedia system, such as a video search system, then this kind of direct collaboration raises many questions for system design. In this paper we present a tabletop system for supporting a pair of users in a video search task and we evaluate the system not only in terms of search performance but also in terms of userâuser interaction and how different user personalities within each pair of searchers impacts search performance and user interaction. Incorporating the user into the system evaluation as we have done here reveals several interesting results and has important ramifications for the design of a multimedia search system
The FĂschlĂĄr-News-Stories system: personalised access to an archive of TV news
The âFĂschlĂĄrâ systems are a family of tools for capturing, analysis, indexing, browsing, searching and summarisation of digital video information. FĂschlĂĄr-News-Stories, described in this paper, is one of those systems, and provides access to a growing archive of broadcast TV news. FĂschlĂĄr-News-Stories has several notable features including the fact that it automatically records TV news and segments a broadcast news program into stories, eliminating advertisements and credits at the start/end of the broadcast. FĂschlĂĄr-News-Stories supports access to individual stories via calendar lookup, text search through closed captions, automatically-generated links between related stories, and personalised access using a personalisation and recommender system based on collaborative filtering. Access to individual news stories is supported either by browsing keyframes with synchronised closed captions, or by playback of the recorded video. One strength of the FĂschlĂĄr-News-Stories system is that it is actually used, in practice, daily, to access news. Several aspects of the FĂschlĂĄr systems have been published before, bit in this paper we give a summary of the FĂschlĂĄr-News-Stories system in operation by following a scenario in which it is used and also outlining how the underlying system realises the functions it offers
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