Introduction
TRECVID 2004 Keyframes and Transcripts was developed as
a collaborative effort between researchers at
LDC, NIST, LIMSI-CNRS,
and Dublin City University.
TREC Video Retrieval Evaluation (TRECVID) is sponsored by the
National Institute of Standards and Technology (NIST) to promote
progress in content-based retrieval from digital video via open,
metrics-based evaluation. The keyframes in this release were
extracted for use in the NIST TRECVID 2004 Evaluation.
TRECVID is a laboratory-style evaluation that attempts to model real
world situations or significant component tasks involved in such
situations. In 2004 there were four main tasks with associated tests:
-
shot boundary determination
-
story segmentation
-
high-level feature extraction
-
search (interactive and manual)
For a detailed description of the TRECVID Evaluation Tasks, please
refer to the
NIST
TRECVID 2004 Evaluation Description.
Data
The source data includes approximately 70
hours of English language broadcast
programming collected by LDC in 1998 from ABC
("World News Tonight") and CNN
("CNN Headline News").
Shots are fundamental units of video, useful for higher-level processing.
To create the master list of shots, the video was segmented. The results of
this pass are called subshots. Because the master shot reference is designed
for use in manual assessment, a second pass over the segmentation was made to
create the master shots of at least 2 seconds in length. These master shots
are the ones used in submitting results for the feature and search tasks in
the evaluation. In the second pass, starting at the beginning of each file,
the subshots were aggregated, if necessary, until the current shot was at least
2 seconds in duration, at which point the aggregation began anew with the next
subshot.
The keyframes were selected by going to the middle frame of the shot
boundary, then parsing left and right of that frame to locate the
nearest I-Frame. This then became the keyframe and was extracted.
Keyframes have been provided at both the subshot (NRKF) and master
shot (RKF) levels.
In a small number of cases (all of them subshots) there was no I-Frame within
the subshot boundaries. When this occurred, the middle frame was selected. There
is one anomaly: at the end of the first video in the test collection, a subshot
occurs outside a master shot.)
The emphasis in the common shot boundary reference is on the shots,
not the transitions. The shots are contiguous. There are no gaps
between them. They do not overlap. The media time format is based on
the Gregorian day time (ISO 8601) norm. Fractions are defined by
counting pre-specified fractions of a second.
Sample
Samples of data available in this corpus:
Keyframe (video still)
Shots metadata (mp7 markup)
Subshot metadata
Transcript
Tokenized transcript
Updates
No updates are available at this time.
Content Copyright
Portions © 1998 American Broadcasting Company, © 1998 Cable
News Network, LP, LLLP, © 1998, 2003, 2007, 2010 Trustees of the
University of Pennsylvania |