104 research outputs found
Event detection in field sports video using audio-visual features and a support vector machine
In this paper, we propose a novel audio-visual feature-based framework for event detection in broadcast video of multiple different field sports. Features indicating significant events are selected and robust detectors built. These features are rooted in characteristics common to all genres of field sports. The evidence gathered by the feature detectors is combined by means of a support vector machine, which infers the occurrence of an event based on a model generated during a training phase. The system is tested generically across multiple genres of field sports including soccer, rugby, hockey, and Gaelic football and the results suggest that high event retrieval and content rejection statistics are achievable
Highly efficient low-level feature extraction for video representation and retrieval.
PhDWitnessing the omnipresence of digital video media, the research community has
raised the question of its meaningful use and management. Stored in immense
multimedia databases, digital videos need to be retrieved and structured in an
intelligent way, relying on the content and the rich semantics involved. Current
Content Based Video Indexing and Retrieval systems face the problem of the semantic
gap between the simplicity of the available visual features and the richness of user
semantics.
This work focuses on the issues of efficiency and scalability in video indexing and
retrieval to facilitate a video representation model capable of semantic annotation. A
highly efficient algorithm for temporal analysis and key-frame extraction is developed.
It is based on the prediction information extracted directly from the compressed domain
features and the robust scalable analysis in the temporal domain. Furthermore,
a hierarchical quantisation of the colour features in the descriptor space is presented.
Derived from the extracted set of low-level features, a video representation model that
enables semantic annotation and contextual genre classification is designed.
Results demonstrate the efficiency and robustness of the temporal analysis algorithm
that runs in real time maintaining the high precision and recall of the detection task.
Adaptive key-frame extraction and summarisation achieve a good overview of the
visual content, while the colour quantisation algorithm efficiently creates hierarchical
set of descriptors. Finally, the video representation model, supported by the genre
classification algorithm, achieves excellent results in an automatic annotation system by
linking the video clips with a limited lexicon of related keywords
Scene extraction in motion pictures
This paper addresses the challenge of bridging the semantic gap between the rich meaning users desire when they query to locate and browse media and the shallowness of media descriptions that can be computed in today\u27s content management systems. To facilitate high-level semantics-based content annotation and interpretation, we tackle the problem of automatic decomposition of motion pictures into meaningful story units, namely scenes. Since a scene is a complicated and subjective concept, we first propose guidelines from fill production to determine when a scene change occurs. We then investigate different rules and conventions followed as part of Fill Grammar that would guide and shape an algorithmic solution for determining a scene. Two different techniques using intershot analysis are proposed as solutions in this paper. In addition, we present different refinement mechanisms, such as film-punctuation detection founded on Film Grammar, to further improve the results. These refinement techniques demonstrate significant improvements in overall performance. Furthermore, we analyze errors in the context of film-production techniques, which offer useful insights into the limitations of our method
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Content-based Digital Video Processing. Digital Videos Segmentation, Retrieval and Interpretation.
Recent research approaches in semantics based video content analysis require shot boundary detection as the first step to divide video sequences into sections. Furthermore, with the advances in networking and computing capability, efficient retrieval of multimedia data has become an important issue. Content-based retrieval technologies have been widely implemented to protect intellectual property rights (IPR). In addition, automatic recognition of highlights from videos is a fundamental and challenging problem for content-based indexing and retrieval applications.
In this thesis, a paradigm is proposed to segment, retrieve and interpret digital videos. Five algorithms are presented to solve the video segmentation task. Firstly, a simple shot cut detection algorithm is designed for real-time implementation. Secondly, a systematic method is proposed for shot detection using content-based rules and FSM (finite state machine). Thirdly, the shot detection is implemented using local and global indicators. Fourthly, a context awareness approach is proposed to detect shot boundaries. Fifthly, a fuzzy logic method is implemented for shot detection. Furthermore, a novel analysis approach is presented for the detection of video copies. It is robust to complicated distortions and capable of locating the copy of segments inside original videos. Then,
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objects and events are extracted from MPEG Sequences for Video Highlights Indexing and Retrieval. Finally, a human fighting detection algorithm is proposed for movie annotation
Automatic Summarization of Soccer Highlights Using Audio-visual Descriptors
Automatic summarization generation of sports video content has been object of
great interest for many years. Although semantic descriptions techniques have
been proposed, many of the approaches still rely on low-level video descriptors
that render quite limited results due to the complexity of the problem and to
the low capability of the descriptors to represent semantic content. In this
paper, a new approach for automatic highlights summarization generation of
soccer videos using audio-visual descriptors is presented. The approach is
based on the segmentation of the video sequence into shots that will be further
analyzed to determine its relevance and interest. Of special interest in the
approach is the use of the audio information that provides additional
robustness to the overall performance of the summarization system. For every
video shot a set of low and mid level audio-visual descriptors are computed and
lately adequately combined in order to obtain different relevance measures
based on empirical knowledge rules. The final summary is generated by selecting
those shots with highest interest according to the specifications of the user
and the results of relevance measures. A variety of results are presented with
real soccer video sequences that prove the validity of the approach
Video Shot Boundary Detection Using Generalized Eigenvalue Decomposition and Gaussian Transition Detection
Shot boundary detection is the first step of the video analysis, summarization and retrieval. In this paper, we propose a novel shot boundary detection algorithm using Generalized Eigenvalue Decomposition (GED) and modeling of gradual transitions by Gaussian functions. Especially, we focus on the challenges of detecting the gradual shots and extracting appropriate spatio-temporal features, which have effects on the ability of algorithm to detect shot boundaries efficiently. We derive a theorem that discuss about some new features of GED which could be used in the video processing algorithms. Our innovative explanation utilizes this theorem in the defining of new distance metric in Eigen space for comparing video frames. The distance function has abrupt changes in hard cut transitions and semi-Gaussian behavior in gradual transitions. The algorithm detects the transitions by analyzing this distance function. Finally we report the experimental results using large-scale test sets provided by the TRECVID 2006 which has evaluations for hard cut and gradual shot boundary detection
A new audio-visual analysis approach and tools for parsing colonoscopy videos
Colonoscopy is an important screening tool for colorectal cancer. During a colonoscopic procedure, a tiny video camera at the tip of the endoscope generates a video signal of the internal mucosa of the colon. The video data are displayed on a monitor for real-time analysis by the endoscopist. We call videos captured from colonoscopic procedures colonoscopy videos. Because these videos possess unique characteristics, new types of semantic units and parsing techniques are required. In this paper, we introduce a new analysis approach that includes (a) a new definition of semantic unit - scene (a segment of visual and audio data that correspond to an endoscopic segment of the colon); (b) a novel scene segmentation algorithm using audio and visual analysis to recognize scene boundaries. We design a prototype system to implement the proposed approach. This system also provides the tools for video/image browsing. The tools enable the users to quickly locate and browse scenes of interest. Experiments on real colonoscopy videos show the effectiveness of our algorithms. The proposed techniques and software are useful (1) for post-procedure reviews, (2) for developing an effective content-based retrieval system for colonoscopy videos to facilitate endoscopic research and education, and (3) for development of a systematic approach to assess endoscopists\u27 procedural skills
A COMPUTATION METHOD/FRAMEWORK FOR HIGH LEVEL VIDEO CONTENT ANALYSIS AND SEGMENTATION USING AFFECTIVE LEVEL INFORMATION
VIDEO segmentation facilitates e±cient video indexing and navigation in large
digital video archives. It is an important process in a content-based video
indexing and retrieval (CBVIR) system. Many automated solutions performed seg-
mentation by utilizing information about the \facts" of the video. These \facts"
come in the form of labels that describe the objects which are captured by the cam-
era. This type of solutions was able to achieve good and consistent results for some
video genres such as news programs and informational presentations. The content
format of this type of videos is generally quite standard, and automated solutions
were designed to follow these format rules. For example in [1], the presence of news
anchor persons was used as a cue to determine the start and end of a meaningful
news segment.
The same cannot be said for video genres such as movies and feature films.
This is because makers of this type of videos utilized different filming techniques to
design their videos in order to elicit certain affective response from their targeted
audience. Humans usually perform manual video segmentation by trying to relate
changes in time and locale to discontinuities in meaning [2]. As a result, viewers
usually have doubts about the boundary locations of a meaningful video segment
due to their different affective responses.
This thesis presents an entirely new view to the problem of high level video
segmentation. We developed a novel probabilistic method for affective level video
content analysis and segmentation. Our method had two stages. In the first stage,
a®ective content labels were assigned to video shots by means of a dynamic bayesian
0. Abstract 3
network (DBN). A novel hierarchical-coupled dynamic bayesian network (HCDBN)
topology was proposed for this stage. The topology was based on the pleasure-
arousal-dominance (P-A-D) model of a®ect representation [3]. In principle, this
model can represent a large number of emotions. In the second stage, the visual,
audio and a®ective information of the video was used to compute a statistical feature
vector to represent the content of each shot. Affective level video segmentation was
achieved by applying spectral clustering to the feature vectors.
We evaluated the first stage of our proposal by comparing its emotion detec-
tion ability with all the existing works which are related to the field of a®ective video
content analysis. To evaluate the second stage, we used the time adaptive clustering
(TAC) algorithm as our performance benchmark. The TAC algorithm was the best
high level video segmentation method [2]. However, it is a very computationally
intensive algorithm. To accelerate its computation speed, we developed a modified
TAC (modTAC) algorithm which was designed to be mapped easily onto a field
programmable gate array (FPGA) device. Both the TAC and modTAC algorithms
were used as performance benchmarks for our proposed method.
Since affective video content is a perceptual concept, the segmentation per-
formance and human agreement rates were used as our evaluation criteria. To obtain
our ground truth data and viewer agreement rates, a pilot panel study which was
based on the work of Gross et al. [4] was conducted. Experiment results will show
the feasibility of our proposed method. For the first stage of our proposal, our
experiment results will show that an average improvement of as high as 38% was
achieved over previous works. As for the second stage, an improvement of as high
as 37% was achieved over the TAC algorithm
Adaptive video segmentation
The efficiency of a video indexing technique depends on the efficiency of the video segmentation algorithm which is a fundamental step in video indexing. Video segmentation is a process of splitting up a video sequence into its constituent scenes. This work focuses on the problem of video segmentation. A content-based approach has been used which segments a video based on the information extracted from the video itself. The main emphasis is on using structural information in the video such as edges as they are largely invariant to illumination and motion changes. The edge-based features have been used in conjunction with the intensity-based features in a multi-resolution framework to improve the performance of the segmentation algorithm.;To further improve the performance and to reduce the problem of automated choice of parameters, we introduce adaptation in the video segmentation process. (Abstract shortened by UMI.)
Automatic detection of salient objects and spatial relations in videos for a video database system
Cataloged from PDF version of article.Multimedia databases have gained popularity due to rapidly growing quantities of multimedia data and the need to perform efficient
indexing, retrieval and analysis of this data. One downside of multimedia databases is the necessity to process the data for feature extraction
and labeling prior to storage and querying. Huge amount of data makes it impossible to complete this task manually. We propose a
tool for the automatic detection and tracking of salient objects, and derivation of spatio-temporal relations between them in video. Our
system aims to reduce the work for manual selection and labeling of objects significantly by detecting and tracking the salient objects, and
hence, requiring to enter the label for each object only once within each shot instead of specifying the labels for each object in every frame
they appear. This is also required as a first step in a fully-automatic video database management system in which the labeling should also
be done automatically. The proposed framework covers a scalable architecture for video processing and stages of shot boundary detection,
salient object detection and tracking, and knowledge-base construction for effective spatio-temporal object querying.
(c) 2008 Elsevier B.V. All rights reserved
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