一种基于模型的扫换检测方法

视频自动分割是实现视频数据库检索必不可少的一个过程,其基础是镜头边界检测.当前已有的算法能够较准确地检测出镜头突变,但对于镜头的渐变则常常会漏检,这是由于镜头渐变时帧间差没有一个明显的峰值,因而其检测比突变检测要困难得多.扫换是一种常用的视频空间编辑手段,用于实现多种镜头变化.通过分析各种类型的扫换,提出了一种新的基于视频空间编辑模型的扫换检测算法,其性能优于Alattar提出的基于统计特征的算法.对用AdobePremiere5.1生成的各种扫换视频进行检测.实验结果表明,这种扫换检测算法能够较好地适应     

AVCD-FRA: A novel solution to automatic video cut detection using fuzzy-rule-based approach

Video shot boundary detection (SBD) is a fundamental step in automatic video content analysis toward video indexing, summarization and retrieval. Despite the beneficial previous works in the literature, reliable detection of video shots is still a challenging issue with many unsolved problems. In this paper, we focus on the problem of hard cut detection and propose an automatic algorithm in order to accurately determine abrupt transitions from video. We suggest a fuzzy rule-based scene cut identification approach in which a set of fuzzy rules are evaluated to detect cuts. The main advantage of the proposed method is that, we incorporate spatial and temporal features to describe video frames, and model cut situations according to temporal dependency of video frames as a set of fuzzy rules. Also, while existing cut detection algorithms are mainly threshold dependent; our method identifies cut transitions using a fuzzy logic which is more flexible. The proposed algorithm is evaluated on a variety of video sequences from different genres. Experimental results, in comparison with the most standard cut detection algorithms confirm our method is more robust to object and camera movements as well as illumination changes.     

基于DC系数和运动矢量的快速场景分割算法

场景分割技术是动态视频分析和基于内容的视频检索的基础，以检测出来的场景作为基本单元，可以进一步对视频内容进行分析和建立索引．本文旨在提出一种基于MPEG压缩视频流的场景分割算法，利用MPEG数据流中已有的DCT DC系数和运动矢量，来检测场景的变换，从而实现场景分割，针对实际视频流中场景突变和渐变两类变换．本文提出两种方法分别处理不同情况，对于突变检测，该算法可以定位到帧，由于该算法进行最小程度的解码，降低了计算复杂度，因而大大提高了检测速度．     

基于全图象的视频分段方法研究

视频分段技术是未来信息高速公路上基于内容视频检索服务的基本和关键技术。介绍了目前几类视频分段方法的基本思想，并主要讨论了基于全图象的视频突变和渐变分段方法。     

Automatic detection and indexing of video-event shots for surveillance applications

Increased communication capabilities and automatic scene understanding allow human operators to simultaneously monitor multiple environments. Due to the amount of data to be processed in new surveillance systems, the human operator must be helped by automatic processing tools in the work of inspecting video sequences. In this paper, a novel approach allowing layered content-based retrieval of video-event shots referring to potentially interesting situations is presented. Interpretation of events is used for defining new video-event shot detection and indexing criteria. Interesting events refer to potentially dangerous situations: abandoned objects and predefined human events are considered in this paper. Video-event shot detection and indexing capabilities are used for online and offline content-based retrieval of scenes to be detected.     

视频检索中镜头分割方法综述

视频序列的镜头分割亦称镜头变化检测是视频检索中的关键技术之一。镜头变化是指视频序列中场景内容的变化。该文介绍了目前镜头分割的常用方法,包括灰度分割法、边缘分割法、彩色直方图分割法、MPEG视频的分割方法、块匹配镜头分割方法、统计判决镜头分割方法、基于聚类的镜头分割方法、镜头渐变的检测等,指出了研究场景内容的表征方法、特征提取方法、特征的检测尺度以及稳健可靠的实用镜头分割方法是目前主要的研究方向。     

Scene Detection in Videos Using Shot Clustering and Sequence Alignment

Video indexing requires the efficient segmentation of video into scenes. The video is first segmented into shots and a set of key-frames is extracted for each shot. Typical scene detection algorithms incorporate time distance in a shot similarity metric. In the method we propose, to overcome the difficulty of having prior knowledge of the scene duration, the shots are clustered into groups based only on their visual similarity and a label is assigned to each shot according to the group that it belongs to. Then, a sequence alignment algorithm is applied to detect when the pattern of shot labels changes, providing the final scene segmentation result. In this way shot similarity is computed based only on visual features, while ordering of shots is taken into account during sequence alignment. To cluster the shots into groups we propose an improved spectral clustering method that both estimates the number of clusters and employs the fast global k-means algorithm in the clustering stage after the eigenvector computation of the similarity matrix. The same spectral clustering method is applied to extract the key-frames of each shot and numerical experiments indicate that the content of each shot is efficiently summarized using the method we propose herein. Experiments on TV-series and movies also indicate that the proposed scene detection method accurately detects most of the scene boundaries while preserving a good tradeoff between recall and precision.     

一种分层的和多分辨的镜头边界检测方法

提出了一种分层的和多分辨的镜头边界检测方法。该方法对各种不同的镜头间过渡类型给出了用不同方法进行联合检测的方案,该方案主要分为突变镜头检测（即视频切分）,淡化过渡检测、溶解过渡检测及划变过渡检测4个部分。检测方案并不是简单地将各种方法拼接在一起,而是通过小波变换的多分辨分析将它们有机地结合起来,相互关联,达到有效检测结果。首先用FCM聚类算法进行视频切分,然后根据聚类结果分别在整数小波分解后的高频部分用Gaussian加权Hausdorff距离结合边界改变率算法检测淡化过渡;对分解后的低频部分用所提出的SCD算法（Similarity of color distribution based method）检测溶解过渡,并通过自适应调节权系数（系数盲调节）使检测相异度函数更能适用于多种视频片段。最后根据切分以及前面两种过渡检测的结果,利用三维小波分解后高频成分中的运动部分所定义的运动矢量来检测划变过渡。用实际视频数据所做的仿真实验结果表明,该方法不但能同时检测突变过渡和渐变过渡,而且能准确地判断渐变过渡的类型及其位置。此外,还能有效地抑制闪光、运动等的影响,从而提高了检测精度。     

一种有效的镜头探测方法

镜头是视频分析和检索的基本单元,根据两个相续镜头处视频内容的变化情况,可以把镜头边界分为突变和渐变两种。镜头探测的方法很多,但大多都是针对某一类镜头准确性很高。文中,介绍了一种有效的镜头探测方法,此方法综合利用双直方图比较法和MPEG视频流中B帧宏块的信息来探测镜头边界,对不同类型的镜头,都取得了很高的准确性。通过对十几段不同类型MPEG_I视频节目进行试验,效果相当理想。     

Shot Change Detection Using Scene-Based Constraint

A key step for managing a large video database is to partition the video sequences into shots. Past approaches to this problem tend to confuse gradual shot changes with changes caused by smooth camera motions. This is in part due to the fact that camera motion has not been dealt with in a more fundamental way. We propose an approach that is based on a physical constraint used in optical flow analysis, namely, the total brightness of a scene point across two frames should remain constant if the change across two frames is a result of smooth camera motion. Since the brightness constraint would be violated across a shot change, the detection can be based on detecting the violation of this constraint. It is robust because it uses only the qualitative aspect of the brightness constraint—detecting a scene change rather than estimating the scene itself. Moreover, by tapping on the significant know-how in using this constraint, the algorithm's robustness is further enhanced. Experimental results are presented to demonstrate the performance of various algorithms. It was shown that our algorithm is less likely to interpret gradual camera motions as shot changes, resulting in a significantly better precision performance than most other algorithms.     

Real time repeated video sequence identification

In this paper, we present a real time system for detecting repeated video clips from a live video source such as news broadcasts. Our system utilizes customized temporal video segmentation techniques to automatically partition the digital video signal into semantically sensible shots and scenes. As each frame of the video source is processed, we extract auxiliary information to facilitate repeated sequence detection. When the video transition marking the end of the shot/scene is detected, we are able to rapidly locate all previous occurrences of the video clip. Our objective is to use repeated sequence information in our multimedia content analysis application to deduce semantic relationships among shots/scenes in the input video. Our real time video processing techniques are independent of source and domain and can be applied to other applications such as commercial detection and improved video compression.     

Efficient MPEG compressed video analysis using macroblock typeinformation

Efficient indexing methods are required to handle the rapidly increasing amount of visual information within video databases. Video analysis that partitions the video into clips or extracts interesting frames is an important preprocessing step for video indexing. We develop a novel method for video analysis using the macroblock (MB) type information of MPEG compressed video bitstreams. This method exploits the comparison operations performed in the motion estimation procedure, which results in specific characteristics of the MB type information when scene changes occur or some special effects are applied. Only a simple analysis on MB types of frames is needed to achieve very fast scene change, gradual transition, flashlight, and caption detection. The advantages of this novel approach are its direct extraction from the MPEG bitstreams after VLC decoding, very low complexity analysis, frame-based detection accuracy and high sensitivity     

视频层次结构挖掘

视频处理的关键是视频信息的结构化,视频基本结构是由帧、镜头、场景和视频节目构成的层次结构。视频层次结构挖掘的一个简单框架是对视频进行镜头分割、抽取镜头特征和视频场景构造。论文在镜头分割的基础上提出了基于多特征的镜头聚类分析和基于镜头的场景边界检测两种视频场景构造方法,从而实现视频层次结构挖掘。实验表明,基于镜头的场景边界检测性能优于基于多特征的镜头聚类分析。     

视频镜头时域分割方法的研究

视频时域分割指将视频序列分成若干镜头，是视频内容分析以及基于内容的视频浏览和检索的第一步．该文首先对视频结构以及视频镜头种类进行了简要的描述，然后对为计算不连续性而采用的提取特征和建立测量准则的常用方法进行概述．其后，文章介绍了检测镜头切变和渐变的算法及其优缺点．在压缩域上检测镜头变换边界的问题也在文中予以分析．在结论与展望中，提出了一些这一领域的难点和对今后工作的展望．     

压缩域中叠化镜头的快速检测算法

随着网络和多媒体技术的不断发展，基于内容的多媒体信息检索技术变得越来越重要．同成熟的文本检索技术相比，视频检索还处在研究和探索阶段．视频检索的一个有效方法是将无结构的视频节目进行镜头分割，根据每个镜头的关键帧对视频建立索引．因此，镜头分割是基于内容的视频检索的基本步骤，在各种类型的镜头检测算法中，叠化镜头是很难检测的．根据叠化(dissolve)镜头内部预测帧预测误差能量和运动矢量分布特点，提出一种在压缩域中分割叠化镜头的新算法．与公开发表的同类算法相比，它具有以下优点：工作在压缩域上、速度快、鲁棒性好、精度更高．     

Shot Change Detection via Local Keypoint Matching

Shot change detection is an essential step in video content analysis. However, automatic shot change detection often suffers from high false detection rates due to camera or object movements. To solve this problem, we propose an approach based on local keypoint matching of video frames. This approach aims to detect both abrupt and gradual transitions between shots without modeling different kinds of transitions. Our experiment results show that the proposed algorithm is effective for most kinds of shot changes.      

基于内容的视频检索的突变场景变换探测算法

讲述了目前正在使用的突变场景变换探测算法，并列举了一种新的基于压缩视频的突变场景变换探测算法，实验结果显示，这个算法不受视频种类的限制，能取得满意的结果。     

A fuzzy logic approach for detection of video shot boundaries

Video temporal segmentation is normally the first and important step for content-based video applications. Many features including the pixel difference, colour histogram, motion, and edge information etc. have been widely used and reported in the literature to detect shot cuts inside videos. Although existing research on shot cut detection is active and extensive, it still remains a challenge to achieve accurate detection of all types of shot boundaries with one single algorithm. In this paper, we propose a fuzzy logic approach to integrate hybrid features for detecting shot boundaries inside general videos. The fuzzy logic approach contains two processing modes, where one is dedicated to detection of abrupt shot cuts including those short dissolved shots, and the other for detection of gradual shot cuts. These two modes are unified by a mode-selector to decide which mode the scheme should work on in order to achieve the best possible detection performances. By using the publicly available test data set from Carleton University, extensive experiments were carried out and the test results illustrate that the proposed algorithm outperforms the representative existing algorithms in terms of the precision and recall rates.     

Video segmentation using a histogram-based fuzzy c-means clustering algorithm

The purpose of video segmentation is to segment video sequence into shots where each shot represents a sequence of frames having the same contents, and then select key frames from each shot for indexing. Existing video segmentation methods can be classified into two groups: the shot change detection (SCD) approach for which thresholds have to be pre-assigned, and the clustering approach for which a prior knowledge of the number of clusters is required. In this paper, we propose a video segmentation method using a histogram-based fuzzy c-means (HBFCM) clustering algorithm. This algorithm is a hybrid of the two approaches aforementioned, and is designed to overcome the drawbacks of both approaches. The HBFCM clustering algorithm is composed of three phases: the feature extraction phase, the clustering phase, and the key-frame selection phase. In the first phase, differences between color histogram are extracted as features. In the second phase, the fuzzy c-means (FCM) is used to group features into three clusters: the shot change (SC) cluster, the suspected shot change (SSC) cluster, and the no shot change (NSC) cluster. In the last phase, shot change frames are identified from the SC and the SSC, and then used to segment video sequences into shots. Finally, key frames are selected from each shot. Simulation results indicate that the HBFCM clustering algorithm is robust and applicable to various types of video sequences.     

Structuring low-quality videotaped lectures for cross-reference browsing by video text analysis

This paper presents an unified approach in analyzing and structuring the content of videotaped lectures for distance learning applications. By structuring lecture videos, we can support topic indexing and semantic querying of multimedia documents captured in the traditional classrooms. Our goal in this paper is to automatically construct the cross references of lecture videos and textual documents so as to facilitate the synchronized browsing and presentation of multimedia information. The major issues involved in our approach are topical event detection, video text analysis and the matching of slide shots and external documents. In topical event detection, a novel transition detector is proposed to rapidly locate the slide shot boundaries by computing the changes of text and background regions in videos. For each detected topical event, multiple keyframes are extracted for video text detection, super-resolution reconstruction, binarization and recognition. A new approach for the reconstruction of high-resolution textboxes based on linear interpolation and multi-frame integration is also proposed for the effective binarization and recognition. The recognized characters are utilized to match the video slide shots and external documents based on our proposed title and content similarity measures.