Generating a Time Shrunk Lecture Video by Event Detection
Generating a Time Shrunk Lecture Video by Event Detection
复制标题
通过事件检测生成时间缩短的讲座视频
DOI：
10.1109/icme.2006.262527
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发表时间：
2006
期刊：
影响因子：
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通讯作者：
H. Fujiyoshi
中科院分区：
文献类型：
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作者：
Takao Yokoi;H. Fujiyoshi
通过互联网播放讲座视频对电子学习很重要。我们基于广播摄像师的拍摄技术，开发了一个利用虚拟摄像生成讲座视频的系统。然而，观看完整长度的视频对学生来说需要时间。在本文中，我们提出了一种使用事件检测生成时间压缩讲座视频的方法。我们检测到两种事件：演讲时段和黑板书写时段。通过LPC倒谱的语音活动检测来检测语音周期，并利用马氏距离对语音和非语音进行分类。为了检测黑板上的书写时间，我们使用图形切割技术来分割一个精确的兴趣区域，例如讲师。我们的方法通过删除无内容的时间段，即没有演讲和写作事件的时间段，以及快进的写作时间段，可以自动生成时间缩减的讲座视频。由此生成的视频在时间上比原始视频短20%~30%。这与人工编辑的结果几乎相同
Streaming a lecture video via the Internet is important for e-learning. We have developed a system that generates a lecture video using virtual camerawork based on shooting techniques of broadcast cameramen. However, viewing a full-length video takes time for students. In this paper, we propose a method for generating a time shrunk lecture video using event detection. We detect two kinds of events: a speech period and a chalkboard writing period. A speech period is detected by voice activity detection with LPC cepstrum and classified into speech or non-speech using Mahalanobis distance. To detect chalkboard writing periods, we use a graph cuts technique to segment a precise region of interests such as an instructor. By deleting content-free periods, i.e, period without the events of speech and writing, and fast-forwarding writing periods, our method can generate a time shrunk lecture video automatically. The resulting generated video is about 20%~30% shorter than the original video in time. This is almost the same as the results of manual editing by a human operator