ビデオ教材の画像抽出法の検討 : タイムサンプリングによるショット抽出の理論  [in Japanese] Time Sampling of Pictures from Video Programs  [in Japanese]

In order to analyze, compare and evaluate a number of educational video programs, it is necessary to have a sampling technique which provides us with samples of representative pictures summarizing the visual information of the programs. Fujita, K. (1989) reported that most shot length distributions of video programs can be described by a compound exponential distribution. On the basis of his previous study, we theoretically estimated the precentage of shots sampled by time sampling with various time intervals. The agreement between the estimated and the oberved values was exceedingly good for all of the 53 educational video programs examined. It was found that for most videos more than 95 % of the shots were sampled by the time samling method with 5-10 second time intervals. A variety of applications of this method to educational and technical use are discussed and demonstrated.