A Lightweight Video Summarization Method Considering the Subjective Transition Degree for Online Educational Screen Content Videos.

With the popularization of online education, the number of educational videos is increasing, and some shoddy and dangerous videos also become potential threat to the mental health of students and the public security. Therefore, efficient video summarization technology is critical for the analysis, retrieval, and management of online educational videos. Online education videos usually belong to the screen content videos (SCV), and is typical real-time communication system, which urgently needs lightweight technologies with fast speed and low hardware requirements. Therefore, the traditional video summarization method for nature videos or with high complexity cannot be effectively applied for the online educational videos. SCV generated by screen recording the play of the Power Point (PPT-SCV) has also been widely applied in education field. Therefore, taking the PPT-SCV as an example, this paper proposed a lightweight video summarization method for the educational videos. First, the average standard deviation among frames and the variance of frame difference in a video clip which can effectively reflect the content characteristics of PPT-SCV were used to obtain the category of transitions and the key frames. Then, the subjective transition degree in video is used for marking the knowledge importance of each key frames, and a lightweight video summarization method was finally proposed. Experimental results demonstrated that the proposed method can efficiently locate the key frames which is in line with subjective perception.