Lecture Video Automatic Summarization System Based on DBNet and Kalman Filtering

Video summarization for educational scenarios aims to extract and locate the most meaningful frames from the original video based on the main contents of the lecture video. Aiming at the defect of existing computer vision-based lecture video summarization methods that tend to target specific scenes, a summarization method based on content detection and tracking is proposed. Firstly, DBNet is introduced to detect the contents such as text and mathematical formulas in the static frames of these videos, which is combined with the convolutional block attention module (CBAM) to improve the detection precision. Then, frame-by-frame data association of content instances is performed using Kalman filtering, the Hungarian algorithm, and appearance feature vectors to build a tracker. Finally, video segmentation and key frame location extraction are performed according to the content instance lifelines and content deletion events constructed by the tracker, and the extracted key frame groups are used as the final video summary result. Experimenting on a variety of scenarios of lecture video, the average precision of content detection is 89.1%; the average recall of summary results is 92.1%.