I.: Visual Signatures in Video Visualization

Abstract — Video visualization is a computation process that extracts meaningful information from original video data sets and conveys the extracted information to users in appropriate visual representations. This paper presents a broad treatment of the subject, following a typical research pipeline involving concept formulation, system development, a path-finding user study and a field trial with real application data. In particular, we have conducted a fundamental study on the visualization of motion events in videos. We have, for the first time, deployed flow visualization techniques in video visualization. We have visual representations of videos. We have conducted a user study to examine whether users are able to learn to recognize visual signatures of motions, and to assist in the evaluation of different visualization techniques. We have applied our understanding and the developed techniques to a set of application video clips. Our study has demonstrated that video visualization is both technically feasible and cost-effective. It provided the first set of evidence confirming that ordinary users can accustom to the visual features depicted in video visualizations, and can learn to recognize visual signatures of a variety of motion events. Index Terms — video visualization, volume visualization, flow visualization, human factors, user study, visual signatures, video processing, optical flow, GPU-rendering. I