Detection of representative frames of a shot using multivariate Wald-Wolfowitz test

For efficient indexing, browsing and retrieval of video data and also for video summarization, extraction of representative frames is essential. Once a video stream is segmented into shots, the representative frames or key-frames for the shot are selected. Automatic selection of suitable representatives for a wide variety of shots is still a challenge as the number of such frames in a shot may also vary depending on the variation in the content. In this work, we propose a novel scheme that relies on Wald-Wolfowitz runs test based hypothesis testing to detect the subshots within a shot and then for each subshot, the frame rendering the highest fidelity is extracted as the key-frame. Experimental result shows that the scheme works satisfactorily for a wide variety of shots.