A method of characterizing a video includes the steps of extracting frame images from an input video, calculating a time length between each of the frame images and a next one of the frame images, assigning index information determined by the calculated time length to each of the frame images, stringing together the index information assigned to the frame images, and characterizing the input video by the strung-together index information. The index information is a character code, and the strung-together index information is a character code string. The frame images include head frame images located at scene changes of the input video. The input video is being broadcasted or is included in a data base.