1. A method for browsing summary images comprising: tracking, by an object extractor, a motion trajectory of an object from an input video; extracting, by the object extractor, the object from the input video and generating a series of object segments; synthesizing, by a summary image generator, the series of object segments with a background image along the motion trajectory of the object; and generating, by the summary image generator, a summary image having a thickness proportional to an appearance duration of the object extracted from the input video.