1. A robot system, comprising: a robot having a movable section which has multi-jointed arm; an image capture device that is provided on the movable section, and capturing a reference mark, a target object to which the movable section moves and a monochrome region having a difference in brightness between the monochrome region and the reference mark, the image capture device outputting a captured image with a locus image of the monochrome region having a size greater than a size of a locus image of the reference mark; an extractor that extracts the locus image of the reference mark from the captured image; and an image restoration device that restores an image of the reference mark based on a point spread function of the extracted locus image of the reference mark.