1. An image generation system comprising: an image information acquisition section that acquires image information from an image sensor; a skeleton information acquisition section that acquires skeleton information based on the image information from the image sensor, the skeleton information specifying a motion of an operator; a reliability information acquisition section that acquires reliability information that indicates reliability of the skeleton information; and an image generation section that generates an image displayed on a display section, the image generation section generating an image corresponding to the acquired reliability information as the image displayed on the display section, and the reliability information acquisition section acquiring the reliability information in which reliability of information about each bone included in the skeleton information decreases when the operator is positioned at a distance equal to or greater than a given distance from the image sensor.