1. An autostereoscopic image display device in which an image of each viewpoint can be observed in each one of a plurality of observation areas, wherein one or both of a pair of images having relationship of a reverse view near an end portion of the observation area are displayed by using first image data and added image data acquired by weighting values of the first image data and second image data based on relationship of parallax between the second image data different from the first image data and the first image data and adding the weighted values.