1. An image generation system which generates a stereoscopic image, the image generation system comprising: a first image generation section which generates a first image of an object for a left eye as seen from a viewpoint position for the left eye within an object space, and also generates a first image of the object for a right eye as seen from a viewpoint position for the right eye within the object space; a second image generation section which generates a second image for the left eye by subjecting the first image for the left eye to correction processing for removing perspective of an image at a base surface in the first image for the left eye, and also generates a second image for the right eye by subjecting the first image for the right eye to correction processing for removing perspective of an image at the base surface in the first image for the right eye; and a stereoscopic image generation section which generates a stereoscopic image based on the second image for the left eye and the second image for the right eye.