1. An image generation device that generates an output image based on an input image captured by a camera attached to an operation target body, comprising: an output image generation unit that associates a value of an input pixel in an input image plane where the input image is positioned with a value of an output pixel in an output image plane where the output image is positioned to generate the output image, wherein a value of an output pixel specified by an integer coordinate point on the output image plane is determined based on values of two input pixels specified by two integer coordinate points selected from four integer coordinate points in the vicinity of a real number coordinate point on the input image plane corresponding to the integer coordinate point on the output image plane.