An image generation device generates an output image based on an input image captured by a camera attached to a shovel. Further, the image generation device includes an output image generation unit that associates a value of an input pixel in the input image with a value of an output pixel in the output image to generate the output image. A value of an output pixel specified by an integer coordinate point on an 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 an input image plane corresponding to the integer coordinate point on the output image plane.