1. An image display device that displays an image modulated by a light modulation device on an image display surface, comprising: an identification image selector that accepts an operation of selecting a displayed identification image corresponding to one of right, left, upper and lower sides of the image; a moving operator that accepts an operation of moving a node set on an image display surface at a position of a single side of the image, the single side of the image corresponding to the identification image selected with the identification image selector, the position of the single side corresponding to a mid-point of the single side; a processor executing a program configured to: display the displayed identification image; and correct a shape of the image by moving, based on the operation accepted with the moving operator, the node of the image displayed on the image display surface composed of at least two non-parallel surfaces; and a mode selector that accepts an operation of selecting a horizontal corner mode in which the shape of the image is corrected when the at least two non-parallel surfaces of the image display surface form a horizontal corner at the mid-point of the single side, or a vertical corner mode in which the shape of the image is corrected when the at least two non-parallel surfaces of the image display surface form a vertical corner at the mid-point of the single side, wherein the program is further configured to: display, when the horizontal corner mode is selected, a first identification image corresponding to an upper left corner of the image, a second identification image corresponding to a lower left corner of the image, a third identification image corresponding to an upper right corner of the image, a fourth identification image corresponding to a lower right corner of the image, a fifth identification image corresponding to an upper side of the image, and a sixth identification image corresponding to a lower side of the image without displaying a seventh identification image corresponding to a left side of the image and an eighth identification image corresponding to a right side of the image; and display, when the vertical corner mode is selected, the first identification image, the second identification image, the third identification image, the fourth identification image, the seventh identification image, and the eighth identification image without displaying the fifth identification image and the sixth identification image.