1. A three-dimensional coordinate computing apparatus comprising: an image selecting unit that selects a first selected image from multiple captured images, the multiple captured images being captured by a camera, and selects a second selected image from multiple subsequent images, the multiple subsequent images being captured by the camera after the first selected image has been captured, wherein the selecting the second selected image is performed based on a distance and a number of corresponding feature points, the distance being between a position of capture of the first selected image which is computed based on first marker position information which indicates a position of a marker in the first selected image and a position of capture of each of the multiple subsequent images which is computed based on second marker position information which indicates a position of the marker in each of the multiple subsequent images, and the number of corresponding feature points, each of the corresponding feature points being corresponding one of feature points extracted from the first selected image and one of feature points extracted from each of the multiple subsequent images; and a coordinate computing unit that computes three-dimensional coordinates of the multiple corresponding feature points based on two-dimensional coordinates of each corresponding feature point in each of the first selected image and the second selected image.