Comparison image generating device, method, and program

Abstract

To provide a comparison image generation apparatus which can generate a comparison image suitable for use in estimating an attitude of a camera based on an image.SOLUTION: A comparison image retrieval apparatus is configured to: estimate, as a camera position / attitude for first estimation, a camera position / attitude in a three-dimensional map of a query image by performing image matching between the query image and a group of comparison images for the first estimation selected from images which have been rendered in advance in one or more camera positions / attitudes from the three-dimensional map; repeat, until convergence is determined, estimating a camera position / attitude for the current estimation, by performing image matching between the query image and a group of comparison image for the current estimation obtained by rendering, for the current estimation, in one or more camera positions / attitudes from the three-dimensional map, on the basis of a camera position / attitude estimated for the previous estimation by repeating estimations following the first estimation, for the current estimation of the second and subsequent estimations; and output the group of comparison images used at the estimation in which the convergence is determined.SELECTED DRAWING: Figure 1