Patent ID: 9390330
Filing Date: 2016-07-12
CPC Classification: G06K,G06T

Claim Text:
1. An apparatus for extracting correspondences between aerial images, comprising: one or more processors configured to: extract lines corresponding buildings from two or more aerial images; define directions of the lines as x, y and z axis directions based on a coordinate system of a two-dimensional (2D) image; rotate lines in the x axis direction and lines in the y axis direction so that the lines in the x axis direction are arranged in parallel with a horizontal direction of the 2D image and the lines in the y axis direction are arranged in parallel with a vertical direction of the 2D image, and then extract building top areas from rectangles that are formed by the rotation; extract correspondences between the aerial images by comparing locations of the building top areas extracted from the aerial images; create a direction distribution histogram of the lines, and define directions having three highest peak values in the direction distribution histogram as x, y, and z axis directions, respectively; define one of the highest peak value directions closest to a vertical direction as the z axis direction and two remaining highest peak value directions as the x and y axis directions, respectively; and define an arbitrary one of the two remaining highest peak value directions as the x axis direction and a remaining highest peak value direction as the y axis direction.