Patent Document ID: 9824303
Application ID: 14529875
Patent Status: 1

Claim One:
1. An image matching method for matching at least two images, the image matching method comprising: extracting a plurality of feature points from a reference image; selecting a first feature point from the feature points extracted from the reference image, and selecting a first reference search area comprising the first feature point; setting a first matching candidate search area corresponding to the first reference search area from a target image, and extracting a plurality of feature points from the first matching candidate search area; selecting a second feature point closest to the first feature point in the first reference search area, and selecting a first straight line connecting the first and second feature points; generating a plurality of line segments, each connecting two feature points among the plurality of feature points extracted from the first matching candidate search area, wherein if a number of the plurality of feature points extracted from the first matching candidate search area is N, a number of the line segments generated from the plurality of feature points extracted from the first matching candidate search area is N×(N−1); comparing the first straight line with each of the N×(N−1) number of the line segments generated from the plurality of feature points extracted from the first matching candidate search area; determining, based on a result of the comparing the first straight line with each of the N×(N−1) number of the line segments, a first matching straight line of which a length and an angle, with respect to a horizontal line of the target image, match a length and an angle, with respect to a horizontal line of the reference image, of the first straight line, from the N×(N−1) number of the line segments generated from the plurality of feature points extracted from the first matching candidate search area; selecting a second reference search area based on the second feature point forming the first straight line; setting a second matching candidate search area corresponding to the second reference search area from the target image, and extracting a plurality of feature points from the second matching candidate search area; selecting a third feature point closest to the second feature point in the second reference search area, and selecting a second straight line connecting the second and third feature points; searching the second matching candidate search area for a second matching straight line corresponding to the second straight line; and matching the reference image to the target image based on the first straight line, the first matching straight line, the second straight line, and the second matching straight line, and outputting a result of the matching.