US 12,333,781 B2
Method for searching for hole pattern in image, pattern inspection method, pattern inspection apparatus, and apparatus for searching hole pattern in image
Shinji Sugihara, Ota-ku (JP)
Assigned to NuFlare Technology, Inc., Yokohama (JP)
Filed by NuFlare Technology, Inc., Yokohama (JP)
Filed on Aug. 4, 2022, as Appl. No. 17/817,517.
Application 17/817,517 is a continuation of application No. PCT/JP2021/003882, filed on Feb. 3, 2021.
Claims priority of application No. 2020-041385 (JP), filed on Mar. 10, 2020.
Prior Publication US 2022/0375195 A1, Nov. 24, 2022
Int. Cl. G06V 10/75 (2022.01); G06T 7/00 (2017.01)
CPC G06V 10/751 (2022.01) [G06T 7/0004 (2013.01)] 14 Claims
OG exemplary drawing
 
1. A method for searching a hole pattern in an image comprising:
extracting, from an image where a hole pattern is formed, a plurality of outline position candidates serving as candidates for a plurality of positions where an outline of the hole pattern passes;
generating, with respect to each pixel in a region including the plurality of outline position candidates, for each direction of a plurality of directions, a distance map which defines a distance from each of the plurality of outline position candidates to each of pixels arrayed in a target direction of the plurality of directions;
extracting a candidate for a center pixel of the hole pattern by using the distance map generated for the each direction; and
searching, in the plurality of outline position candidates, a group of outline position candidates which satisfies a predetermined condition in a case of using the candidate for the center pixel as a starting point, as a plurality of outline positions where the outline of the hole pattern passes.