Patent ID: 11913912
Assignee: INDUSTRY-UNIVERSITY COOPERATION FOUNDATION HANYANG UNIVERSITY
Field: Measurement (Instruments)
Classification: CPC G | IPC G

Claim 11:
12. A hole expansion ratio testing method comprising:
holding a plate member having a hole;
expanding the hole by inserting the punching unit into the interior of the hole;
acquiring an image of the hole while the hole is expanded;
extracting an interest area corresponding to the hole from the acquired image;
linearizing the interest area; and
providing information on a crack as a blob changes due to the linearization,
wherein the extracting of the interest area comprises:
when the plate member has not been plated,
selecting a specific pixel from the binarized image, and detecting blobs by grouping adjacent pixels having the same gray scale as the specific pixel; and
removing the largest blob from the detected blobs, and providing, among the blobs left after the removal, a blob that is most distant from the center of the image as the interest area, and
when the plate member has been plated,
selecting a specific pixel from the binarized image, and detecting blobs by grouping adjacent pixels having the same gray scale as the specific pixel; and
providing a blob that is most distance from the center of the image as the interest area.