US 11,920,913 B2
Conversion parameter calculation method, displacement amount calculation method, conversion parameter calculation device, and displacement amount calculation device
Akihiro Noda, Osaka (JP); Taro Imagawa, Osaka (JP); Yuki Maruyama, Osaka (JP); and Hiroya Kusaka, Hyogo (JP)
Assigned to PANASONIC INTELLECTUAL PROPERTY MANAGEMENT CO., LTD., Osaka (JP)
Filed by Panasonic Intellectual Property Management Co., Ltd., Osaka (JP)
Filed on Mar. 21, 2022, as Appl. No. 17/699,418.
Application 17/699,418 is a continuation of application No. PCT/JP2020/025232, filed on Jun. 26, 2020.
Claims priority of application No. 2019-190126 (JP), filed on Oct. 17, 2019.
Prior Publication US 2022/0205776 A1, Jun. 30, 2022
Int. Cl. G01B 11/02 (2006.01); G01B 11/03 (2006.01); G01B 11/25 (2006.01); G06K 7/14 (2006.01)
CPC G01B 11/022 (2013.01) [G01B 11/026 (2013.01); G01B 11/03 (2013.01); G01B 11/2518 (2013.01); G06K 7/1417 (2013.01)] 8 Claims
OG exemplary drawing
 
1. A conversion parameter calculation method for calculating a conversion parameter for measuring, using images, an actual displacement amount that is an actual value of a displacement indicating movement of an object, the conversion parameter calculation method comprising:
obtaining, from an image capturing device, first image data obtained by the image capturing device capturing an image of the object, the object having attached thereto a marker with which specific coordinates are detectable;
obtaining displacement direction information indicating a direction of a displacement of the object, the direction crossing an image capturing surface of the image capturing device;
detecting the specific coordinates, based on the marker included in the first image data;
estimating a position of the image capturing device, based on a result of detecting the specific coordinates and a parameter of the image capturing device;
calculating distance data indicating a distance from the image capturing device to the object, based on the specific coordinates and the position of the image capturing device; and
calculating the conversion parameter, using the distance data and the displacement direction information, the conversion parameter being a parameter for converting, into the actual displacement amount, a pixel displacement amount at a measurement point on the object between at least two second image data items captured by the image capturing device at different times.