US 12,439,024 B2
Provision of real world and image sensor correspondence points for use in calibration of an imaging system for three dimensional imaging based on light triangulation
Daniel Rydström, Linköping (SE)
Assigned to SICK IVP AB, Linköping (SE)
Filed by SICK IVP AB, Linköping (SE)
Filed on Oct. 20, 2023, as Appl. No. 18/490,837.
Claims priority of application No. 22211198 (EP), filed on Dec. 2, 2022.
Prior Publication US 2024/0187565 A1, Jun. 6, 2024
Int. Cl. G06T 7/80 (2017.01); H04N 17/04 (2006.01)
CPC H04N 17/04 (2013.01) [G06T 7/80 (2017.01)] 11 Claims
OG exemplary drawing
 
1. A method performed by one or more devices (405; 430; 434; 900), for provision of a pair of real world and image sensor correspondence points for use in calibration of an imaging system (405) for three dimensional imaging based on light triangulation, said imaging system comprising a camera (430; 530) with image sensor (431) and a light source (410; 510) for providing a light plane (411; 511), said light triangulation involving imaging by said camera of reflected light resulting from said light plane (411; 511) intersecting with and thereby causing reflections from a surface, said correspondence points being a real world point (514-1; 529-1), located in said light plane (411; 511), and an image sensor point (544-1; 554-1) that corresponds to where said real world point (514-1; 529-1) is imaged on the image sensor (431) by the imaging system (405), wherein the method is characterized by:
providing (801) said real world point (514-1; 529-1) as a first virtual intersection between a first real world line (512a; 527a) and a second real world line (512b; 527b),
wherein said first real world line (512a; 527a) corresponds to a first real intersection between a first real surface (521a; 526a) and the light plane (511) and wherein reflected light from said first real intersection is captured by the imaging system (405) in a first image (540a; 550a), and
wherein said second real world line (512b; 527b) corresponds to a second real intersection between a second real surface (521b; 527b) and the light plane (411; 511) and wherein reflected light from said second real intersection is captured by the imaging system (405) in another, second, image (540b; 550b); and
providing (802) said image sensor point (544-1; 554-1) as a second virtual intersection between a first image line (542a; 552a) corresponding to positions of intensity peaks of said captured light in the first image (540a; 550a) and a second image line (542b; 552b) corresponding to positions of intensity peaks of said captured light in the second image (540b; 550b).