US 12,474,232 B2
Device and method for calibrating a light projector
Michael Hödlmoser, Schörfling (AT); Florian Seitner, Vienna (AT); Robert Fischer, Vienna (AT); and Matej Nezveda, Vienna (AT)
Assigned to emotion3D GmbH, Vienna (AT)
Appl. No. 17/913,571
Filed by emotion3D GmbH, Vienna (AT)
PCT Filed Mar. 22, 2021, PCT No. PCT/EP2021/057206
§ 371(c)(1), (2) Date Sep. 22, 2022,
PCT Pub. No. WO2021/191121, PCT Pub. Date Sep. 30, 2021.
Claims priority of application No. A 50244/2020 (AT), filed on Mar. 24, 2020.
Prior Publication US 2023/0109225 A1, Apr. 6, 2023
Int. Cl. G01M 11/06 (2006.01); G06T 7/73 (2017.01)
CPC G01M 11/065 (2013.01) [G06T 7/74 (2017.01); G06T 2207/10028 (2013.01); G06T 2207/30204 (2013.01); G06T 2207/30244 (2013.01); G06T 2207/30252 (2013.01)] 14 Claims
OG exemplary drawing
 
1. A device for calibrating a light projector with adaptable light elements arranged in an image plane, comprising
a. a control unit connected to the light projector and the camera, and
b. a storage unit connected to the control unit, wherein
c. the light projector is configured to project in temporal sequence at least two identical test images with at least two comparison structures in the form of visually concise structures from the image plane to a projection surface during a spatial change of the light projector relative to the projection surface and while the relative positioning between the light projector and camera remains constant,
d. a depth camera configured to
i. capture at least two camera images of a capturing surface synchronised in time with the light projector, the capturing surface substantially comprising the projection surface,
ii. detect the three-dimensional position data of the identical comparison structures in the camera images,
wherein the control unit is configured to
i. determine the position and orientation of the light projector (1) from the three-dimensional position data of the identical comparison structures by reconstructing two light beams that run through one and the same comparison structure at different points in time, and determining the intersection of the two light beams, and
ii. calculate the translational displacement and rotation between camera and projector relative to an initial position by comparing the determined coordinates of the light projector with a previously stored initial position;
wherein the visually concise structures are selected from a group consisting of reticles and evenly spaced circles.