US 11,657,536 B2
Target, method, and system for camera calibration
Andreas Wendel, Mountain View, CA (US); Volker Grabe, Redwood City, CA (US); Jeremy Dittmer, Mountain View, CA (US); and Zachary Morriss, San Francisco, CA (US)
Assigned to Waymo LLC, Mountain View, CA (US)
Filed by Waymo LLC, Mountain View, CA (US)
Filed on Jan. 14, 2021, as Appl. No. 17/149,621.
Application 17/149,621 is a continuation of application No. 16/547,427, filed on Aug. 21, 2019, granted, now 10,930,014.
Application 16/547,427 is a continuation of application No. 15/720,979, filed on Sep. 29, 2017, granted, now 10,432,912, issued on Oct. 1, 2019.
Prior Publication US 2021/0134012 A1, May 6, 2021
Int. Cl. G06T 7/80 (2017.01); H04N 13/246 (2018.01); H04N 13/282 (2018.01); G01B 11/25 (2006.01); G06T 7/60 (2017.01); G06V 20/56 (2022.01)
CPC G06T 7/80 (2017.01) [G01B 11/2504 (2013.01); G06T 7/60 (2013.01); H04N 13/246 (2018.05); H04N 13/282 (2018.05); G06T 2207/30204 (2013.01); G06V 20/56 (2022.01)] 17 Claims
OG exemplary drawing
 
1. A target used for calibration, comprising:
a panel having a first plurality of fiducial markers arranged on the panel in a first pattern and a second plurality of fiducial markers arranged on the panel in a second pattern,
wherein the first pattern is a scaled version of the second pattern, such that a calibration image captured of the target simulates multiple images of a single pattern captured at multiple calibration perspectives, and
wherein fiducial markers of the first plurality of fiducial markers have a different shape than fiducial markers of the second plurality of fiducial markers,
wherein at least one fiducial marker of at least a portion of the first and second pluralities of fiducial markers comprises a plurality of distinct regions, and
wherein the plurality of distinct regions comprises at least two of: a first region having a crosshair that indicates a center of the fiducial marker, a second region having an angular barcode that uniquely identifies the fiducial marker within a calibration image taken of the fiducial marker, a third region that identifies a boundary of the fiducial marker, or a fourth region having a human-readable label that uniquely identifies the fiducial marker within the calibration image taken of the fiducial marker.