machinevisiontoolbox.Image.fiducial

Image.fiducial(dict='4x4_1000', K=None, side=None)

Find fiducial markers in image

Parameters:

• dict (str, optional) – marker type, defaults to “4x4_1000”

• K (ndarray(3,3), optional) – camera intrinsics, defaults to None

• side (float, optional) – side length of the marker, defaults to None

Returns:

markers found in image

Return type:

list of Fiducial instances

Find ArUco or ApriTag markers in the scene and return a list of Fiducial objects, one per marker. If camera intrinsics are provided then also compute the marker pose with respect to the camera.

dict specifies the marker family or dictionary and describes the number of bits in the tag and the number of usable unique tags.

dict	tag type	marker size	number of unique tags
4x4_50	Aruco	4x4	50
4x4_100	Aruco	4x4	100
4x4_250	Aruco	4x4	250
4x4_1000	Aruco	4x4	1000
5x5_50	Aruco	5x5	50
5x5_100	Aruco	5x5	100
5x5_250	Aruco	5x5	250
5x5_1000	Aruco	5x5	1000
6x6_50	Aruco	6x6	50
6x6_100	Aruco	6x6	100
6x6_250	Aruco	6x6	250
6x6_1000	Aruco	6x6	1000
7x7_50	Aruco	7x7	50
7x7_100	Aruco	7x7	100
7x7_250	Aruco	7x7	250
7x7_1000	Aruco	7x7	1000
original	Aruco	?	?
16h5	AprilTag	4x4	30
25h9	AprilTag	5x5	35
36h10	AprilTag	6x6	?
36h11	AprilTag	6x6	587

Example:

Traceback (most recent call last):
  File "<input>", line 1, in <module>
NameError: name 'fiducials' is not defined

Note:

side is the dimension of the square that contains the small white squares inside the black background.

References:

• Robotics, Vision & Control for Python, Section 13.6.1, P. Corke, Springer 2023.

Seealso:

Fiducial