How can I reduce false positives when using the "readAprilTag" function?

I have an image that contains an AprilTag. When I use the "readAprilTag" function, MATLAB correctly identifies the AprilTag, but also picks up an extraneous AprilTag in the background of the image.

How can I reduce the number of false positives that the "readAprilTag" function returns?

Answer 1

[MathWorks Support Team]

The easiest way to assist in accurate AprilTag detection is to increase the contrast or brightness of the image. Please refer to the following example, where "I" refers to the image:

 

I = I + 70;                   % Increases the contrast of the image
I = imadjust(I, [], [], 0.2); % Increases the brightness of the image

Alternatively, try measuring the area of the AprilTag using the returned "loc" data. False positive AprilTags will most likely have different size from true positive AprilTags. That may allow for easy filtering.