tagStandard41h12 Segmentation fault (core dumped)

[TON14]

Detecting tagStandard41h12 AprilTag library compiled from source

at_detector = Detector(searchpath=['/usr/local/lib'],
                       families='tagStandard41h12',
                       nthreads=1,
                       quad_decimate=1.0,
                       quad_sigma=0.0,
                       refine_edges=1,
                       decode_sharpening=0.25,
                       debug=0)

Output

[]
Segmentation fault (core dumped)

When change nthreads=1 to nthreads=2

at_detector = Detector(searchpath=['/usr/local/lib'],
                       families='tagStandard41h12',
                       nthreads=2,
                       quad_decimate=1.0,
                       quad_sigma=0.0,
                       refine_edges=1,
                       decode_sharpening=0.25,
                       debug=0)

Output

[]

My image

[pfaion]

Hi @TON14 can you try removing the searchpath keyword from the Detector() initialization and see if it works?

This keyword is actually not needed anymore in the adjusted wrapper that we are providing. We are internally shipping the original apriltag libraries as part of the python package and thus know where the searchpath is.

[TON14]

@pfaion

at_detector = Detector(families='tagStandard41h12',
                       nthreads=1,
                       quad_decimate=1.0,
                       quad_sigma=0.0,
                       refine_edges=1,
                       decode_sharpening=0.25,
                       debug=1
)

Debug images were created. Now with nthreads=1 no error Segmentation fault (core dumped). But 0 tag founded Output []

[TON14]

LOL =) i print tagStandard52h13 tags but try detect tagStandard41h12

True Solution remove the searchpath keyword from the Detector()

Please update info on https://pypi.org/project/pupil-apriltags/

[pfaion]

@TON14 Glad to hear this fixed the issue. The README is already updated on GitHub from #18 Guess we'll have to push a new release to PyPI for updating the docs there as well 😞