sksurgeryarucotracker.algorithms.compare_matrices module

A utility for comparing tracking matrices

sksurgeryarucotracker.algorithms.compare_matrices.matrices_equivalent(mat_a, mat_b, cube_length=500.0, tolerance=5.0)

Helper function to check the equivalence of 2 matrices. Because the 3x3 rotation and the 1X3 translation can have very different magnitudes we want something a bit more nuances than just np.allclose for the whole matrix. np.allclose worked OK until opencv-contrib-python > 4.5.1 see Issue scikit-surgerybard Issue #69 and scikit-surgeryarucotracker issue #41

Rather than comparing matrices let’s look at what happens when we apply them to point cooridinates. If we define an operating cube, with the camera at the centre of the plane defined by the x and y axes and z = 0, by testing the differences at the extremities of that cube we can say that sksArucoTracker is accurate to within x mm over a volume of side length x mm. By default 5.0 mm and 500 mm.

This isn’t very accurate but mainly seems to be due to instability in opencv-contrib-python. If you wanted more accuracy for a given application you could version lock opencv-contrib-python