ground truth

[prbonn]

ground truth

[laebe]

Please have a look at demo4: There we calculate and visualize the ground truth overlap of the very first frame against all others. The central function which actually does the work is com_overlap_yaw(). If you want the ground truth overlap for all frames, you just have to call this function for all frames (which we do not do in the demo as it takes some time).

If you have the ground truth overlaps, you just define a threshold for the overlap value (we used 30% in the paper). All frame pairs with higher overlap are then loop closure candidates. Here you might leave out the last n frames (we use n=100 in the paper) in order not to get loop closures between recent frames.