pyramid strategy fails for sparse optical flow

[ahsteven]

I am running the tracker on several videos. However sometimes the gmc sparse optical flow fails. I get this error:

File BoTSORT/tracker/gmc.py", line 72, in apply
return self.applySparseOptFlow(raw_frame, detections)
File "BoTSORT/tracker/gmc.py", line 268, in applySparseOptFlow
matchedKeypoints, status, err = cv2.calcOpticalFlowPyrLK(self.prevFrame, frame, self.prevKeyPoints, None)
cv2.error: OpenCV(4.7.0) /io/opencv/modules/video/src/lkpyramid.cpp:1394: error: (-215:Assertion failed) prevPyr[level * lvlStep1].size() == nextPyr[level * lvlStep2].size() in function 'calc'

The video input size was 1080,1920,3

if I cannot use sparse optical flow what other setting do you recommend for gmc? 'orb', 'ecc', 'sift'?