first of all I'm new so sorry for any mistake. im trying to compute a similarity score between two images based on the number of inliers in order to put the most similar one on top. I read about ransac method and I tried the one from skimage library. the problem Is that its too slow, almost 12 second for each query match (1 query and 25 image to be reranked for that query). So I read something new on OpenCV which use something called UsacParam which should be faster and more precise. The question is how do I use it? I tried to do this:

import cv2
_, inliers = cv2.findFundamentalMat(locations_1_to_use,locations_2_to_use,cv2.USAC_FAST)`
inliers = sum(np.ravel(inliers))`

but I have some problem with that cv2.USAC_FAST it tells me it doesn't exist but according to this link