I have two pictures
PlanA : I detect SIFT key poitns in picture A and using optical flow to find the corresponding points in picture B
Plan B: but if i detect SIFT key points in picture B and do the match thing between picture A and picture B
What the diffences between Plan A and Plan B
which one is better?
Plan A is motion estimation of the extracted points. Many of the algorithm work by comparing the intensity values in the neighborhood. Lucas Kanade is one good method.
Plan B may not find all points that are in image A.
Plan B is better. Optical flow does not work with sift descriptors. The excellent way of describing a neighborhood is lost in Plan A.
In Plan B: Many of the keypoints in A will not be matched in B. But those matched will have much higher confidence than in A. In Plan A: Approximate matches of the points in A will be found
If A and B are continuous frames from video its profitable to use Plan A as the illumination does not change much in continuous frames of video and also Plan B is high on runtime (computing descriptors takes time), else use Plan B.
Cheers,
