True/false positives
The distance threshold affects performance
•True positives = # of detected matches that are correct
–Suppose we want to maximize these—how to choose threshold?
•False positives = # of detected matches that are incorrect
–Suppose we want to minimize these—how to choose threshold?
http://farm1.static.flickr.com/47/136915456_c6f719ea3f.jpg?v=0 http://farm1.static.flickr.com/133/328570837_37b6289916.jpg?v=0
50
75
200
feature distance
false match
true match