I want to try out the new matching algorithm in flann, with LSH. But there is no info available.
What is the significance of the parameters in the
LshIndexParams(int table_number, int key_size, int multi_probe_level);
Also, can you suggest some default values to start with? For a better context, I want to replace the
BruteForceMatcher<Hamming> in the FREAK sample.
I would also want to know whether I should instantiate the matcher with a custom
I have tried to set the parameters recommended by docs (and some random combinations):
FlannBasedMatcher matcher2(new flann::LshIndexParams(20,10,2));
but it throws an error inside miniflann :
answered 2012-07-20 02:47:35 -0600Maria Dimashova
I reproduced your problem. It's a bug in the LshIndex constuctor with its members types in lines 93-95 of lsh_index.h. 'unsigned' type has to be there instead of 'int'. It works for me with this fix. But I can not put the fix to the OpenCV repo because it's read-only now. Please open an issue on OpenCV redmine when it'll be also available to be sure that I have not forgotten to fix it.
answered 2012-07-18 19:33:32 -0600Vincent Rabaud
Those parameters are the ones of the LSH multi-probe algorithm but its implementation is only for binary features right now. I'll add that to the docs. What is the type of the FREAK features ? (floats ? binary ?).
My guess is that the cast error you get is because the type is not binary.
Asked: 2012-07-18 12:08:40 -0600
Seen: 8,714 times
Last updated: Jul 20 '12