c++ - How to get keyPoint ID -

i'm doing matching programm in opencv , c++ , want classifier keypoints-detected depending of region of image are.

i.e: if detect keypoint in top of image want classifier in region 1... depending found keypoints want classifier them.

finally i'm going new classifier vector this:

vector classifier_vector;

and 1 of 2 parameters need id of every detected points.

does know how can keypoints id?

i'm not sure next saw parameter need

int _class_id

am right?

thanks everybody. ;)

opencv have keypoint class have following parameters:

pt (x,y) -> position of keypoints, size - size of keypoint, angle - orientation of keypoint, response - strength of keypoint, octave - number of octave layer keypoint detected, class_id - number of object keypoint belongs to.

so need class_id.

keypoint kpt; kpt.class_id;