c - Draw rectangle over optical flow feature points -

i want draw rectangle on feature points optical flow process. i'm using cvseqpush method draw it:

cvseq* trackcarcontour = cvcreateseq(cv_32fc2, sizeof(cvseq), sizeof(cvpoint2d32f), contour_storage ); for(int i=0;i<numberoffeaturesfound;i++) {     cvseqpush( trackcarcontour, &cur_feature[i] ); } cvrect trackcarrect = cvboundingrect(trackcarcontour, 0); 

however, rectangle drawn not bound on points, instead shows on top left corner of image.

is there other way this? or, what's wrong way of doing this?