CascadeClassifier::detectMultiScale function

Hello, I just learned how to use CascadeClassifier::detectMultiScale function to detect human face(http://docs.opencv.org/2.4/doc/tutorials/objdetect/cascade_classifier/cascade_classifier.html), and I want to separate it into two step, let client extracts the features and send to the server ,then server detect the faces, does any one know how to do this? Really thanks.