Dear All, I implement OpenCV face detection in iPhone 4. When I look at the time taken for the implementation of the function face_cascade->detectMultiScale(*grayMat, faces, haar_scale, haar_minNeighbors, haar_flags, haar_minSize ); It takes nearly 120msec. I can't tolerate that amount of time for my application. How can I improve the performance to reduce the processng time? My configurations are float haar_scale = 1.15; int haar_minNeighbors = 3; int haar_flags = 0 | CV_HAAR_SCALE_IMAGE | CV_HAAR_DO_CANNY_PRUNING; cv::Size haar_minSize = cvSize(60, 60); Thanks. Thomas