title: Optimal Parameters for haarclassifiers
body: <p>I am trying to detect faces and pedestrians using the provided xml files, <code>haarcascade_frontalface_alt</code> and <code>hogcascade_pedestrians.xml</code>. So far i can get some detection, however the pedestrian detection is pretty poor, and the face detection is average. I am doing it on the iphone with 640x480 or 480x640 images. I can make the images bigger as well however the processing takes faster. Also i might move the processing to a server, however the question remains the same. As of now I am doing this to get the results.</p>
  
  <p>Faces: this first one below doesnt even work. it wont compile. </p>
  
  <pre><code>faceDetector.detectMultiScale(matgrey, faces, 1, 1, 2, 0|CV_HAAR_SCALE_IMAGE, cv::Size(30,30));
  </code></pre>
  
  <p>So I've resorted to the function call below. </p>
  
  <pre><code>faceDetector.detectMultiScale(matgrey, faces);
  </code></pre>
  
  <p>Pedestrians: </p>
  
  <pre><code>hog.detectMultiScale(rgbMat, found, 0, cv::Size(8,8), cv::Size(32,32), 1.05, 2);
  </code></pre>
  
  <p>I really would like to increase the results quality. I was curious if changing the parameters for this would enhance the results. I want optimal results so processing time isn't a huge problem.</p>
  
  <p>Thanks and any feed back would be awesome.</p>