Kinect Hand Tracking

import SimpleOpenNI.*;
SimpleOpenNI kinect;
float youAre = 0;

PImage handImage;
int imageHeight = 1787;
int imageWidth = 833;

void setup() {
  kinect = new SimpleOpenNI(this);
  kinect.enableDepth();
  kinect.enableUser(SimpleOpenNI.SKEL_PROFILE_ALL);
  kinect.setMirror(true);
  kinect.enableRGB();

  size(640, 480);
  smooth();


  handImage = loadImage("Hand.png");

}
void draw() {
  kinect.update();
  image(kinect.rgbImage(), 0, 0);
  IntVector userList = new IntVector();
  kinect.getUsers(userList);

  if (userList.size() > 0) {
    int userId = userList.get(0);

   // if ( kinect.isTrackingSkeleton(userId)) {
      //drawSkeleton(userId);
   // }

    float rightArmAngle = getJointAngle(userId, SimpleOpenNI.SKEL_RIGHT_HAND, SimpleOpenNI.SKEL_RIGHT_ELBOW);
    PVector handPos = new PVector();
    kinect.getJointPositionSkeleton(userId, SimpleOpenNI.SKEL_RIGHT_HAND, handPos);

    float newImageWidth = map(handPos.z, 500, 2000, imageWidth/6, imageWidth/11);
    float newImageHeight = map(handPos.z, 500, 2000, imageHeight/6, imageHeight/11);


     PVector convertedHandPos = new PVector();
     kinect.convertRealWorldToProjective(handPos, convertedHandPos);

    pushMatrix();
      translate(convertedHandPos.x, convertedHandPos.y);
      rotate(rightArmAngle*-1);
      rotate(PI/2);
      image(handImage, -1 * (newImageWidth/2), 0 - (newImageHeight/2), newImageWidth, newImageHeight);
    popMatrix();
  }
}

float getJointAngle(int userId, int jointID1, int jointID2) {
  PVector joint1 = new PVector();
  PVector joint2 = new PVector();
  kinect.getJointPositionSkeleton(userId, jointID1, joint1);
  kinect.getJointPositionSkeleton(userId, jointID2, joint2);
  return atan2(joint1.y-joint2.y, joint1.x-joint2.x);
}

// user-tracking callbacks!
void onNewUser(int userId) {
  println("start pose detection");
  kinect.startPoseDetection("Psi", userId);
}
void onEndCalibration(int userId, boolean successful) {
  if (successful) {
    println(" User calibrated !!!");
    kinect.startTrackingSkeleton(userId);
  }
  else {
    println(" Failed to calibrate user !!!");
    kinect.startPoseDetection("Psi", userId);
  }
}
void onStartPose(String pose, int userId) {
  println("Started pose for user");
  kinect.stopPoseDetection(userId);
  kinect.requestCalibrationSkeleton(userId, true);
}