AveragePointTracking

// Daniel Shiffman
// Tracking the average location beyond a given depth threshold
// Thanks to Dan O'Sullivan

// https://github.com/shiffman/OpenKinect-for-Processing
// http://shiffman.net/p5/kinect/

import org.openkinect.freenect.*;
import org.openkinect.processing.*;

// The kinect stuff is happening in another class
KinectTracker tracker;
Kinect kinect;


void setup() {
  size(640, 520);
  kinect = new Kinect(this);
  tracker = new KinectTracker();
}

void draw() {
  background(255);

  // Run the tracking analysis
  tracker.track();
  // Show the image
  tracker.display();

  // Let's draw the raw location
  PVector v1 = tracker.getPos();
  fill(50, 100, 250, 200);
  noStroke();
  ellipse(v1.x, v1.y, 20, 20);

  // Let's draw the "lerped" location
  PVector v2 = tracker.getLerpedPos();
  fill(100, 250, 50, 200);
  noStroke();
  ellipse(v2.x, v2.y, 20, 20);

  // Display some info
  int t = tracker.getThreshold();
  fill(0);
  text("threshold: " + t + "    " +  "framerate: " + int(frameRate) + "    " +
    "UP increase threshold, DOWN decrease threshold", 10, 500);
}

// Adjust the threshold with key presses
void keyPressed() {
  int t = tracker.getThreshold();
  if (key == CODED) {
    if (keyCode == UP) {
      t+=5;
      tracker.setThreshold(t);
    } else if (keyCode == DOWN) {
      t-=5;
      tracker.setThreshold(t);
    }
  }
}

/ Daniel Shiffman
// Tracking the average location beyond a given depth threshold
// Thanks to Dan O'Sullivan

// https://github.com/shiffman/OpenKinect-for-Processing
// http://shiffman.net/p5/kinect/

class KinectTracker {

  // Depth threshold
  int threshold = 505;

  // Raw location
  PVector loc;

  // Interpolated location
  PVector lerpedLoc;

  // Depth data
  int[] depth;

  // What we'll show the user
  PImage display;

  KinectTracker() {
    // This is an awkard use of a global variable here
    // But doing it this way for simplicity
    kinect.initDepth();
    kinect.enableMirror(true);
    // Make a blank image
    display = createImage(kinect.width, kinect.height, RGB);
    // Set up the vectors
    loc = new PVector(0, 0);
    lerpedLoc = new PVector(0, 0);
  }

  void track() {
    // Get the raw depth as array of integers
    depth = kinect.getRawDepth();

    // Being overly cautious here
    if (depth == null) return;

    float sumX = 0;
    float sumY = 0;
    float count = 0;

    for (int x = 0; x < kinect.width; x++) {
      for (int y = 0; y < kinect.height; y++) {

        int offset =  x + y*kinect.width;
        // Grabbing the raw depth
        int rawDepth = depth[offset];

        // Testing against threshold
        if (rawDepth < threshold) {
          sumX += x;
          sumY += y;
          count++;
        }
      }
    }
    // As long as we found something
    if (count != 0) {
      loc = new PVector(sumX/count, sumY/count);
    }

    // Interpolating the location, doing it arbitrarily for now
    lerpedLoc.x = PApplet.lerp(lerpedLoc.x, loc.x, 0.3f);
    lerpedLoc.y = PApplet.lerp(lerpedLoc.y, loc.y, 0.3f);
  }

  PVector getLerpedPos() {
    return lerpedLoc;
  }

  PVector getPos() {
    return loc;
  }

  void display() {
    PImage img = kinect.getDepthImage();

    // Being overly cautious here
    if (depth == null || img == null) return;

    // Going to rewrite the depth image to show which pixels are in threshold
    // A lot of this is redundant, but this is just for demonstration purposes
    display.loadPixels();
    for (int x = 0; x < kinect.width; x++) {
      for (int y = 0; y < kinect.height; y++) {

        int offset = x + y * kinect.width;
        // Raw depth
        int rawDepth = depth[offset];
        int pix = x + y * display.width;
        if (rawDepth < threshold) {
          // A red color instead
          display.pixels[pix] = color(150, 50, 50);
        } else {
          display.pixels[pix] = img.pixels[offset];
        }
      }
    }
    display.updatePixels();

    // Draw the image
    image(display, 0, 0);
  }

  int getThreshold() {
    return threshold;
  }

  void setThreshold(int t) {
    threshold =  t;
  }
}