This is an adaption of a processing sketch on learningprocessing.com http://www.learningprocessing.com/exa... The code takes the average of all the movement and moves the ball towards it. Simple really. Check out all the code and try it fro yourself here. Please post video responses if you do something cool with it!

gistfile1.txt

import processing.video.*;

Capture video;

PImage prevFrame;

float threshold = 150;
int Mx = 0;
int My = 0;
int ave = 0;

int ballX = width/2;
int ballY = height/2;
int rsp = 25;

void setup() {
  size(1024,720);
  video = new Capture(this, width, height, 30);
 
  prevFrame = createImage(video.width,video.height,RGB);
}

void draw() {
  

  if (video.available()) {
    
    prevFrame.copy(video,0,0,video.width,video.height,0,0,video.width,video.height); 
    prevFrame.updatePixels();
    video.read();
  }
  
  loadPixels();
  video.loadPixels();
  prevFrame.loadPixels();
  
  Mx = 0;
  My = 0;
  ave = 0;
  
 
  for (int x = 0; x < video.width; x ++ ) {
    for (int y = 0; y < video.height; y ++ ) {
      
      int loc = x + y*video.width;            
      color current = video.pixels[loc];      
      color previous = prevFrame.pixels[loc]; 
      
     
      float r1 = red(current); float g1 = green(current); float b1 = blue(current);
      float r2 = red(previous); float g2 = green(previous); float b2 = blue(previous);
      float diff = dist(r1,g1,b1,r2,g2,b2);
      
      
      if (diff > threshold) { 
        pixels[loc] = video.pixels[loc];
        Mx += x;
        My += y;
        ave++;
      } else {
        
        pixels[loc] = video.pixels[loc];
      }
    }
  }
  fill(255);
  rect(0,0, width, height);
  if(ave != 0){ 
    Mx = Mx/ave;
    My = My/ave;
  }
  if (Mx > ballX + rsp/2 && Mx > 50){
    ballX+= rsp;
  }else if (Mx < ballX - rsp/2 && Mx > 50){
    ballX-= rsp;
  }
  if (My > ballY + rsp/2 && My > 50){
    ballY+= rsp;
  }else if (My < ballY - rsp/2 && My > 50){
    ballY-= rsp;
  }
    
    updatePixels();
    noStroke();
    fill(200,0,0);
    ellipse(ballX, ballY, 50, 50);
    
  
}

hello,
it is nice work... but I do not understand what is rsp means?