lines

ArrayList<Dot> dots;
int num = 7000, d=20, br=180, alpha=40;
int bg=255, s=0;
PImage img;

void setup() {
  img=loadImage("http://media-cache-ec0.pinimg.com/736x/ca/fd/29/cafd29d721cc0302cee4093ec2e34d27.jpg");
  size(img.width, img.height);
  background(bg);
  dots = new ArrayList<Dot>();
  //image(img, 0, 0);
  img.loadPixels();
  for (int i=0; i<num; i++) {
    int x = int(random(width));
    int y = int(random(height));
    if (brightness(img.pixels[x+y*width])<br) {
      dots.add(new Dot(new PVector(x, y)));
    }
  }
  for (Dot d : dots) {
    d.lineBetween();
  }
}

void draw() {}

void keyPressed() {
  save(random(2332)+".jpg");
}

class Dot {

  PVector loc;

  Dot(PVector _loc) {
    loc = _loc;
  }

  void lineBetween() {
    for (int i=0; i<dots.size (); i++) {
      Dot other = (Dot) dots.get(i);
      float distance = loc.dist(other.loc);
      if (distance >0 && distance < d) {
        stroke(s, alpha);
        line(loc.x, loc.y, other.loc.x, other.loc.y);
      }
    }
  }
}