boogie

PImage img;
int f, step = 5;

void setup() {
  img = loadImage("tmp-0.gif");
  size(img.width, img.height);
  background(0);
  noStroke();
}

void draw() {
  convPic();
  if (frameCount==171) noLoop();
}

void convPic() {
  background(255);
  img = loadImage("tmp-"+(frameCount-1)+".gif");
  for (int x=0; x<width; x += step) {
    for (int y=0; y<height; y+= step) {
      color col = img.get(x, y);
      f= brightness(col)>150?255:0;
      fill(f);
      ellipse(x, y, step, step);
    }
  }
  saveFrame("image-###.gif");
}