static final int SIZE = 200;
static final int HSIZE = 100;

// double buffers
PGraphics front;

void setup() {
  size(SIZE, SIZE, P2D);
  front = createGraphics(SIZE, SIZE, P2D);
  frameRate(20);
}

void draw() {
  
  int x = (int)random(-5, 5);
  int y = (int)random(-5, 5);
  int r = (int)random(128, 255);
  int g = (int)random(128, 255);
  int b = (int)random(128, 255);
  
  front.beginDraw();
  front.translate(HSIZE, HSIZE);  // move origin to centre
  // copy saved image to foreground, twisted and a bit larger
  front.rotate(.02);
  front.scale(1.06);
  // copy from current image
  front.image(this.g, -HSIZE, -HSIZE, SIZE + 1, SIZE + 1);
  // draw something new on screen
  front.fill(r, g, b);
  front.noStroke();
  front.rectMode(CENTER);
  front.ellipse(x, y, 5, 5);
  front.endDraw();
  
  // copy image to screen
  image(front, 0, 0);
}