Animation test;
BFont font;

void setup()
{
  size(400,100);
  font = loadFont("RotisSanSer.vlw.gz");
  textFont(font, 20);
 
  test = new Animation(this, loadImage("image.gif"), 100,40, 200,40);
  test.showRectangle();
}

void loop()
{
  background(127);
  
  if (test.currentRepetition() % 2 == 1)
    test.setImageHeight(30); // make image 30px high
  else
     test.setImageHeight(10); // make image 10px high

  test.draw();
  float img_height = test.imageHeight();
  text("Image height is " + img_height + " pixels.", 25, 25);    
}