processing4/java/examples/Basics/Image/BackgroundImage/applet/BackgroundImage.java

import processing.core.*; 

import java.applet.*; 
import java.awt.*; 
import java.awt.image.*; 
import java.awt.event.*; 
import java.io.*; 
import java.net.*; 
import java.text.*; 
import java.util.*; 
import java.util.zip.*; 
import java.util.regex.*; 

public class BackgroundImage extends PApplet {

/**
 * Background Image. 
 * 
 * This example presents the fastest way to load a background image
 * into Processing. To load an image as the background, it must be
 * the same width and height as the program.
 */
 
PImage bg;
int a; 

public void setup() 
{
  size(200,200);
  frameRate(30);
  // The background image must be the same size as the parameters
  // into the size() method. In this program, the size of "milan_rubbish.jpg"
  // is 200 x 200 pixels.
  bg = loadImage("milan_rubbish.jpg");
}

public void draw() 
{
  background(bg);

  a = (a + 1)%(width+32);
  stroke(226, 204, 0);
  line(0, a, width, a-26);
  line(0, a-6, width, a-32);
}

  static public void main(String args[]) {
    PApplet.main(new String[] { "BackgroundImage" });
  }
}