// open the background as input stream
InputStream inputStream = getAssets().open("background.jpg");

// create a bitmap
final Bitmap bitmap = BitmapFactory.decodeStream(inputStream);

// create an NPOT texture
final NPOTTexture npotTexture = new NPOTTexture(bitmap.getWidth(),
            bitmap.getHeight(), RGBColor.BLACK);

// set the effect
npotTexture.setEffect(new ITextureEffect() {

   @Override
   public void init(Texture texture) {
   }

   @Override
   public boolean containsAlpha() {
      return false;
   }

   @Override
   public void apply(int[] dest, int[] source) {
                // we apply the effect, but really all we do is copying the ARGB from the bitmap to "dest"
      bitmap.getPixels(dest, 0, bitmap.getWidth(), 0, 0,
            bitmap.getWidth(), bitmap.getHeight());
   }
});

// apply the effect
npotTexture.applyEffect();

// now render everything..
frameBuffer.clear(..)
frameBuffer.blit(npotTexture, 0, 0, 0, 0,
         bitmap.getWidth(), bitmap.getHeight(),
         FrameBuffer.OPAQUE_BLITTING);

world.renderScene(frameBuffer);
world.draw(frameBuffer);
frameBuffer.display();