Create an image that supports arbitrary levels of transparency from GraphicsConfiguration : GraphicsEnvironment « 2D Graphics « Java Tutorial

1. Java Tutorial
2. 2D Graphics
3. GraphicsEnvironment

import java.awt.GraphicsConfiguration;
import java.awt.GraphicsDevice;
import java.awt.GraphicsEnvironment;
import java.awt.Transparency;
import java.awt.image.BufferedImage;

public class Main {
  public static void main(String[] argv) throws Exception {
    GraphicsEnvironment ge = GraphicsEnvironment.getLocalGraphicsEnvironment();
    GraphicsDevice gs = ge.getDefaultScreenDevice();
    GraphicsConfiguration gc = gs.getDefaultConfiguration();

    BufferedImage bimage = gc.createCompatibleImage(100, 100, Transparency.TRANSLUCENT);
  }
}