Java by API/java.awt/Transparency

Transparency.BITMASK

  
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.BITMASK);
  }
}

Transparency.OPAQUE

  
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();
    // Create an image that does not support transparency
    BufferedImage bimage = gc.createCompatibleImage(100, 100, Transparency.OPAQUE);
  }
}

Transparency.TRANSLUCENT

  
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);
  }
}