Thread: Need help with extracting AlphaComposite from an image

Hi, i'm currently working on a watermark that is invisible using AlphaComposite class. The problem i'm having now is that i'm unable to extract the watermark out from the image after it is save.

package invisibleWatermark;
 
import java.awt.*;
import java.awt.geom.*;
import java.awt.image.*;
 
import java.io.*;
 
 
import javax.imageio.*;
 
import javax.swing.*;
 
public class watermark {
 
	static BufferedImage bufferedImage;
 
 
	static void watermark(){
 
		File upImage = new File(mainMenu.txtLoadImage.getText());
 
		if(!upImage.exists()){
			JOptionPane.showMessageDialog(null, "Please Select an image to be watermark. "); 
		}
		else {
 
			if (mainMenu.txtInputWatermark.getText().isEmpty()){
				JOptionPane.showMessageDialog(null, "Please select a watermark to be use. "); 
 
				return; 
			}
			else{
				ImageIcon oriImage = new ImageIcon(upImage.getPath()); 
 
				bufferedImage = new BufferedImage(oriImage.getIconWidth(), oriImage.getIconHeight(), BufferedImage.TYPE_INT_RGB);
 
		        Graphics2D g2D = (Graphics2D) bufferedImage.getGraphics();
 
		        g2D.drawImage(oriImage.getImage(), 0, 0, null);
 
	            AlphaComposite alpha = AlphaComposite.getInstance(AlphaComposite.SRC_OVER, 0.1f);
 
	            g2D.setComposite(alpha);
	            g2D.setColor(Color.white);
	            g2D.setRenderingHint(RenderingHints.KEY_TEXT_ANTIALIASING, RenderingHints.VALUE_TEXT_ANTIALIAS_ON);
	            g2D.setFont(new Font("Arial", Font.BOLD, 35));
 
	            String watermark = mainMenu.txtInputWatermark.getText();
 
	            FontMetrics fontMetrics = g2D.getFontMetrics();
 
	            Rectangle2D rect2D = fontMetrics.getStringBounds(watermark, g2D);
 
	            g2D.drawString(watermark, (oriImage.getIconWidth() - (int) rect2D
	                            .getWidth()) / 2, (oriImage.getIconHeight() - (int) rect2D
	                            .getHeight()) / 2);
 
	            g2D.dispose();
 
	            embedPopupMenu.embedConfirmMenu(); 
			}
		}
	}
}

Welcome zwei_91

What do you mean by "unable to extract"?
What happens and what does not happen? What do you expect instead?

Originally Posted by jps

Welcome zwei_91

What do you mean by "unable to extract"?
What happens and what does not happen? What do you expect instead?

Hi jps,

Basically i'm creating an application that enable watermark to be embedded invisibly on images, the code above enable me to do that.

But then the other problem i'm having now is that after embedding the watermark invisibly, i'm unable to extract it for verification purpose.

By the way, sorry for my bad English.

Does the code compile?
Is there an error?
Is the output wrong?
Do you even get output?
What happens and what does not happen, on a more specific level than "extracting watermarks".

Your English is better than my German I promise

Originally Posted by jps

Does the code compile?
Is there an error?
Is the output wrong?
Do you even get output?
What happens and what does not happen, on a more specific level than "extracting watermarks".

Your English is better than my German I promise

1. Yes, the code compile
2. No, there is no error
3. No, the output is correct
4. Yes, i got the desire output
5. Problem i'm facing now is that i'm unable to undo the process that the code above perform from the output file save