Image Processing in Java | Set 10 ( Watermarking an image )

We strongly recommend to refer below post as a prerequisite of this.

In this set we will be generating a watermark and apply it on an input image.
For generating a text and applying it in an image we will use java.awt.Graphics package. Font and color of text is applied by using java.awt.Color and java.awt.Font classes.

Some of the methods used in the code:

getGraphics() – This method is found in BufferedImage class, and it returns a 2DGraphics object out of image file.
drawImage(Image img, int x, int y, ImageObserver observer) – The x,y location specifies the position for the top-left of the image. The observer parameter notifies the application of updates to an image that is loaded asynchronously. The observer parameter is not frequently used directly and is not needed for the BufferedImage class, so it usually is null.
setFont(Font f) – This method is found in Font class of awt package and the constructor takes (FONT_TYPE, FONT_STYLE, FONT_SIZE) as arguments.
setColor(Color c) – This method is found in Color class of awt package and the constructor takes (R, G, B, A) as arguments.
drawString(String str, int x, int y) – Fond in Graphics class takes the string text and the location cordinates as x and y as arguments.

// Java code for watermarking an image 
  
// For setting color of the watermark text 
import java.awt.Color; 
  
// For setting font of the watermark text 
import java.awt.Font; 
  
import java.awt.Graphics; 
import java.awt.image.BufferedImage; 
import java.io.File; 
import java.io.IOException; 
  
import javax.imageio.ImageIO; 
  
public class WaterMark 
{ 
    public static void main(String[] args) 
    { 
        BufferedImage img = null; 
        File f = null; 
  
        // Read image 
        try
        { 
            f = new File("input.png"); 
            img = ImageIO.read(f); 
        } 
        catch(IOException e) 
        { 
            System.out.println(e); 
        } 
  
        // create BufferedImage object of same width and 
        // height as of input image 
        BufferedImage temp = new BufferedImage(img.getWidth(), 
                    img.getHeight(), BufferedImage.TYPE_INT_RGB); 
  
        // Create graphics object and add original 
        // image to it 
        Graphics graphics = temp.getGraphics(); 
        graphics.drawImage(img, 0, 0, null); 
  
        // Set font for the watermark text 
        graphics.setFont(new Font("Arial", Font.PLAIN, 80)); 
        graphics.setColor(new Color(255, 0, 0, 40)); 
  
        // Setting watermark text 
        String watermark = "WaterMark generated"; 
  
        // Add the watermark text at (width/5, height/3) 
        // location 
        graphics.drawString(watermark, img.getWidth()/5, 
                                   img.getHeight()/3); 
  
        // releases any system resources that it is using 
        graphics.dispose(); 
  
        f = new File("output.png"); 
        try
        { 
            ImageIO.write(temp, "png", f); 
        } 
        catch (IOException e) 
        { 
            System.out.println(e); 
        } 
    } 
} 

NOTE:Code will not run on online ide since it requires image in drive.

Output:

input.jpg



output.jpg

Please write comments if you find anything incorrect, or you want to share more information about the topic discussed above.

Image Processing in Java | Set 10 ( Watermarking an image )

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