How can I extend the width size in a PNG file?

Question

I am currently working with PNG images and I'm little bit blocked because a task that not sure how to fix...

This is the scenario. I have a PNG file of 655x265 pixels with a barcode inside of it. What I need to do is 'extend' the width of the image just to include a blank zone on the left of the image, just like this:

The problem is that nothing happens with the image dimensions when I execute my code:

public static void main(String[] args)
{
    try
    {
        String path = "C:\\Users\\xxx\\Desktop\\a.png";
        BufferedImage image = ImageIO.read(new File(path));
        resizeImage(path, image.getWidth() + 100, image.getHeight());
        Graphics graphics = image.getGraphics();
        graphics.setColor(Color.BLACK);
        graphics.setFont(new Font("Verdana", Font.PLAIN, 40));
        graphics.drawString("TTT", 5, 250);
        graphics.dispose();
        ImageIO.write(image, "png", new File(path));
        System.out.println("Image created");
    } catch (Exception e)
    {
        System.out.println(e.getMessage());
        e.printStackTrace();
    }
    System.out.println("Fin");
}

public static void resizeImage(String path, int newHeight, int newWidth) throws IOException
{
    File inputFile = new File(path);
    BufferedImage inputImage = ImageIO.read(inputFile);

    BufferedImage outputImage = new BufferedImage(newWidth, newHeight, inputImage.getType());

    Graphics2D graphics = outputImage.createGraphics();
    graphics.drawImage(inputImage, 0, 0, newWidth, newHeight, null);
    graphics.dispose();

    ImageIO.write(outputImage, "png", new File(path));
    inputImage.flush();
    outputImage.flush();
}

Do you know what I am doing wrong? Is one of my first times working with image files and probably I misunderstood something important...

Edit: Solution provides in the comments. Link

Hi @Niklas, correct me if I'm wrong but I think the questions are different. The other question ask about how to resize the image, just to do it larger or shorter, but I am asking how to include an extra section, extend the width of the image but with a new blank section — Inazense, Sep 24 '19 at 09:18
Oh, if you want to insert blank space this is more accurate: https://stackoverflow.com/questions/5836203/java-padding-image — , Sep 24 '19 at 09:19
you are *loading* the image `BufferedImage image =...` then you are passing the path to a method that loads the image itself, changes it's size and writes it back, then after the method call `resizeImage(path, image.getWidth() + 100, image.getHeight());` you continue working on your previously loaded buffered image and write it back to disk. Meaning your method reads, manipulates and writes an image for nothing, because the surrounding code keeps a copy of the original image and overwrites the resized file. — GameDroids, Sep 24 '19 at 09:25
Possible duplicate of [Java padding image](https://stackoverflow.com/questions/5836203/java-padding-image) — Inazense, Sep 24 '19 at 09:32

score 1 · Accepted Answer · answered Sep 24 '19 at 09:30

What you could do is let the method take a BufferedImage, resize it and return it:

public static BufferedImage resizeImage(BufferedImage inputImage, int newHeight, int newWidth){
    BufferedImage outputImage = new BufferedImage(newWidth, newHeight, inputImage.getType());
    Graphics2D graphics = outputImage.createGraphics();
    graphics.drawImage(inputImage, 0, 0, newWidth, newHeight, null);
    graphics.dispose(); 
    outputImage.flush();
    return outputImage;
}

Then continue working on the resized image in your surrounding method:

    String path = "C:\\Users\\xxx\\Desktop\\a.png";
    BufferedImage image = ImageIO.read(new File(path));
    image = resizeImage(image, image.getWidth() + 100, image.getHeight());  // here you replace the image with the new, resized image from your method
    Graphics graphics = image.getGraphics();
    graphics.setColor(Color.BLACK);
    ....

How can I extend the width size in a PNG file?

1 Answers1