How to combine multiple PNGs into one big PNG file?

Question

I have approx. 6000 PNG files (256*256 pixels) and want to combine them into a big PNG holding all of them programmatically.

What\'s the best/fastest way to do that?

Answer 1

Combing Images

private static void combineALLImages(String screenNames, int screens) throws IOException, InterruptedException {
    System.out.println("screenNames --> D:\\screenshots\\screen   screens --> 0,1,2 to 10/..");
    int rows = screens + 1;
    int cols = 1;
    int chunks = rows * cols ; 

     File[] imgFiles = new File[chunks];
    String files = "";
    for (int i = 0; i < chunks; i++) {
        files = screenNames + i + ".jpg";
        imgFiles[i] = new File(files);          
        System.out.println(screenNames + i + ".jpg"+"\t Screens : "+screens);    

    }

    BufferedImage sample = ImageIO.read(imgFiles[0]);
    //Initializing the final image
    BufferedImage finalImg = new BufferedImage(sample.getWidth() * cols, sample.getHeight() * rows, sample.getType());

    int index = 0;
    for (int i = 0; i < rows; i++) {
        for (int j = 0; j < cols; j++) {
            BufferedImage temp = ImageIO.read(imgFiles[index]);
            finalImg.createGraphics().drawImage(temp, sample.getWidth() * j, sample.getHeight() * i, null);
            System.out.println(screenNames + index + ".jpg");
            index++;
        }
    }
    File final_Image = new File("D:\\Screenshots\\FinalImage.jpg");
    ImageIO.write(finalImg, "jpeg", final_Image);

}