Code Sample: Convert PDF page into BufferedImage in Java

A Java program that gets images from a PDF (one image per page) as Java BufferedImage objects using Qoppa’s library jPDFImages. Once images are available as BufferedImage objects, they can easily be modified before saving using Java Graphics2D. For instance here a watermark is applied to the images.

Sample code, which uses jPDFImages library but can also be changed to use jPDFProcess or jPDFViewer.

// Load the document
PDFImages pdfDoc = new PDFImages ("input.pdf", null);
 
// Loop through pages
for (int count = 0; count < pdfDoc.getPageCount(); ++count)
{
// Get an image of the PDF page at a resolution of 150 DPI 
BufferedImage pageImage = pdfDoc.getPageImage(count, 150);
 
// create a Graphics 2D from the page image	
Graphics2D g2d = pageImage.createGraphics();
 
// BufferedImage can be modified using all drawing functions available in Graphics2D
// here is an example on how to add a watermark
g2d.setFont (new Font ("sansserif", Font.PLAIN, 200));
g2d.rotate(Math.toRadians(45));
g2d.setColor (new Color (128, 128, 128, 128));
g2d.drawString ("Watermark", 300, g2d.getFontMetrics().getMaxDescent());
 
// Save the image as a JPEG
File outputFile = new File ("output_" + count + ".jpg");
ImageIO.write(pageImage, "JPEG", outputFile);

http://www.qoppa.com/pdfimages/guide/sourcesamples/PDFToBufferedImages.java

If your goal is only to add a watermark, you may also look at this simple sample:
http://www.qoppa.com/pdfimages/guide/sourcesamples/Watermark.java 

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