Positioning A4 image as page inside PDF file using pdfbox

SexyMF :

I have a file jpg file: 2480 x 3508 pixels which is the suitable size for 4A. I need to put this file in a pdf.

PDDocument doc = new PDDocument();
ByteArrayOutputStream os = new ByteArrayOutputStream();
InputStream certificate = getClass().getResourceAsStream("certificate.jpg");
BufferedImage bi = ImageIO.read(certificate);
PDPage page = new PDPage(PDRectangle.A4);//<<---- A4
doc.addPage(page);

PDImageXObject pdImageXObject = LosslessFactory.createFromImage(doc, bi);
PDPageContentStream contentStream = new PDPageContentStream(doc, page, 
PDPageContentStream.AppendMode.APPEND, false);
contentStream.drawImage(pdImageXObject, 0, -10);
contentStream.close();
doc.save( "c://appfiles//PDF_image.pdf" );
doc.close();

The problem is that the generated file is totally off and not fitting the A4 size in the PDF.

The source file: https://i.stack.imgur.com/a0ZHG.jpg
The generated File: https://www.dropbox.com/s/ufo3246b6eoz3f5/PDF_image.pdf?dl=1

I know I can play with the width and height but then the printing quality drops and I think the PDRectangle.A4 was intended to prevent these kind of manipulations.

How can I make the 2480 x 3508 pixels fit to PDRectangle.A4 pdf page?

Thanks

Tilman Hausherr :

The dimensions of PDF are on 72 dpi,

System.out.println(PDRectangle.A4); // output is [0.0,0.0,595.27563,841.8898]

your image is 300 dpi, so you have to scale:

contentStream.drawImage(pdImageXObject, 0f, -10f, 
        pdImageXObject.getWidth() / 300f * 72, 
        pdImageXObject.getHeight() / 300f * 72);

I also recommend to use JPEGFactory.createFromStream(), this is faster, smaller and uses the jpeg stream directly. Your result PDF file is 580 KB instead of 2555 KB.