How can I add an image to a PDF at specific x-y coordinates using IText?

Question

I have existing PDFs to which I need to dynamically add an image/images. The image comes from a file upload. Once I have the file uploaded, how can specify where to place the image on the PDF. One code snippet I found does not work correctly. This needs to work for PDFs with any number of pages. From what I understand, absolute positioning is set from the bottom-left corner of the last page of the PDF. If I need an image to be displayed 30 pixels from the top and 50 pixels from the left of page 1, how can I accomplish this? Or, if I need to display an image 50px from the top/100 px from the left on page 2?

I've tried using the code found at http://rip747.wordpress.com/2009/03/26/add-an-image-dynamically-to-a-pdf-with-cf-and-itext/. I've modified it for my needs below:

<cfscript>
    myLeft = 30;
    myTop = 50;
    myPageNum = 1;

    // output buffer to write PDF
    fileIO = createObject("java","java.io.FileOutputStream").init(myOutputPath);

    // reader to read our PDF
    reader = createObject("java","com.lowagie.text.pdf.PdfReader").init(mySourcePath);

    // stamper so we can modify our existing PDF
    stamper = createObject("java","com.lowagie.text.pdf.PdfStamper").init(reader, fileIO);

    // get the content of our existing PDF
    content = stamper.getOverContent(reader.getNumberOfPages());

    // create an image object so we can add our dynamic image to our PDF
    image = createobject("java", "com.lowagie.text.Image");

    // initalize our image
    img = image.getInstance(imgPath);

    x = (reader.getPageSize(1).width() - img.scaledWidth()) - myLeft;
    y = (reader.getPageSize(1).height() - img.scaledHeight()) - myTop;

    // now we assign the position to our image
    img.setAbsolutePosition(javacast("float", x), javacast("float", y));

    // add our image to the existing PDF
    content.addImage(img);

    // flattern our form so our values show
    stamper.setFormFlattening(true);

    // close the stamper and output our new PDF
    stamper.close();

    // close the reader
    reader.close();
</cfscript>

The above code places my image at the top-right corner of page 2 - 50px form the top/30px from the left.

I know I'm close...just need a little help getting this nailed down for my needs.

I've updated my code. This gets the image to the top left corner of page 2 - correct positioning, but I want it on page 1:

x = myLeft;
y = (reader.getPageSize(1).height()) - img.scaledHeight() - myTop;

I thought maybe I needed to add the height of page 1 to get the image up to page 1, but the image completely disappears when I try either of the options below:

// I figure I'll need something like this to handle multi-page docs
y = (reader.getPageSize(1).height() * reader.getNumberOfPages()) - img.scaledHeight() - myTop;

y = reader.getPageSize(1).height() + reader.getPageSize(1).height() - img.scaledHeight() - myTop;

Are your pdf's "portrait" orientation only? IIRC you need to account for rotation with landscape pdf's. Also, always close your fileIO or the file may stay locked. (Assuming you are not on CF8 as Henry mentioned) — Leigh

Mark Storer Mark Storer · Accepted Answer · 2011-06-28T17:39:56

You're getting your "OverContent" from stamper.getOverContent(reader.getNumberOfPages());. The parameter for getOverContent() is the page number. So your code is getting a PdfContentByte for the last page, not the first.

How can I add an image to a PDF at specific x-y coordinates using IText?

3 Answers