iTextSharp Image Bring To Front - image

Question

Building a document generation system for our web app and am branding the document as required. The document is designed in powerpoint and printed to via NitroPdf. The first page is a large image essentially, with a white area in the image.
I am attempting to place the branding logo in the whitespace allocated. Positioning is ok, however, my branding image is appearing behind the PDF'd document full page image.
Having googled, i can't seem to find a 'z-index' type function... would have thought i wouldn't be the only one with the issue?
Section of code adding the image is as follows:
image.ScaleToFit(width, height);
image.SetDpi(300, 300);
// Position the logo.
image.SetAbsolutePosition(fromLeft, fromBottom);
// Add the image.
document.Add(image);

Answer 1

It is very strange that you would need the following line to add an image to an existing PDF:
document.Add(image);
It's as if you're using PdfWriter instead of PdfStamper, which would be very strange.
Perhaps you overlooked the documentation or maybe you didn't search StackOverflow before you started writing your code: How can I insert an image with iTextSharp in an existing PDF?
using System.IO;
using iTextSharp.text;
using iTextSharp.text.pdf;
class Program
{
static void Main(string[] args)
{
using (Stream inputPdfStream = new FileStream("input.pdf", FileMode.Open, FileAccess.Read, FileShare.Read))
using (Stream inputImageStream = new FileStream("some_image.jpg", FileMode.Open, FileAccess.Read, FileShare.Read))
using (Stream outputPdfStream = new FileStream("result.pdf", FileMode.Create, FileAccess.Write, FileShare.None))
{
var reader = new PdfReader(inputPdfStream);
var stamper = new PdfStamper(reader, outputPdfStream);
var pdfContentByte = stamper.GetOverContent(1);
Image image = Image.GetInstance(inputImageStream);
image.SetAbsolutePosition(100, 100);
pdfContentByte.AddImage(image);
stamper.Close();
}
}
}
You may have found examples where GetUnderContent() is used. This adds content under the existing content. If you want the content to cover the existing content, you need GetOverContent() as is shown in the code sample.

Answer 2

Maybe it's a bit late, but I've faced with the same issue and I've solved with a workaround with Paragraphs (hereunder the code in Visual Basic):
Public Class PDF
Public Doc As Document
Public Writer As PdfWriter
Public Cb As PdfContentByte
Public Sub setFrontImage(ByVal _appendImg As String, align As Integer, x As Integer, y As Integer, ByVal w As Integer, h As Integer, _leading As Integer)
Dim ct As New ColumnText(Cb)
Dim ph As Phrase
Dim ch As Chunk
Dim p As Paragraph = new Paragraph()
Dim image As iTextSharp.text.Image = iTextSharp.text.Image.GetInstance(_appendImg)
image.ScaleAbsolute(w, h)
p.Add(new Chunk(image,x,y))
ct.SetSimpleColumn(p,x, y, w, h, _leading, align)
ct.Go()
End Sub
End Class
I saw you used the absolute position to put your logo up your image so am I, consider to modify the usage of Chunk with width and height if you don't need to fit it inside a restricted space.