c#, pdf

I have below codes working fine.
but instead of drop the image into the fixed location (  image.SetAbsolutePosition(100, 100);)

Is it possible to do the look up e.g. if the text called 'signature' is shown on the pdf, then drop the image there on the right side of the 'signature' text?
Or if there is any textbox field called 'signature', drop the image next to it.

Is it possible?

0c8f5c99-4ff8-4863-bb62-3af10ad394a8.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();
        }
    }
}

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