Removing PDF invisible objects with iTextSharp

If the PDF which you are trying is a template/predefined/fixed then you can remove that object by calling RemoveField.

PdfReader pdfReader = new PdfReader(../Template_Path.pdf"));
PdfStamper pdfStamperToPopulate = new PdfStamper(pdfReader, new FileStream(outputPath, FileMode.Create));
AcroFields pdfFormFields = pdfStamperToPopulate.AcroFields;
pdfFormFields.RemoveField("fieldNameToBeRemoved");