If the signature is not its own object, its part of another one.
Now you have a situation where the signature is an image, part of a bigger image. You cannot remove it using iTextSharp alone.
You'd get the object that it's a part of, export that, do some image editing to "paint over" the signature, then use iTextSharp to replace the image in the PDF with the edited one.
If you're trying to do this automated, you're going to have an extremely difficult time getting the code to identify the signature and, just as difficult, separating that from the line that the signature is on.
Good luck. You're going to need it as I can't find a single example of anyone doing this.
The following Function gets called by a program running on several station in a workgroup. The file resides on a shared resources. I need to make this routine network safe so only one station can read and write the file at a time. The other stations should just wait until the file is not in use. I assume I must attempt open the file for read write access and lock other users out of the file. Not sure how this is done in C#