Hi, this is my first time to use your .NET PDF SDK. I am also quite new to c# programming. I have tried to find a solution on your website, but it didn't found any useful article till now. So, hope you can help me out soon.

This is what i am doing. I have installed XsPDF library and I am trying to insert a watermark into the document. Actually, the watermark is just a signature image. My problem is that I cannot simply add watermark images to a specific page of exiting PDF. I do not need to add images to a newly created PDF page. Just loading an existing PDF and add it is what all i need.

I can add text watermark to PDF exiting page now, but it cannot work with image watermark. I can only get the output PDF without the watermark. Certainly, i do something wrong. Hope you get what i say and please help.

This article on XsPDF.com is what are you looking for, check out: Add watermark on PDF in C#.

Answers

Thank you for contacting us. We appreciate your evaluation of our SDK. From what you explain, we can get the following requirements.

• You want to add image watermark at a specific position of PDF page
• You want to add watermark to an existing PDF and do not want to add it to a new page

If yes, there is nothing to worry about. Adding watermarks to an existing PDF file is quite simple. You can easily achieve this by copying the following c# sample code to your project. Simply load a PDF file and the image watermark, customize the position, and save it.

//Load PDF document
PdfDocument document = new PdfDocument("sample.pdf");

//Load watermark image from local file
string watermarkFile = "watermark.png";
var watermarkImg = XImage.FromFile(watermarkFile);

//Add watermark to first page
var page = document.Pages[0];
//The new content will be rendered above the existing graphic.
var gfx = XGraphics.FromPdfPage(page, XGraphicsPdfPageOptions.Append);

//Customize image location
var location = new XPoint(100, 100);

//Watermark the PDF page with image
gfx.DrawImage(watermarkImg, location);
//Customize image size
//gfx.DrawImage(watermarkImg, location.X, location.Y, 50, 50);

document.Save("image-watermark.pdf");

If you have additional questions about this, please directly reply.