.NET API to Watermark Documents

Nuget

This .NET component offers read & write watermark support for the documents of 40+ file formats. Supports watermark search, customization & extraction as well.

Document Watermark Processing Features

Add text and image watermark to supported document formats.
Search and remove text and image watermarks.
Search watermarks in particular objects.
Apply a watermark to images inside a document.
Work with existing watermark objects.
Extract information of watermark objects in a document.
Perform PDF document rasterization.
Fetch document basic information.
Search watermarks by text formatting (font, color, etc.).
Set background image for charts in Excel and PowerPoint documents.
Work with PDF and email attachments.

Read & Write Watermark Formats

Microsoft Word: DOC, DOT, DOCX, DOCM, DOTX, DOTM, RTF
Microsoft Excel: XLSX, XLSM, XLTM, XLT, XLTX, XLS
Microsoft PowerPoint: PPTX, PPTM, PPSX, PPSM, POTX, POTM, PPT, PPS
Microsoft Visio: VSD, VDX, VSDX, VSTX, VSS, VSSX, VSDM, VSSM, VSTM, VTX, VSX
OpenOffice: ODT
Email: EML, EMLX, OFT, MSG
Fixed Layout: PDF
Image: BMP, GIF, JPG/JPEG/JPE, JP2, PNG, TIFF, WEBP

Platform Independence

GroupDocs.Watermark for .NET does not require any external software or third-party tool to be installed. GroupDocs.Watermark for .NET supports any 32-bit or 64-bit operating system where .NET or Mono framework is installed. The other details are as follows:

Microsoft Windows: Microsoft Windows Desktop (x86, x64) (XP & up), Microsoft Windows Server (x86, x64) (2000 & up)
Development Environments: Microsoft Visual Studio (2010 & up)
Supported Frameworks: GroupDocs.Conversion for .NET supports .NET frameworks.

Get Started

Are you ready to give GroupDocs.Watermark for .NET a try? Simply execute Install-Package GroupDocs.Watermark from Package Manager Console in Visual Studio to fetch & reference GroupDocs.Watermark assembly in your project. If you already have GroupDocs.Watermark for .Net and want to upgrade it, please execute Update-Package GroupDocs.Watermark to get the latest version.

Please check the GitHub Repository for other common usage scenarios.

Using C# to Add Watermark to All Images on a PDF Page

PdfLoadOptions loadOptions = new PdfLoadOptions();
// Constants.InDocumentPdf is an absolute or relative path to your document. Ex: @"C:\Docs\document.pdf"
using (Watermarker watermarker = new Watermarker(Constants.InDocumentPdf, loadOptions))
{
    // initialize image or text watermark
    TextWatermark watermark = new TextWatermark("Protected image", new Font("Arial", 8));
    watermark.HorizontalAlignment = HorizontalAlignment.Center;
    watermark.VerticalAlignment = VerticalAlignment.Center;
    watermark.RotateAngle = 45;
    watermark.SizingType = SizingType.ScaleToParentDimensions;
    watermark.ScaleFactor = 1;

    PdfContent pdfContent = watermarker.GetContent<PdfContent>();

    // get all images from the first page
    WatermarkableImageCollection images = pdfContent.Pages[0].FindImages();

    // add watermark to all found images
    foreach (WatermarkableImage image in images)
    {
        image.Add(watermark);
    }

    watermarker.Save(Constants.OutDocumentPdf);
}

Search Watermarks in PDF using Regular Expression via C# Code

// Constants.InDocumentPdf is an absolute or relative path to your document. Ex: @"C:\Docs\document.pdf"
using (Watermarker watermarker = new Watermarker(Constants.InDocumentPdf))
{
    Regex regex = new Regex(@"^Â© \d{4}$");

    // search by regular expression
    TextSearchCriteria textSearchCriteria = new TextSearchCriteria(regex);

    // find possible watermarks using regular expression
    PossibleWatermarkCollection possibleWatermarks = watermarker.Search(textSearchCriteria);

    Console.WriteLine("Found {0} possible watermark(s).", possibleWatermarks.Count);
}