Bytescout.Watermarking SDK is a native .NET library to mark image files (JPG, PNG, GIF, TIF and other) with text, stamps, annotations, logotypes, EXIF text macros within your .NET desktop or web-application.

Benefits:

Royalty-free distribution along with your product/application;
Made with 100% C# code for .NET (optional full source code licensing is available);
built-in set of ready-to-use customizable presets: Simple Text, Text Annotation, Logo Image,
Logo With Text, Text Fits Page, Vertical Text, FileName, DateTime stamp presets and other;
adjustable transparency for text and logo images;
customizable font settings, text location, rotation, margins and other;
supports batch watermarking of image files;
image resizing option (including batch resizing);
ability to add effects to pictures for better protection;
provides ability to process pictures using stream-to-stream operation (for Web applications);
provides support for EXIF and picture file information macros;
supports JPEG, TIFF (including CCITT b/w documents), GIF, PNG image formats as input and output;
12 months of free updates and 12 months of free tech support via e-mail (within 2 business days) are included.
Additional 12 months are available at 30% of regular price.