using System;
using System.Diagnostics;
using System.Drawing;
using System.Collections.Generic;
using Bytescout.Watermarking;
using Bytescout.Watermarking.Presets;

namespace Sample
{
class Program
{
static void Main(string[] args)
{
// Create Watermarker instance
Watermarker waterMarker = new Watermarker();

// Initialize library
waterMarker.InitLibrary("demo", "demo");

// Set input file name
string inputFilePath = "my_sample_image.jpg";
// Set output file title
string outputFilePath = "my_sample_output.jpg";

// Add image to apply watermarks to
waterMarker.AddInputFile(inputFilePath, outputFilePath);

// Create new watermark
TextFitsPageDiagonal preset = new TextFitsPageDiagonal();

// Set watermark text
preset.Text = "Bytescout Watermarking";

// Set watermark font
preset.Font = new WatermarkFont("Tahoma", FontStyle.Regular, FontSizeType.Points, 30);

// Set watermark text color
preset.TextColor = Color.Black;

// Set text transparency
preset.Transparency = 40;

// Set watermark orientation
preset.Orientation = DiagonalOrientation.FromTopLeftToBottomRight;

// Add watermark to watermarker
waterMarker.AddWatermark(preset);

// Set output directory
waterMarker.OutputOptions.OutputDirectory = ".";

// Set output format
waterMarker.OutputOptions.ImageFormat = OutputFormats.JPEG;

// Apply watermarks
waterMarker.Execute();

// open generated image file in default image viewer installed in Windows
Process.Start(outputFilePath);
}
}
}

Download source code: watermarkingsdk_text_fits_page_diagonal_preset_advanced.zip (240 KB)

You can also use EXIF macros to watermark images with their extended information. See this sample to view tutorial