ByteScout PDF SDK – C# – Set Invisible Text Over Image in PDF

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ByteScout PDF SDK – C# – Set Invisible Text Over Image in PDF

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ByteScout-PDF-SDK-C-sharp-Set-Invisible-Text-Over-Image-in-PDF.pdf

How to set invisible text over image in PDF in C# and ByteScout PDF SDK

The tutorial below will demonstrate how to set invisible text over image in PDF in C#

ByteScout tutorials are designed to explain the code for both C# beginners and advanced programmers. ByteScout PDF SDK: the component to help programmers in generating new pdf files, modifying and updating existing pdf documents or pdf forms. Provides support for auto-filling pdf forms, adding text with adjustable font, style, size, font family, new form fields, vector and raster drawings. It can set invisible text over image in PDF in C#.

This rich sample source code in C# for ByteScout PDF SDK includes the number of functions and options you should do calling the API to set invisible text over image in PDF. This C# sample code is all you need for your app. Just copy and paste the code, add references (if needs to) and you are all set! Code testing will allow the function to be tested and work properly with your data.

Our website provides trial version of ByteScout PDF SDK for free. It also includes documentation and source code samples.

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Program.cs

      using System.Diagnostics;
using Bytescout.PDF;

namespace InvisibleTextOverImage
{
    /// <summary>
    /// This example demonstrates how to create PDF document from scanned document image and add invisible text over it. 
    /// </summary>
    class Program
    {
        static void Main()
        {
            // Create new PDF document
            Document pdfDocument = new Document();
            pdfDocument.RegistrationName = "demo";
            pdfDocument.RegistrationKey = "demo";


            // Load image from file to System.Drawing.Image object (we need it to get the image resolution)
            System.Drawing.Image sysImage = System.Drawing.Image.FromFile(@".\scanned-invoice.png");
            // Compute image size in PDF units (Points)
            float widthInPoints = sysImage.Width / sysImage.HorizontalResolution * 72f;
            float heightInPoints = sysImage.Height / sysImage.VerticalResolution * 72f;

            // Create page of computed size
            Page page = new Page(widthInPoints, heightInPoints);
            // Add page to the document
            pdfDocument.Pages.Add(page);

            Canvas canvas = page.Canvas;

            // Create Bytescout.PDF.Image object from loaded image
            Image pdfImage = new Image(sysImage);
            // Draw the image
            canvas.DrawImage(pdfImage, 0, 0, widthInPoints, heightInPoints);

            // Dispose the System.Drawing.Image object to free resources
            sysImage.Dispose();

            // Create brush
            SolidBrush transparentBrush = new SolidBrush(new ColorGray(0));
            // ... and make it transparent
            transparentBrush.Opacity = 0;

            // Draw text with transparent brush
            Font font16 = new Font(StandardFonts.Helvetica, 16);
            canvas.DrawString("Your Company Name", font16, transparentBrush, 40, 40);
            // Draw another text
            Font font10 = new Font(StandardFonts.Helvetica, 10);
            canvas.DrawString("Your Address", font10, transparentBrush, 40, 80);

            
            // Save document to file
            pdfDocument.Save("result.pdf");

            // Cleanup 
            pdfDocument.Dispose();

            // Open result document in default associated application (for demo purpose)
            ProcessStartInfo processStartInfo = new ProcessStartInfo("result.pdf");
            processStartInfo.UseShellExecute = true;
            Process.Start(processStartInfo);
        }
    }
}