Set Default Font Name

In this tutorial, we will show you how to set the default font name in a PDF file using Aspose.PDF for .NET. Sometimes when you extract images from a PDF file, you may encounter missing font issues. By specifying a default font name, you can ensure that extracted text will be displayed correctly. Follow the steps below to set the default font name in a PDF file.

Prerequisites

Before you begin, make sure you meet the following prerequisites:

• Basic knowledge of the C# programming language.
• Aspose.PDF library for .NET installed on your system.
• A development environment such as Visual Studio.

Step 1: Loading the PDF document

The first step is to load the PDF document into a Document object. Use the following code:

// Path to the documents directory.
string dataDir = "YOUR DOCUMENTS DIRECTORY";

using (Document pdfDocument = new Document(dataDir + "input.pdf"))
{
     // Code to add
}

Be sure to replace "YOUR DOCUMENTS DIRECTORY" with the actual directory where your PDF file is located.

Step 2: Set default font name

Next, we’ll set the default font name using the DefaultFontName option of the RenderingOptions object. Use the following code:

using (Document pdfDocument = new Document(dataDir + "input.pdf"))
{
     using (FileStream imageStream = new FileStream(dataDir + "SetDefaultFontName.png", FileMode.Create))
     {
         Resolution resolution = new Resolution(300);
         PngDevice pngDevice = new PngDevice(resolution);
         RenderingOptions ro = new RenderingOptions();
         ro.DefaultFontName = "Arial";
         pngDevice.RenderingOptions = ro;
        
         // Code to add
     }
}

Be sure to replace "Arial" with the desired font name.

Step 3: Image Extraction

Next, we will extract the image from the specified page of the PDF document. Use the following code:

pngDevice.Process(pdfDocument.Pages[1], imageStream);

Be sure to specify the correct page number in pdfDocument.Pages[1].

Example source code for Set Default Font Name using Aspose.PDF for .NET

// The path to the documents directory.
string dataDir = "YOUR DOCUMENT DIRECTORY";

using (Document pdfDocument = new Document(dataDir + "input.pdf"))
{
	using (FileStream imageStream = new FileStream(dataDir + "SetDefaultFontName.png", FileMode.Create))
	{
		Resolution resolution = new Resolution(300);
		PngDevice pngDevice = new PngDevice(resolution);
		RenderingOptions ro = new RenderingOptions();
		ro.DefaultFontName = "Arial";
		pngDevice.RenderingOptions = ro;
		pngDevice.Process(pdfDocument.Pages[1], imageStream);
	}
}

Conclusion

In this tutorial, we learned how to set the default font name in a PDF file using Aspose.PDF for .NET. By specifying a default font name, you can ensure that extracted text will be displayed correctly. Use this method to resolve missing font issues when extracting images from PDF files.

FAQ’s

Q: What is Aspose.PDF for .NET?

A: Aspose.PDF for .NET is a powerful library that enables developers to work with PDF documents in C# applications. It offers various functionalities, including setting the default font name in a PDF file.

Q: Why would I need to set the default font name in a PDF file?

A: Setting the default font name is useful when extracting text from a PDF document. If the PDF contains text with fonts that are not available on the extraction machine, specifying a default font name ensures correct text display.

Q: How can I load a PDF document and set the default font name using Aspose.PDF for .NET?

A: To load a PDF document and set the default font name, you can use the Document class to load the PDF file and the RenderingOptions.DefaultFontName property to specify the desired default font name.

Q: Can I choose any font as the default font name?

A:Yes, you can choose any font that is available on the extraction machine as the default font name. Use a font that closely matches the missing fonts in the original PDF to ensure accurate text rendering.

Q: Is setting the default font name a permanent change to the PDF file?

A: No, setting the default font name using Aspose.PDF for .NET is a temporary change made during text extraction. It does not modify the original PDF file.