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C#/VB.NET: Convert PDF to Images (JPG, PNG, BMP)

2023-06-12 07:27:00 Written by  daisy zhang
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PDF files have the advantage of being highly interactive and easy to transfer, but in certain cases, it is also necessary to convert PDF to images for embedding in web pages or displaying on some platforms that do not support PDF format. In this article, you will learn how to convert PDF to JPG, PNG or BMP image formats in C# and VB.NET using Spire.PDF for .NET.

Install Spire.PDF for .NET

To begin with, you need to add the DLL files included in the Spire.PDF for.NET package as references in your .NET project. The DLL files can be either downloaded from this link or installed via NuGet.

PM> Install-Package Spire.PDF 

Convert a Specific PDF Page to an Image in C# and VB.NET

Spire.PDF for .NET offers the PdfDocument.SaveAsImage() method to convert a particular page in PDF to an image. Then, you can save the image as a JPEG, PNG, BMP, EMF, GIF or WMF file. The following are the detailed steps.

  • Create a Document instance.
  • Load a sample PDF document using PdfDocument.LoadFromFile() method.
  • Convert a specific page to an image and set the image Dpi using PdfDocument.SaveAsImage(int pageIndex, PdfImageType type, int dpiX, int dpiY) method.
  • Save the image as a PNG, JPG or BMP file using Image.Save(string filename, ImageFormat format) method.
  • C#
  • VB.NET
using Spire.Pdf;
using Spire.Pdf.Graphics;
using System.Drawing;
using System.Drawing.Imaging;

namespace PDFtoImage
{
    class Program
    {
        static void Main(string[] args)
        {
            //Create a PdfDocument instance
            PdfDocument pdf = new PdfDocument();

            //Load a sample PDF document
            pdf.LoadFromFile("E:\\Files\\input.pdf");

            //Convert the first page to an image and set the image Dpi
            Image image = pdf.SaveAsImage(0, PdfImageType.Bitmap, 500, 500);

            //Save the image as a JPG file
            image.Save("ToJPG.jpg", ImageFormat.Jpeg);

            //Save the image as a PNG file
            //image.Save("ToPNG.png", ImageFormat.Png);

            //Save the image as a BMP file
            //image.Save("ToBMP.bmp", ImageFormat.Bmp);
        }
    }
}

C#/VB.NET: Convert PDF to Images (JPG, PNG, BMP)

Convert an Entire PDF Document to Multiple Images in C# and VB.NET

If you want to convert the whole PDF document into multiple individual images, you can loop through all the pages in the PDF and then save them as JPG, PNG or BMP images. The following are the detailed steps.

  • Create a PdfDocument instance.
  • Load a sample PDF document using PdfDocument.LoadFromFile() method.
  • Loop through all pages of the document and set the image Dpi when converting them to images using PdfDocument.SaveAsImage(int pageIndex, PdfImageType type, int dpiX, int dpiY) method.
  • Save images as PNG files using Image.Save() method.
  • C#
  • VB.NET
using Spire.Pdf;
using Spire.Pdf.Graphics;
using System;
using System.Drawing;
using System.Drawing.Imaging;

namespace PDFtoImage
{
    class Program
    {
        static void Main(string[] args)
        {
            //Create a PdfDocument instance
            PdfDocument pdf = new PdfDocument();

            //Load a sample PDF document
            pdf.LoadFromFile("input.pdf");

            //Loop through each page in the PDF
            for (int i = 0; i < pdf.Pages.Count; i++)
            {
                //Convert all pages to images and set the image Dpi
                Image image = pdf.SaveAsImage(i, PdfImageType.Bitmap, 500, 500);

                //Save images as PNG format to a specified folder 
                String file = String.Format("Image\\ToImage-{0}.png", i);
                image.Save(file, ImageFormat.Png);
              
            }
        }
    }
}

C#/VB.NET: Convert PDF to Images (JPG, PNG, BMP)

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Last modified on Monday, 12 June 2023 01:34