Convert PDF to Image without using Ghostscript DLL

Question

Is there any way, I can convert HTML Document (file not URL) to Image, or PDF to image?

I am able to do the above using Ghostscript DLL , Is there any other way , I can do it, without using the Ghostscript DLL?

I am developing a C# Windows Application.

Answer 1

the best and free nuget package that you can save every page of your Pdf to png and with custom resilution Docnet.core this can be use in the .net core project.

they have github and nice examples but here i want to add my code for reading en pdf with more that one page

        string webRootPath = _hostingEnvironment.WebRootPath;
        string fullPath = webRootPath + "/uploads/user-manual/file.pdf";
        string fullPaths = webRootPath + "/uploads/user-manual";

        using (var library = DocLib.Instance)
        {
            using (var docReader = library.GetDocReader(fullPath, 1080, 1920))
            {
                for (int i = 1; i < docReader.GetPageCount(); i++)
                {
                    using (var pageReader = docReader.GetPageReader(i))
                    {
                        var bytes = EmailTemplates.GetModifiedImage(pageReader);

                        System.IO.File.WriteAllBytes(fullPaths+"/page_image_" +i+".png", bytes);
                    }
                }

            }
        }

Other functions you can find in thier github repo.

Answer 2

Use LibPdf, for PDF to Image conversion

LibPdf library converts converts PDF file to an image. Supported image formats are PNG and BMP, but you can easily add more.

Usage example:

using (FileStream file = File.OpenRead(@"..\path\to\pdf\file.pdf")) // in file
{
    var bytes = new byte[file.Length];
    file.Read(bytes, 0, bytes.Length);
    using (var pdf = new LibPdf(bytes))
    {
        byte[] pngBytes = pdf.GetImage(0,ImageType.PNG); // image type
        using (var outFile = File.Create(@"..\path\to\pdf\file.png")) // out file
        {
            outFile.Write(pngBytes, 0, pngBytes.Length);
        }
    }
}

ImageMagick, you should also look at this freely available and powerful tool. It's capable of doing what you want and also provides some .NET bindings (as well as bindings to several other languages).

In its simplest form, it's just like writing a command

convert file.pdf imagefile.png

Answer 3

Try Freeware.Pdf2Png, check below url:

PDF to PNG converter.

byte[] png = Freeware.Pdf2Png.Convert(pdf, 1);

https://www.nuget.org/packages/Freeware.Pdf2Png/1.0.1?_src=template

In the about info, It said MIT license, I check it on March 22, 2022. But as said Mitya, please double check.

Answer 4

Using docnet, based in this example on github, I did this, very simple and functional :

pdf used in this example.

//...
using Docnet.Core;
using System.IO;
using Docnet.Core.Models;
using System.Drawing;
using System.Drawing.Imaging;
using System.Runtime.InteropServices;

//paths
string pathPdf = @"C:\pathToPdfFile\lorem-ipsum.pdf";
string finalPathWithFileName = @"C:\pathToFinalImageFile\finalFile.png";

//using docnet
using (var docReader = DocLib.Instance.GetDocReader(pathPdf, new PageDimensions(1080, 1920)))
{
    //open pdf file
    using (var pageReader = docReader.GetPageReader(0))
    {
        var rawBytes = pageReader.GetImage();
        var width = pageReader.GetPageWidth();
        var height = pageReader.GetPageHeight();
        var characters = pageReader.GetCharacters();

        //using bitmap to create a png image
        using (var bmp = new Bitmap(width, height, PixelFormat.Format32bppArgb))
        {
            AddBytes(bmp, rawBytes);

            using (var stream = new MemoryStream())
            {
                //saving and exporting
                bmp.Save(stream, ImageFormat.Png);
                File.WriteAllBytes(finalPathWithFileName, stream.ToArray());
            };
        };
    };
};

//extra methods
private static void AddBytes(Bitmap bmp, byte[] rawBytes)
{
    var rect = new Rectangle(0, 0, bmp.Width, bmp.Height);

    var bmpData = bmp.LockBits(rect, ImageLockMode.WriteOnly, bmp.PixelFormat);
    var pNative = bmpData.Scan0;

    Marshal.Copy(rawBytes, 0, pNative, rawBytes.Length);
    bmp.UnlockBits(bmpData);
}

Answer 5

You can use below any one library for PDF to Image conversion

Use Aspose.pdf link below: http://www.aspose.com/docs/display/pdfnet/Convert+all+PDF+pages+to+JPEG+Images

code sample:

Aspose.Pdf.Document pdfDocument = new Aspose.Pdf.Document(MyPdfPath));
using (FileStream imageStream = new FileStream(MyOutputImage.png, FileMode.Create))
{
     Resolution resolution = new Resolution(300);
    PngDevice pngDevice = new PngDevice(resolution);
    pngDevice.Process(pdfDocument.Pages[PageNo], MyOutputImage);
    imageStream.Close();
}

Use Bytescout PDF Renderer link below: http://bytescout.com/products/developer/pdfrenderersdk/convert-pdf-to-png-basic-examples

code sample :

MemoryStream ImageStream = new MemoryStream();
RasterRenderer renderer = new RasterRenderer();
renderer.RegistrationName = "demo";
renderer.RegistrationKey = "demo";
// Load PDF document.
renderer.LoadDocumentFromFile(FilePath);
for (int i = 0; i < renderer.GetPageCount(); i++)
{
    // Render first page of the document to PNG image file.
    renderer.RenderPageToStream(i, RasterOutputFormat.PNG, ImageStream);
}
Image im = Image.FromStream(ImageStream);
im.Save("MyOutputImage.png");
ImageStream.Close();

Answer 6

Spire.PDF library can be used for PDF to Image conversion, such as PDF to PNG, JPG, EMF and TIFF etc.

The following is the code example shows how to convert PDF to PNG:

 //Load a PDF
 PdfDocument doc = new PdfDocument();
 doc.LoadFromFile("PdfFilePath");

 //Save to PNG images
 for (int i = 0; i < doc.Pages.Count; i++)
 {
     String fileName = String.Format("ToImage-img-{0}.png", i);
     using (Image image = doc.SaveAsImage(i,300,300))
     {
         image.Save(fileName, System.Drawing.Imaging.ImageFormat.Png);
     }
 }

 doc.Close();

More conversion examples can be found in the library's documentation. It also provides a free community edition but with some limitations.

Answer 7

Freeware.Pdf2Png worked great for my needs. It does not only convert to Png, you can save to the image format of your choice.

In MS Visual Studio run this in your Package Manager console PM> NuGet\Install-Package Freeware.Pdf2Png -Version 1.0.1, or just add via the NuGet Package Manager GUI, search for Freeware.Pdf2Png and it should come up.

Once the reference is added to your project, code similar to this should do what you need to convert a PDF to an Image.

using (FileStream fs = new FileStream(FullFilePath, FileMode.Open))
{
    byte[] buff = Freeware.Pdf2Png.Convert(fs, 1);
    MemoryStream ms = new MemoryStream(buff);
    Image img = Image.FromStream(ms);
    img.Save(TiffFilePath, System.Drawing.Imaging.ImageFormat.Tiff);
}

FullFilePath - a string that is the Full File Path to the PDF to be converted.

TiffFilePath - a string that is the Full File Path of the newly created Image that you would like to save.

Unfortunately I was not able to find any c# code or proper algorithm to do this conversion without a 3rd party DLL. If any of you have good information for that please do share it!

Answer 8

While using Ghostscript with ImageMagick is a potential option, it is incredibly slow, every page would take around 5 or more seconds. DocNet is a much better option to convert pdf to images. The following code would convert all pages in a pdf file into Images, and do that fast.

 public void SavePDFtoJPGDocnet(string fileName)
    {
        string FilePath = @"C:\SampleFileFolder\doc.pdf";
        string DestinationFolder = @"C:\SampleFileFolder\";

        IDocLib DocNet = DocLib.Instance;

        //you are specifying the max resolution of image on any side, actual resolution will be limited by longer side, 
        //preserving the aspect ratio
        var docReader = DocNet.GetDocReader(
        FilePath,
        new PageDimensions(1440, 2560));


        for (int i = 0; i < docReader.GetPageCount(); i++)
        {
            using (var pageReader = docReader.GetPageReader(i))
            {
                var rawBytes = pageReader.GetImage();

                var width = pageReader.GetPageWidth();
                var height = pageReader.GetPageHeight();

                var characters = pageReader.GetCharacters();

                var bmp = new Bitmap(width, height, PixelFormat.Format32bppArgb);

                DocnetClass.AddBytes(bmp, rawBytes);
                //DocnetClass.DrawRectangles(bmp, characters);

                var stream = new MemoryStream();

                bmp.Save(stream, ImageFormat.Png);

                File.WriteAllBytes(DestinationFolder + "/page_image_" + i + ".png", stream.ToArray());

            }
        }

           
        

       
    }

Answer 9

In case someone wants to use Ghostscript.NET.

Ghostscript.NET - (written in C#) is the most completed managed wrapper library around the Ghostscript library (32-bit & 64-bit), an interpreter for the PostScript language, PDF.

It is dependent on executable file you have to install on your machine. Here is a link from where you can see and download the latest version of the exe.

https://www.ghostscript.com/download/gsdnld.html

P.S. I had some troubles with the latest version 9.50 not being able to count the pages.

I prefer using the 9.26 version.

https://github.com/ArtifexSoftware/ghostpdl-downloads/releases/download/gs926/gs926aw32.exe

https://github.com/ArtifexSoftware/ghostpdl-downloads/releases/download/gs926/gs926aw64.exe

Next step is to find and install Ghostscript.NET from Nuget. I download the PDF from CDN url and use the MemoryStream to open and process the PDF file. Here is a sample code:

using (WebClient myWebClient = new WebClient())
            {
                using (GhostscriptRasterizer rasterizer = new GhostscriptRasterizer())
                {
                    /* custom switches can be added before the file is opened

                    rasterizer.CustomSwitches.Add("-dPrinted");

                    */
                    byte[] buffer = myWebClient.DownloadData(pdfUrl);
                    using (var ms = new MemoryStream(buffer))
                    {
                        rasterizer.Open(ms);
                        var image = rasterizer.GetPage(0, 0, 1);

                        var imageURL = "MyCDNpath/Images/" + filename + ".png";
                        _ = UploadFileToS3(image, imageURL);
                    }
                }
            }

You can also use it with temporary FileStream. Here is another example. Note that the File is temporary and has DeleteOnClose mark.

using (WebClient myWebClient = new WebClient())
            {
                using (GhostscriptRasterizer rasterizer = new GhostscriptRasterizer())
                {
                    /* custom switches can be added before the file is opened

                    rasterizer.CustomSwitches.Add("-dPrinted");

                    */
                    byte[] buffer = myWebClient.DownloadData(pdfUrl);

                    int bufferSize = 4096;

                    using (var fileStream = System.IO.File.Create("TempPDFolder/" + pdfName, bufferSize, System.IO.FileOptions.DeleteOnClose))
                    {
                        // now use that fileStream to save the pdf stream
                        fileStream.Write(buffer, 0, buffer.Length);
                        rasterizer.Open(fileStream);
                        var image = rasterizer.GetPage(0, 0, 1);

                        var imageURL = "MyCDNpath/Images/" + filename + ".png";

                        _ = UploadFileToS3(image, imageURL);
                    }
                }
            }

Hope it will help someone struggling to get high quality images from pdf for free.