使用C＃将pdf转换为图像-Ghostscript

Question

I need to convert pdf-files into images with a script in C# for Unity. Ghostscript shouldn't be installed on disk to do this. I tried to include the ghostscript .dll and use it with a wrapper which uses the following functions:

gsapi_new_instance
gsapi_init_with_args
gsapi_exit
gsapi_delete_instance

However, if I use the commands -sDEVICE=png16m -sOutputFile=outputpath.png inputpath.pdf as arguments, it is not working. The first page of the pdf file is created but the others are not. I used "-%d" in the outputpath, but it's not working either. eg C:\\Example-%d.png

I am using Ghostscript version 9.16, Unity version 5.2.0f3 and Visual Studio 2015.

Can please anyone tell me, why the first image file is created and the others are not? Is there any simple alternative for using ghostscript to create multiple images from a pdf by using C#?

Answer 1

Have you tried Magick.Net ?

It's a very popular .NET wrapper for the ImageMagick library (It uses Ghostscript under the hood for pdfs)

Answer 2

First install NuGet Install-Package GhostScriptSharp . Then you could do something like this:

/// <summary>
/// Convertetion PDF to image.
/// </summary>
/// <param name="Path">Path to file for convertetion</param>
/// <param name="PDFfile">Book name on HDD</param>
/// <param name="Devise">Select one of the formats, jpg</param>
/// <param name="PageFormat">Select one of page formats, like A4</param>
/// <param name="qualityX"> Select quality, 200X200 ~ 1200X1900</param>
/// <param name="qualityY">Select quality, 200X200 ~ 1200X1900</param>
    public void CreatPDF(string Path, string PDFfile, GhostscriptSharp.Settings.GhostscriptDevices Devise,
GhostscriptSharp.Settings.GhostscriptPageSizes PageFormat, int qualityX, int qualityY)
    {
        GhostscriptSharp.GhostscriptSettings SettingsForConvert = new GhostscriptSharp.GhostscriptSettings();

        SettingsForConvert.Device = Devise;

        GhostscriptSharp.Settings.GhostscriptPageSize pageSize = new GhostscriptSharp.Settings.GhostscriptPageSize();
        pageSize.Native = PageFormat;
        SettingsForConvert.Size = pageSize;

        SettingsForConvert.Resolution = new System.Drawing.Size(qualityX, qualityY);

        GhostscriptSharp.GhostscriptWrapper.GenerateOutput(Path, @"C:\" + PDFfile + "\\" + PDFfile + "_" + "%d.jpg", SettingsForConvert); // here you could set path and name for out put file.
    }

Answer 3

Many thanks to KenS and all the others.

My problem was that I defined -dNOPAUSE as my first argument. However, the first argument shouldn't be defined for ghostscript. It is not realized from ghostscript, so that's why I got only the first page. Thanks to KenS suggestion with -dNOPAUSE, I was able to find the error.

I hope this helps others, too.