PdfRasterizer.cs

using System.Drawing;
using System.IO;
using Ghostscript.NET;
using Ghostscript.NET.Rasterizer;
using System;
using System.Reflection;

namespace ImageProcessor.Plugins.Pdf
{
    internal class PdfRasterizer
    {
        private readonly int _desiredXDpi;
        private readonly int _desiredYDpi;
        private readonly GhostscriptVersionInfo _lastInstalledVersion;
        private readonly GhostscriptRasterizer _rasterizer;

        public PdfRasterizer(int xDpi = 96, int yDpi = 96)
        {
            _desiredXDpi = xDpi;
            _desiredYDpi = yDpi;

            var dllPath = Path.Combine(GetBinPath(), Environment.Is64BitProcess ? "gsdll64.dll" : "gsdll32.dll");

            if (File.Exists(dllPath))
            {
                // use DLL in bin folder
                _lastInstalledVersion = new GhostscriptVersionInfo(new System.Version(0, 0, 0), dllPath, string.Empty, GhostscriptLicense.GPL | GhostscriptLicense.AFPL);
            }
            else
            {
                // try to use installed DLL
                _lastInstalledVersion = GhostscriptVersionInfo.GetLastInstalledVersion(GhostscriptLicense.GPL | GhostscriptLicense.AFPL, GhostscriptLicense.GPL);
            }

            _rasterizer = new GhostscriptRasterizer();
        }

        public Image Rasterize(string pdfUri, int pageNumber = 1)
        {
            _rasterizer.Open(pdfUri, _lastInstalledVersion, true);

            var img = _rasterizer.GetPage(_desiredXDpi, _desiredYDpi, pageNumber);

            _rasterizer.Close();
            return img;
        }

        public Image Rasterize(Stream pdfStream, int pageNumber = 1)
        {
            _rasterizer.Open(pdfStream, _lastInstalledVersion, true);

            var img = _rasterizer.GetPage(_desiredXDpi, _desiredYDpi, pageNumber);

            _rasterizer.Close();
            return img;
        }

        private string GetBinPath()
        {
            string codeBase = Assembly.GetExecutingAssembly().CodeBase;

            UriBuilder uri = new UriBuilder(codeBase);

            string path = Uri.UnescapeDataString(uri.Path);

            return Path.GetDirectoryName(path);
        }
    }
}