Cómo convertir PDF a Texto

public static class Function1
    {
        [FunctionName("Function1")]
        public static async Task Run(
            [HttpTrigger(AuthorizationLevel.Anonymous, "get", "post", Route = null)] HttpRequest req,
            ILogger log)
        {
            StringBuilder sbLogs = new StringBuilder();
            sbLogs.AppendLine("started...");
            try
            {
                ProcessStartInfo startInfo = new ProcessStartInfo();
                startInfo.CreateNoWindow = true;
                startInfo.UseShellExecute = false;
                var assemblyDirectoryPath = Path.GetDirectoryName(Assembly.GetExecutingAssembly().Location);
                assemblyDirectoryPath = assemblyDirectoryPath.Substring(0, assemblyDirectoryPath.Length - 4);

                var executablePath = $@"{assemblyDirectoryPath}\Converter\PDFConverterX.exe";
                sbLogs.AppendLine(executablePath + "...");
                var msgPath = $@"{assemblyDirectoryPath}\MSG\MSG.pdf";
                var outPath = Path.GetTempFileName() + ".tiff";
                startInfo.FileName = executablePath;

                if (File.Exists(outPath))
                {
                    File.Delete(outPath);
                }

                if (File.Exists(executablePath) && File.Exists(msgPath))
                {
                    sbLogs.AppendLine("files exists...");
                }
                else
                    sbLogs.AppendLine("EXE & MSG files NOT exists...");
                startInfo.WindowStyle = ProcessWindowStyle.Hidden;
                startInfo.Arguments = $"{msgPath} {outPath}";
                using (Process exeProcess = Process.Start(startInfo))
                {
                    sbLogs.AppendLine($"wait...{DateTime.Now.ToString()}");
                    exeProcess.WaitForExit();
                    sbLogs.AppendLine($"complete...{DateTime.Now.ToString()}");
                }

                int sleepCounter = 10;

                while(!File.Exists(outPath) && sleepCounter > 0)
                {
                    System.Threading.Thread.Sleep(1000);
                    sbLogs.AppendLine("sleep...");
                    sleepCounter--;
                }
                if (File.Exists(outPath))
                    sbLogs.AppendLine("Conversion complete successfully.");
            }
            catch (Exception ex)
            {
                sbLogs.AppendLine(ex.ToString());
            }

            return new OkObjectResult(sbLogs);
        }
    }

#include <windows.h>
static const CLSID CLSID_PDFConverterX =
  {0x6B411E7E, 0x9503,0x4793,{0xA2, 0x87, 0x1F, 0x3B, 0xA8, 0x78, 0xB9, 0x1C}};
static const IID IID_IPDFConverterX =
  {0xEF633BED, 0xC414,0x49B0,{0x91, 0xFB, 0xC3, 0x9C, 0x3F, 0xE0, 0x08, 0x0D}};

#undef INTERFACE
#define INTERFACE IPDFConverterX
DECLARE_INTERFACE_(IPDFConverterX, IDispatch)
{
    STDMETHOD(QueryInterface)(THIS_ REFIID, PVOID*) PURE;
    STDMETHOD(Convert)(THIS_ LPCTSTR, LPCTSTR, LPCTSTR) PURE;
    STDMETHOD(About)(THIS) PURE;
    //const SourceFile: WideString; const DestFile: WideString; const Params: WideString; safecall;
};

typedef HRESULT (__stdcall *hDllGetClassObjectFunc) (REFCLSID, REFIID, void **);

int main () {
  HRESULT hr;
  if (CoInitialize(NULL)) {
    printf ("Error en CoInitialize.");
    return -1;
  }

  LPCTSTR lpFileName = "PDFConverter.dll";
  HMODULE hModule;
  hModule = LoadLibrary (lpFileName);
  printf ("hModule: %d\n", hModule);
  if (hModule == 0) {
    printf ("Error en LoadLibrary.");
    return -1;
  }

  hDllGetClassObjectFunc hDllGetClassObject = NULL;
  hDllGetClassObject = (hDllGetClassObjectFunc) GetProcAddress (hModule, "DllGetClassObject");
  if (hDllGetClassObject == 0) {
    printf ("Error en GetProcAddress.");
    return -1;
  }
  IClassFactory *pCF = NULL;
  hr = hDllGetClassObject (&CLSID_PDFConverterX, &IID_IClassFactory, (void **)&pCF);
  /* No se puede cargar con ID diferente */
  printf ("hr hDllGetClassObject: %d\n", hr);
  if (!SUCCEEDED (hr)) {
    printf ("Error en hDllGetClassObject.");
    return -1;
  }
  IPDFConverterX *pIN;
  hr = pCF->lpVtbl->CreateInstance (pCF, 0, &IID_IPDFConverterX, (void **)&pIN);
  printf ("hr CreateInstance: %d\n", hr);
  if (!SUCCEEDED (hr)) {
    printf ("Error en hDllGetClassObject.");
    return -1;
  }
  hr = pCF->lpVtbl->Release (pCF);
  printf ("hr Release: %d\n", hr);
  if (!SUCCEEDED (hr)) {
    printf ("Error en Release.");
    return -1;
  }
  hr = pIN->lpVtbl->About (pIN);
  printf ("hr About: %d\n", hr);
  if (!SUCCEEDED (hr)) {
    printf ("Error en About.");
    return -1;
  }
  hr = pIN->lpVtbl->Convert (pIN, "test.pdf", "test.html","-cHTML");
  printf ("hr Convert: %d\n", hr);
  if (!SUCCEEDED (hr)) {
    printf ("Error en Convert.");
    return -1;
  }

  return 0;
}

dim C
Set C=CreateObject("PDFConverter.PDFConverterX")
C.Convert "c:\source.PDF", "c:\dest.HTML", "-cHTML -log c:\pdf.log"
set C = nothing

dim C
Set C=CreateObject("PDFConverter.PDFConverterX")
Response.Clear
Response.AddHeader "Content-Type", "binary/octet-stream"
Rresponse.AddHeader "Content-Disposition", "attachment; filename=test.TIFF"
Response.BinaryWrite c.ConvertToStream("C:\www\ASP\Source.PDF", "C:\www\ASP", "-cTIFF  -log c:\PDF.log")
set C = nothing

$src="C:\\test.pdf";
$dest="C:\\test.tiff";
if (file_exists($dest)) unlink($dest);
$c= new COM("PDFConverter.PDFConverterX");
$c->convert($src,$dest, "-c TIFF -log c:\doc.log");
if (file_exists($dest)) echo "OK"; else echo "fail:".$c->ErrorMessage;

require 'win32ole'
c = WIN32OLE.new('PDFConverter.PDFConverterX')

src="C:\\test\\test.pdf";
dest="C:\\test\\test.tiff";

c.convert(src,dest, "-c TIFF -log c:\\test\\PDF.log");

if not File.exist?(dest)
  puts c.ErrorMessage
end

import win32com.client
import os.path

c = win32com.client.Dispatch("PDFConverter.PDFConverterX")

src="C:\\test\\test.pdf";
dest="C:\\test\\test.tiff";

c.convert(src, dest, "-c TIFF -log c:\\test\\PDF.log");

if not os.path.exists(file_path):
  print(c.ErrorMessage)

uses Dialogs, Vcl.OleAuto;

var
  c: OleVariant;
begin
  c:=CreateOleObject('PDFConverter.PDFConverterX');
  C.Convert('c:\test\source.pdf', 'c:\test\dest.tiff', '-c TIFF -log c:\test\PDF.log');
  IF c.ErrorMessage<> Then
    ShowMessage(c.ErrorMessage);
end;

var c = new ActiveXObject("PDFConverter.PDFConverterX");
c.Convert("C:\\test\\source.pdf", "C:\\test\\dest.tiff", "-c TIFF");
if (c.ErrorMessage!="")
  alert(c.ErrorMessage)

use Win32::OLE;

my $src="C:\\test\\test.pdf";
my $dest="C:\\test\\test.tiff";

my $c = CreateObject Win32::OLE 'PDFConverter.PDFConverterX';
$c->convert($src,$dest, "-c TIFF  -log c:\\test\\PDF.log");
print $c->ErrorMessage if -e $dest;