''' <summary>
''' Converts a PDF document to conformance with PDF/A-1b specification.
''' </summary>
''' <param name="pdfFilename">The filename of source PDF document.</param>
''' <param name="outputPdfFilename">The filename of output PDF document.</param>
Public Shared Sub ConvertDocumentToPdfA1b(pdfFilename As String, outputPdfFilename As String)
    ' determine that file must converted to the PDF/A-1b and saved back to the source file
    Dim sameFile As Boolean = pdfFilename.ToUpperInvariant() = outputPdfFilename.ToUpperInvariant()

    ' create the PDF/A-1b converter
    Dim converter As New Vintasoft.Imaging.Pdf.Processing.PdfA.PdfA1bConverter()
    converter.LzwFixupCompression = Vintasoft.Imaging.Pdf.PdfCompression.Zip
    ' converter.OutputIntentDestIccProfile = ...

    ' execute the conversion
    System.Console.WriteLine("Conversion...")
    Dim result As Vintasoft.Imaging.Processing.ConversionProfileResult = converter.Convert(pdfFilename, outputPdfFilename, New Vintasoft.Imaging.Processing.ProcessingState())

    ' if PDF document is converted successfully
    If result.IsSuccessful Then
        System.Console.WriteLine("Document converted to PDF/A-1b.")
    Else
        ' if PDF document is NOT converted
        If Not sameFile Then
            System.IO.File.Delete(outputPdfFilename)
        End If

        Throw result.CreateConversionException()
    End If
End Sub

/// <summary>
/// Converts a PDF document to conformance with PDF/A-1b specification.
/// </summary>
/// <param name="pdfFilename">The filename of source PDF document.</param>
/// <param name="outputPdfFilename">The filename of output PDF document.</param>
public static void ConvertDocumentToPdfA1b(string pdfFilename, string outputPdfFilename)
{
    // determine that file must converted to the PDF/A-1b and saved back to the source file
    bool sameFile = pdfFilename.ToUpperInvariant() == outputPdfFilename.ToUpperInvariant();
    
    // create the PDF/A-1b converter
    Vintasoft.Imaging.Pdf.Processing.PdfA.PdfA1bConverter converter = 
        new Vintasoft.Imaging.Pdf.Processing.PdfA.PdfA1bConverter();
    converter.LzwFixupCompression = Vintasoft.Imaging.Pdf.PdfCompression.Zip;
    // converter.OutputIntentDestIccProfile = ...
    
    // execute the conversion
    System.Console.WriteLine("Conversion...");
    Vintasoft.Imaging.Processing.ConversionProfileResult result = 
        converter.Convert(pdfFilename, outputPdfFilename, new Vintasoft.Imaging.Processing.ProcessingState());

    // if PDF document is converted successfully
    if (result.IsSuccessful)
    {
        System.Console.WriteLine("Document converted to PDF/A-1b.");
    }
    // if PDF document is NOT converted
    else
    {
        if (!sameFile)
            System.IO.File.Delete(outputPdfFilename);

        throw result.CreateConversionException();
    }
}