class ScanAndConvertToSearchablePdfDcoument
{
    /// <summary>
    /// Acquires image from scanner,
    /// recognizes text on images and
    /// saves the result as a searchable PDF document.
    /// </summary>
    /// <remarks>
    /// VintaSoft Twain .NET SDK (Vintasoft.Twain.dll),
    /// VintaSoft Imaging .NET SDK (Standard) (Vintasoft.Imaging.dll),
    /// VintaSoft Document Cleanup .NET Plug-in (Vintasoft.Imaging.DocCleanup.dll),
    /// VintaSoft OCR .NET Plug-in (Vintasoft.Imaging.Ocr.dll, Vintasoft.Imaging.Ocr.Tesseract.dll),
    /// VintaSoft PDF .NET Plug-in (Vintasoft.Imaging.Pdf.dll, Vintasoft.Imaging.Pdf.Ocr.dll) and
    /// and VintaSoft PDF .NET Plug-in (Writer) (Vintasoft.Pdf.dll) are necessary
    /// for executing this sample.
    /// </remarks>
    public static void ScanImagesAndSaveAsSearchablePdfDocument(
        Vintasoft.Imaging.Ocr.OcrLanguage language,
        string outputPdfFilename)
    {
        System.Console.WriteLine("Create TWAIN device manager...");
        using (Vintasoft.Twain.DeviceManager deviceManager = 
            new Vintasoft.Twain.DeviceManager())
        {
            // create PDF document
            using (Vintasoft.Imaging.Pdf.PdfDocument pdfDocument = 
                new Vintasoft.Imaging.Pdf.PdfDocument(outputPdfFilename, Vintasoft.Imaging.Pdf.PdfFormat.Pdf_14))
            {
                // create PDF document builder
                Vintasoft.Imaging.Pdf.Ocr.PdfDocumentBuilder documentBuilder = 
                    new Vintasoft.Imaging.Pdf.Ocr.PdfDocumentBuilder(pdfDocument);
                documentBuilder.ImageCompression = Vintasoft.Imaging.Pdf.PdfCompression.Auto;
                documentBuilder.PageCreationMode = Vintasoft.Imaging.Pdf.Ocr.PdfPageCreationMode.ImageOverText;

                System.Console.WriteLine("Create Tesseract OCR engine...");
                using (Vintasoft.Imaging.Ocr.Tesseract.TesseractOcr tesseractOcr = 
                    new Vintasoft.Imaging.Ocr.Tesseract.TesseractOcr())
                {
                    // create OCR engine manager
                    Vintasoft.Imaging.Ocr.OcrEngineManager engineManager =
                        new Vintasoft.Imaging.Ocr.OcrEngineManager(tesseractOcr);

                    Vintasoft.Imaging.Ocr.OcrEngineSettings settings = 
                        new Vintasoft.Imaging.Ocr.OcrEngineSettings(language);

                    System.Console.WriteLine("Open TWAIN device manager...");
                    deviceManager.Open();

                    Vintasoft.Twain.Device device = deviceManager.DefaultDevice;

                    Vintasoft.Twain.AcquireModalState acquireState;
                    do
                    {
                        System.Console.WriteLine("Acquire image from scanner...");
                        acquireState = device.AcquireModal();
                        if (acquireState == Vintasoft.Twain.AcquireModalState.ImageAcquired)
                        {
                            // create VintasoftImage
                            using (Vintasoft.Imaging.VintasoftImage image =
                                Vintasoft.Imaging.VintasoftImageGdiExtensions.Create(device.AcquiredImage.GetAsBitmap(), true))
                            {
                                // preprocess image
                                // BorderClear, Despeckle, Deskew, Segmentation
                                System.Console.WriteLine("Preprocess the image...");
                                Vintasoft.Imaging.ImageProcessing.Document.OcrPreprocessingCommand preprocessing =
                                    new Vintasoft.Imaging.ImageProcessing.Document.OcrPreprocessingCommand();
                                preprocessing.Binarization = null;
                                preprocessing.ExecuteInPlace(image);

                                // recognize image
                                System.Console.WriteLine("Recognize the image...");
                                Vintasoft.Imaging.Ocr.Results.OcrPage page = engineManager.Recognize(image, settings,
                                    preprocessing.SegmentationTextRegions);

                                // add page to PDF document
                                System.Console.WriteLine("Add page to PDF document...");
                                documentBuilder.AddPage(image, page);
                            }

                            // dispose the acquired image
                            device.AcquiredImage.Dispose();
                        }
                    }
                    while (acquireState != Vintasoft.Twain.AcquireModalState.None);

                    System.Console.WriteLine("Save changes in PDF document...");
                    pdfDocument.SaveChanges();
                }
            }
        }
    }
}

Class ScanAndConvertToSearchablePdfDcoument
    ''' <summary>
    ''' Acquires image from scanner,
    ''' recognizes text on images and
    ''' saves the result as a searchable PDF document.
    ''' </summary>
    ''' <remarks>
    ''' VintaSoft Twain .NET SDK (Vintasoft.Twain.dll),
    ''' VintaSoft Imaging .NET SDK (Standard) (Vintasoft.Imaging.dll),
    ''' VintaSoft Document Cleanup .NET Plug-in (Vintasoft.Imaging.DocCleanup.dll),
    ''' VintaSoft OCR .NET Plug-in (Vintasoft.Imaging.Ocr.dll, Vintasoft.Imaging.Ocr.Tesseract.dll),
    ''' VintaSoft PDF .NET Plug-in (Vintasoft.Imaging.Pdf.dll, Vintasoft.Imaging.Pdf.Ocr.dll) and
    ''' and VintaSoft PDF .NET Plug-in (Writer) (Vintasoft.Pdf.dll) are necessary
    ''' for executing this sample.
    ''' </remarks>
    Public Shared Sub ScanImagesAndSaveAsSearchablePdfDocument(language As Vintasoft.Imaging.Ocr.OcrLanguage, outputPdfFilename As String)
        System.Console.WriteLine("Create TWAIN device manager...")
        Using deviceManager As New Vintasoft.Twain.DeviceManager()
            ' create PDF document
            Using pdfDocument As New Vintasoft.Imaging.Pdf.PdfDocument(outputPdfFilename, Vintasoft.Imaging.Pdf.PdfFormat.Pdf_14)
                ' create PDF document builder
                Dim documentBuilder As New Vintasoft.Imaging.Pdf.Ocr.PdfDocumentBuilder(pdfDocument)
                documentBuilder.ImageCompression = Vintasoft.Imaging.Pdf.PdfCompression.Auto
                documentBuilder.PageCreationMode = Vintasoft.Imaging.Pdf.Ocr.PdfPageCreationMode.ImageOverText

                System.Console.WriteLine("Create Tesseract OCR engine...")
                Using tesseractOcr As New Vintasoft.Imaging.Ocr.Tesseract.TesseractOcr()
                    ' create OCR engine manager
                    Dim engineManager As New Vintasoft.Imaging.Ocr.OcrEngineManager(tesseractOcr)

                    Dim settings As New Vintasoft.Imaging.Ocr.OcrEngineSettings(language)

                    System.Console.WriteLine("Open TWAIN device manager...")
                    deviceManager.Open()

                    Dim device As Vintasoft.Twain.Device = deviceManager.DefaultDevice

                    Dim acquireState As Vintasoft.Twain.AcquireModalState
                    Do
                        System.Console.WriteLine("Acquire image from scanner...")
                        acquireState = device.AcquireModal()
                        If acquireState = Vintasoft.Twain.AcquireModalState.ImageAcquired Then
                            ' create VintasoftImage
                            Using image As Vintasoft.Imaging.VintasoftImage = Vintasoft.Imaging.VintasoftImageGdiExtensions.Create(device.AcquiredImage.GetAsBitmap(), True)
                                ' preprocess image
                                ' BorderClear, Despeckle, Deskew, Segmentation
                                System.Console.WriteLine("Preprocess the image...")
                                Dim preprocessing As New Vintasoft.Imaging.ImageProcessing.Document.OcrPreprocessingCommand()
                                preprocessing.Binarization = Nothing
                                preprocessing.ExecuteInPlace(image)

                                ' recognize image
                                System.Console.WriteLine("Recognize the image...")
                                Dim page As Vintasoft.Imaging.Ocr.Results.OcrPage = engineManager.Recognize(image, settings, preprocessing.SegmentationTextRegions)

                                ' add page to PDF document
                                System.Console.WriteLine("Add page to PDF document...")
                                documentBuilder.AddPage(image, page)
                            End Using

                            ' dispose the acquired image
                            device.AcquiredImage.Dispose()
                        End If
                    Loop While acquireState <> Vintasoft.Twain.AcquireModalState.None

                    System.Console.WriteLine("Save changes in PDF document...")
                    pdfDocument.SaveChanges()
                End Using
            End Using
        End Using
    End Sub
End Class