VintaSoft Twain .NET SDK 15.2: Documentation for .NET developer
In This Topic
    How to save eSCL acquired image(s) to a PDF document?
    In This Topic
    eSCL device can return scanned image as raw image. SDK takes acquired image and creates EsclAcquiredImage object. Scanned image, which is represented by EsclAcquiredImage object, can be saved to a new PDF document or added to an existing PDF document.
    Here is an example that demonstrates how to acquire images from eSCL device and save images to a PDF document:
    /// <summary>
    /// Acquires images from eSCL device and saves images to a PDF file.
    /// </summary>
    public void AcquireImagesFromEsclDeviceAndSaveImagesToPdfFile()
    {
        // create eSCL device manager
        using (Vintasoft.EsclImageScanning.EsclDeviceManager deviceManager = new Vintasoft.EsclImageScanning.EsclDeviceManager())
        {
            // open eSCL device manager
            deviceManager.Open();
    
            // wait while the eSCL device manager searches for eSCL devices
            System.Threading.Thread.Sleep(deviceManager.DeviceSearchTimeout);
            // get count of eSCL devices
            int deviceCount = deviceManager.Devices.Count;
            if (deviceCount == 0)
            {
                System.Console.WriteLine("Devices are not found.");
                return;
            }
    
            // select the first eSCL device
            Vintasoft.EsclImageScanning.EsclDevice device = deviceManager.Devices[0];
    
            // open eSCL device
            device.Open();
    
            Vintasoft.EsclImageScanning.EsclAcquiredImage acquiredImage = null;
            do
            {
                try
                {
                    // acquire image from eSCL device
                    acquiredImage = device.AcquireImageSync();
                    // if image is received
                    if (acquiredImage != null)
                    {
                        System.Console.WriteLine("Image is acquired.");
    
                        // create TIFF encoder settings
                        Vintasoft.EsclImageScanning.ImageEncoders.EsclPdfEncoderSettings pdfEncoderSettings =
                            new Vintasoft.EsclImageScanning.ImageEncoders.EsclPdfEncoderSettings();
                        // specify that image must be added to a PDF file
                        pdfEncoderSettings.PdfMultiPage = true;
                        // specify image must be compressed with ZIP compression
                        pdfEncoderSettings.PdfImageCompression = Vintasoft.EsclImageScanning.ImageEncoders.EsclPdfImageCompression.ZIP;
    
                        // process acquired image
                        acquiredImage.Save("test.pdf", pdfEncoderSettings);
                    }
                    // if image is not received
                    else
                    {
                        System.Console.WriteLine("Scan is completed.");
                        break;
                    }
                }
                catch (System.Exception ex)
                {
                    System.Console.WriteLine(string.Format("Scan is failed: {0}", ex.Message));
                    break;
                }
            }
            // while image is acquired
            while (acquiredImage != null);
    
            // close eSCL device
            device.Close();
    
            // close eSCL device manager
            deviceManager.Close();
        }
    
        System.Console.ReadLine();
    }
    
    ''' <summary>
    ''' Acquires images from eSCL device and saves images to a PDF file.
    ''' </summary>
    Public Sub AcquireImagesFromEsclDeviceAndSaveImagesToPdfFile()
        ' create eSCL device manager
        Using deviceManager As New Vintasoft.EsclImageScanning.EsclDeviceManager()
            ' open eSCL device manager
            deviceManager.Open()
    
            ' wait while the eSCL device manager searches for eSCL devices
            System.Threading.Thread.Sleep(deviceManager.DeviceSearchTimeout)
            ' get count of eSCL devices
            Dim deviceCount As Integer = deviceManager.Devices.Count
            If deviceCount = 0 Then
                System.Console.WriteLine("Devices are not found.")
                Return
            End If
    
            ' select the first eSCL device
            Dim device As Vintasoft.EsclImageScanning.EsclDevice = deviceManager.Devices(0)
    
            ' open eSCL device
            device.Open()
    
            Dim acquiredImage As Vintasoft.EsclImageScanning.EsclAcquiredImage = Nothing
            Do
                Try
                    ' acquire image from eSCL device
                    acquiredImage = device.AcquireImageSync()
                    ' if image is received
                    If acquiredImage IsNot Nothing Then
                        System.Console.WriteLine("Image is acquired.")
    
                        ' create TIFF encoder settings
                        Dim pdfEncoderSettings As New Vintasoft.EsclImageScanning.ImageEncoders.EsclPdfEncoderSettings()
                        ' specify that image must be added to a PDF file
                        pdfEncoderSettings.PdfMultiPage = True
                        ' specify image must be compressed with ZIP compression
                        pdfEncoderSettings.PdfImageCompression = Vintasoft.EsclImageScanning.ImageEncoders.EsclPdfImageCompression.ZIP
    
                        ' process acquired image
                        acquiredImage.Save("test.pdf", pdfEncoderSettings)
                    Else
                        ' if image is not received
                        System.Console.WriteLine("Scan is completed.")
                        Exit Try
                    End If
                Catch ex As System.Exception
                    System.Console.WriteLine(String.Format("Scan is failed: {0}", ex.Message))
                    Exit Try
                End Try
                ' while image is acquired
            Loop While acquiredImage IsNot Nothing
    
            ' close eSCL device
            device.Close()
    
            ' close eSCL device manager
            deviceManager.Close()
        End Using
    
        System.Console.ReadLine()
    End Sub
    


    Also eSCL device can return scanned image as PDF stream, i.e. eSCL device scans image, encodes scanned image to a PDF format and returns PDF stream.
    Here is an example that demonstrates how to acquire an image as PDF stream from eSCL device and save received PDF stream to a file:
    /// <summary>
    /// Synchronously acquire images as PDF stream from eSCL device.
    /// </summary>
    public void SynchronouslyAcquireImagesAsPdfStreamFromEsclDevice()
    {
        // create eSCL device manager
        using (Vintasoft.EsclImageScanning.EsclDeviceManager deviceManager = new Vintasoft.EsclImageScanning.EsclDeviceManager())
        {
            // open eSCL device manager
            deviceManager.Open();
    
            // wait while the eSCL device manager searches for eSCL devices
            System.Threading.Thread.Sleep(deviceManager.DeviceSearchTimeout);
            // get count of eSCL devices
            int deviceCount = deviceManager.Devices.Count;
            if (deviceCount == 0)
            {
                System.Console.WriteLine("Devices are not found.");
                return;
            }
    
            // select the first eSCL device
            Vintasoft.EsclImageScanning.EsclDevice device = deviceManager.Devices[0];
    
            // open eSCL device
            device.Open();
    
            int imageIndex = 0;
            byte[] acquiredImageBytes = null;
            do
            {
                try
                {
                    // acquire image as PDF stream from eSCL device
                    acquiredImageBytes = device.AcquireImageSyncAsFileStream(Vintasoft.EsclImageScanning.EsclScanDocumentFormat.PDF);
                    // if image is received
                    if (acquiredImageBytes != null)
                    {
                        imageIndex++;
                        string filename = string.Format("scannedImage-{0}.pdf", imageIndex);
                        if (System.IO.File.Exists(filename))
                            System.IO.File.Delete(filename);
    
                        System.IO.File.WriteAllBytes(filename, acquiredImageBytes);
    
                        System.Console.WriteLine(string.Format("Acquired image is saved to a file '{0}'.", filename));
                    }
                    // if image is not received
                    else
                    {
                        System.Console.WriteLine("Scan is completed.");
                        break;
                    }
                }
                catch (System.Exception ex)
                {
                    System.Console.WriteLine(string.Format("Scan is failed: {0}", ex.Message));
                    break;
                }
            }
            // while image is acquired
            while (acquiredImageBytes != null);
    
            // close eSCL device
            device.Close();
    
            // close eSCL device manager
            deviceManager.Close();
        }
    
        System.Console.ReadLine();
    }
    
    ''' <summary>
    ''' Synchronously acquire images as PDF stream from eSCL device.
    ''' </summary>
    Public Sub SynchronouslyAcquireImagesAsPdfStreamFromEsclDevice()
        ' create eSCL device manager
        Using deviceManager As New Vintasoft.EsclImageScanning.EsclDeviceManager()
            ' open eSCL device manager
            deviceManager.Open()
    
            ' wait while the eSCL device manager searches for eSCL devices
            System.Threading.Thread.Sleep(deviceManager.DeviceSearchTimeout)
            ' get count of eSCL devices
            Dim deviceCount As Integer = deviceManager.Devices.Count
            If deviceCount = 0 Then
                System.Console.WriteLine("Devices are not found.")
                Return
            End If
    
            ' select the first eSCL device
            Dim device As Vintasoft.EsclImageScanning.EsclDevice = deviceManager.Devices(0)
    
            ' open eSCL device
            device.Open()
    
            Dim imageIndex As Integer = 0
            Dim acquiredImageBytes As Byte() = Nothing
            Do
                Try
                    ' acquire image as PDF stream from eSCL device
                    acquiredImageBytes = device.AcquireImageSyncAsFileStream(Vintasoft.EsclImageScanning.EsclScanDocumentFormat.PDF)
                    ' if image is received
                    If acquiredImageBytes IsNot Nothing Then
                        imageIndex += 1
                        Dim filename As String = String.Format("scannedImage-{0}.pdf", imageIndex)
                        If System.IO.File.Exists(filename) Then
                            System.IO.File.Delete(filename)
                        End If
    
                        System.IO.File.WriteAllBytes(filename, acquiredImageBytes)
    
                        System.Console.WriteLine(String.Format("Acquired image is saved to a file '{0}'.", filename))
                    Else
                        ' if image is not received
                        System.Console.WriteLine("Scan is completed.")
                        Exit Try
                    End If
                Catch ex As System.Exception
                    System.Console.WriteLine(String.Format("Scan is failed: {0}", ex.Message))
                    Exit Try
                End Try
                ' while image is acquired
            Loop While acquiredImageBytes IsNot Nothing
    
            ' close eSCL device
            device.Close()
    
            ' close eSCL device manager
            deviceManager.Close()
        End Using
    
        System.Console.ReadLine()
    End Sub