VintaSoft Twain .NET SDK 15.2: Documentation for .NET developer
In This Topic
    How to save eSCL acquired image to a JPEG file?
    In This Topic
    eSCL device can acquire image in raw format. SDK takes acquired image and creates EsclAcquiredImage object. Further eSCL acquired image can be saved to a JPEG file.
    Here is an example that demonstrates how to acquire an image in raw format from eSCL device and save the image to a JPEG file using JPEG encoder:
    /// <summary>
    /// Acquires image from eSCL device and saves image to a JPEG file.
    /// </summary>
    public void AcquireImageFromEsclDeviceAndSaveImageToJpegFile()
    {
        // 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 JPEG encoder settings
                        Vintasoft.EsclImageScanning.ImageEncoders.EsclJpegEncoderSettings jpegEncoderSettings =
                            new Vintasoft.EsclImageScanning.ImageEncoders.EsclJpegEncoderSettings();
                        // specify quality for JPEG image
                        jpegEncoderSettings.JpegQuality = 70;
    
                        // process acquired image
                        acquiredImage.Save("test.jpg", jpegEncoderSettings);
                    }
                    // 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 image from eSCL device and saves image to a JPEG file.
    ''' </summary>
    Public Sub AcquireImageFromEsclDeviceAndSaveImageToJpegFile()
        ' 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 JPEG encoder settings
                        Dim jpegEncoderSettings As New Vintasoft.EsclImageScanning.ImageEncoders.EsclJpegEncoderSettings()
                        ' specify quality for JPEG image
                        jpegEncoderSettings.JpegQuality = 70
    
                        ' process acquired image
                        acquiredImage.Save("test.jpg", jpegEncoderSettings)
                    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 acquire image as JPEG stream, i.e. eSCL device scans image, encodes scanned image to a JPEG format and returns JPEG stream.
    Here is an example that demonstrates how to acquire an image as JPEG stream from eSCL device and save received JPEG stream to a file:
    /// <summary>
    /// Synchronously acquire images as JPEG stream from eSCL device.
    /// </summary>
    public void SynchronouslyAcquireImagesAsJpegStreamFromEsclDevice()
    {
        // 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 JPEG stream from eSCL device
                    acquiredImageBytes = device.AcquireImageSyncAsFileStream(Vintasoft.EsclImageScanning.EsclScanDocumentFormat.JPEG);
                    // if image is received
                    if (acquiredImageBytes != null)
                    {
                        imageIndex++;
                        string filename = string.Format("scannedImage-{0}.jpg", 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 JPEG stream from eSCL device.
    ''' </summary>
    Public Sub SynchronouslyAcquireImagesAsJpegStreamFromEsclDevice()
        ' 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 JPEG stream from eSCL device
                    acquiredImageBytes = device.AcquireImageSyncAsFileStream(Vintasoft.EsclImageScanning.EsclScanDocumentFormat.JPEG)
                    ' if image is received
                    If acquiredImageBytes IsNot Nothing Then
                        imageIndex += 1
                        Dim filename As String = String.Format("scannedImage-{0}.jpg", 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