VintaSoft Twain .NET SDK 15.4: Documentation for .NET developer
Vintasoft.EsclImageScanning Namespace / EsclDevice Class / AcquireImageSync Methods / AcquireImageSync() Method
Syntax Exceptions Remarks Example Requirements SeeAlso
In This Topic
AcquireImageSync() Method (EsclDevice)
In This Topic
Synchronously acquires one image in raw format from this eSCL device.
Syntax
'Declaration

Public Overloads Function AcquireImageSync() As EsclAcquiredImage

public EsclAcquiredImage AcquireImageSync()

Return Value

Current state of the image acquisition process.
Exceptions
ExceptionDescription
Thrown if device is not opened OR current scanning job is not found OR device cannot return image in raw format.
Remarks

This method must be called in a loop until method will not return null, i.e. there is no more images to scan.

If eSCL device supports EsclScanDocumentFormat.OctetStream format, this method will do the following steps:

  • get image data in EsclScanDocumentFormat.OctetStream format
  • create EsclAcquiredImage object from raw image data

If eSCL device does not support EsclScanDocumentFormat.OctetStream format, this method will do the following steps:
  • get image data in EsclScanDocumentFormat.JPEG format - eSCL specification specifies that anyeSCL device must support JPEG format
  • decompress image data from JPEG format into raw format
  • create EsclAcquiredImage object from raw image data

Example

This C#/VB.NET code shows how to synchronously acquire images from eSCL device.


''' <summary>
''' Synchronously acquire images from eSCL device.
''' </summary>
Public Sub SynchronouslyAcquireImagesFromEsclDevice()
    ' 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 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
                    imageIndex += 1
                    Dim filename As String = String.Format("scannedImage-{0}.png", imageIndex)
                    If System.IO.File.Exists(filename) Then
                        System.IO.File.Delete(filename)
                    End If

                    acquiredImage.Save(filename)

                    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 acquiredImage IsNot Nothing

        ' close eSCL device
        device.Close()

        ' close eSCL device manager
        deviceManager.Close()
    End Using

    System.Console.ReadLine()
End Sub


/// <summary>
/// Synchronously acquire images from eSCL device.
/// </summary>
public void SynchronouslyAcquireImagesFromEsclDevice()
{
    // 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;
        Vintasoft.EsclImageScanning.EsclAcquiredImage acquiredImage = null;
        do
        {
            try
            {
                // acquire image from eSCL device
                acquiredImage = device.AcquireImageSync();
                // if image is received
                if (acquiredImage != null)
                {
                    imageIndex++;
                    string filename = string.Format("scannedImage-{0}.png", imageIndex);
                    if (System.IO.File.Exists(filename))
                        System.IO.File.Delete(filename);

                    acquiredImage.Save(filename);

                    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 (acquiredImage != null);

        // close eSCL device
        device.Close();

        // close eSCL device manager
        deviceManager.Close();
    }

    System.Console.ReadLine();
}

Requirements

Target Platforms: .NET 10; .NET 9; .NET 8; .NET 7; .NET 6; .NET Framework 4.8, 4.7, 4.6, 4.5

See Also