''' <summary>
''' Acquires image area from SANE device.
''' </summary>
Public Sub AcquireImageAreaFromSaneDevice()
    ' create SANE device manager
    Using deviceManager As New Vintasoft.Sane.SaneLocalDeviceManager()
        ' open SANE device manager
        deviceManager.Open()

        ' get count of SANE 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 SANE device
        Dim device As Vintasoft.Sane.SaneLocalDevice = deviceManager.Devices(0)

        ' open SANE device
        device.Open()


        ' get the default scan area
        Dim defaultScanArea As VintasoftRectF = device.ScanArea
        ' set new scan area
        device.ScanArea = New VintasoftRectF(0, 0, defaultScanArea.Width, defaultScanArea.Height / 2)


        Dim acquiredImage As Vintasoft.Sane.SaneAcquiredImage
        Do
            Try
                ' acquire image from SANE device
                acquiredImage = device.AcquireImageSync()
                ' if image is received
                If acquiredImage IsNot Nothing Then
                    System.Console.WriteLine("Image is acquired.")
                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 device has more images to scan
        Loop While device.HasMoreImagesToScan

        ' close SANE device
        device.Close()

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

    System.Console.ReadLine()
End Sub

/// <summary>
/// Acquires image area from SANE device.
/// </summary>
public void AcquireImageAreaFromSaneDevice()
{
    // create SANE device manager
    using (Vintasoft.Sane.SaneLocalDeviceManager deviceManager = new Vintasoft.Sane.SaneLocalDeviceManager())
    {
        // open SANE device manager
        deviceManager.Open();

        // get count of SANE devices
        int deviceCount = deviceManager.Devices.Count;
        if (deviceCount == 0)
        {
            System.Console.WriteLine("Devices are not found.");
            return;
        }

        // select the first SANE device
        Vintasoft.Sane.SaneLocalDevice device = deviceManager.Devices[0];

        // open SANE device
        device.Open();


        // get the default scan area
        VintasoftRectF defaultScanArea = device.ScanArea;
        // set new scan area
        device.ScanArea = new VintasoftRectF(0, 0, defaultScanArea.Width, defaultScanArea.Height / 2);


        Vintasoft.Sane.SaneAcquiredImage acquiredImage;
        do
        {
            try
            {
                // acquire image from SANE device
                acquiredImage = device.AcquireImageSync();
                // if image is received
                if (acquiredImage != null)
                {
                    System.Console.WriteLine("Image is acquired.");
                }
                // 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 device has more images to scan
        while (device.HasMoreImagesToScan);

        // close SANE device
        device.Close();

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

    System.Console.ReadLine();
}