''' <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();
}