VintaSoft Twain .NET SDK 15.5: Documentation for .NET developer
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How to acquire black-white images from WIA scanner?
In This Topic
If you want to acquire black-white images from WIA scanner, you should set the scan image pixel type (using WiaDevice.ScanImagePixelType property) to the WiaImagePixelType.BlackWhite value.

Supported scan image pixel types can be obtained using WiaDevice.GetSupportedImagePixelTypes method.

Here is an example that demonstrates how to acquire black-white images from WIA device:
/// <summary>
/// Acquires black-white images from WIA image scanner.
/// </summary>
public void AcquireBlackWhiteImageFromWiaDevice()
{
    // create WIA device manager
    using (Vintasoft.WiaImageScanning.WiaDeviceManager deviceManager = new Vintasoft.WiaImageScanning.WiaDeviceManager())
    {
        // open WIA device manager
        deviceManager.Open();

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

        // select the first WIA device
        Vintasoft.WiaImageScanning.WiaDevice device = deviceManager.Devices[0];

        // open WIA device
        device.Open();

        // get names of supported scan image pixel types
        Vintasoft.WiaImageScanning.WiaImagePixelType[] supportedImagePixelTypes = device.GetSupportedImagePixelTypes();
        foreach (Vintasoft.WiaImageScanning.WiaImagePixelType imagePixelType in supportedImagePixelTypes)
        {
            if (imagePixelType == Vintasoft.WiaImageScanning.WiaImagePixelType.BlackWhite)
            {
                // specify that black-white images must be acquired from WIA device
                device.ScanImagePixelType = imagePixelType;
                break;
            }
        }

        Vintasoft.WiaImageScanning.WiaAcquiredImage acquiredImage;
        do
        {
            try
            {
                // acquire image from WIA 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 image is acquired
        while (acquiredImage != null);

        // close WIA device
        device.Close();

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

    System.Console.ReadLine();
}
''' <summary>
''' Acquires black-white images from WIA device.
''' </summary>
Public Sub AcquireBlackWhiteImageFromWiaDevice()
    ' create WIA device manager
    Using deviceManager As New Vintasoft.WiaImageScanning.WiaDeviceManager()
        ' open WIA device manager
        deviceManager.Open()

        ' get count of WIA 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 WIA device
        Dim device As Vintasoft.WiaImageScanning.WiaDevice = deviceManager.Devices(0)

        ' open WIA device
        device.Open()

        ' get names of supported scan modes
        Dim supportedScanImagePixelTypes As Vintasoft.WiaImageScanning.WiaImagePixelType() = device.GetSupportedImagePixelTypes()
        For Each imagePixelType As Vintasoft.WiaImageScanning.WiaImagePixelType In supportedScanImagePixelTypes
            If imagePixelType = Vintasoft.WiaImageScanning.WiaImagePixelType.BlackWhite Then
                ' specify that black-white images must be acquired from WIA device
                device.ScanImagePixelType = imagePixelType
                Exit For
            End If
        Next

        Dim acquiredImage As Vintasoft.WiaImageScanning.WiaAcquiredImage
        Do
            Try
                ' acquire image from WIA 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 image is acquired
        Loop While acquiredImage IsNot Nothing

        ' close WIA device
        device.Close()

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

    System.Console.ReadLine()
End Sub