VintaSoft Twain .NET SDK 15.3: Documentation for .NET developer
In This Topic
    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