VintaSoft Twain .NET SDK 15.2: Documentation for .NET developer
In This Topic
    How to acquire black-white images from eSCL scanner?
    In This Topic
    If you want to acquire black-white images from eSCL scanner, you should set the scan color mode (using EsclDevice.ScanColorMode property) to the EsclScanColorMode.BlackAndWhite1 value.

    Not all eSCL devices allows to acquire black-white images. Supported scan color modes can be obtained using EsclDevice.GetSupportedScanColorModes method.

    Here is an example that demonstrates how to acquire black-white images from eSCL device:
    /// <summary>
    /// Acquires black-white images from eSCL device.
    /// </summary>
    public void AcquireBlackWhiteImageFromEsclDevice()
    {
        // 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();
    
    
            // get names of supported scan modes
            Vintasoft.EsclImageScanning.EsclScanColorMode[] supportedScanColorModes = device.GetSupportedScanColorModes();
            foreach (Vintasoft.EsclImageScanning.EsclScanColorMode supportedScanMode in supportedScanColorModes)
            {
                if (supportedScanMode == Vintasoft.EsclImageScanning.EsclScanColorMode.BlackAndWhite1)
                {
                    // specify that black-white images must be acquired from eSCL device
                    device.ScanColorMode = supportedScanMode;
                    break;
                }
            }
    
    
            Vintasoft.EsclImageScanning.EsclAcquiredImage acquiredImage;
            do
            {
                try
                {
                    // acquire image from eSCL 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 eSCL device
            device.Close();
    
            // close eSCL device manager
            deviceManager.Close();
        }
    
        System.Console.ReadLine();
    }
    
    ''' <summary>
    ''' Acquires black-white images from eSCL device.
    ''' </summary>
    Public Sub AcquireBlackWhiteImageFromEsclDevice()
        ' 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()
    
    
            ' get names of supported scan modes
            Dim supportedScanColorModes As Vintasoft.EsclImageScanning.EsclScanColorMode() = device.GetSupportedScanColorModes()
            For Each supportedScanMode As Vintasoft.EsclImageScanning.EsclScanColorMode In supportedScanColorModes
                If supportedScanMode = Vintasoft.EsclImageScanning.EsclScanColorMode.BlackAndWhite1 Then
                    ' specify that black-white images must be acquired from eSCL device
                    device.ScanColorMode = supportedScanMode
                    Exit For
                End If
            Next
    
    
            Dim acquiredImage As Vintasoft.EsclImageScanning.EsclAcquiredImage
            Do
                Try
                    ' acquire image from eSCL 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 eSCL device
            device.Close()
    
            ' close eSCL device manager
            deviceManager.Close()
        End Using
    
        System.Console.ReadLine()
    End Sub