CaptureDIB Method

Visual Basic
C#
WinRT C#
WinRT JavaScript
C++

public virtual IntPtr CaptureDIB()

'Declaration
 
Public Overridable Function CaptureDIB() As IntPtr

'Usage
 
Dim instance As CaptureCtrl
Dim value As IntPtr
 
value = instance.CaptureDIB()

public virtual IntPtr CaptureDIB()

 function Leadtools.Multimedia.CaptureCtrl.CaptureDIB()

public:
virtual IntPtr CaptureDIB();

Return Value

System.IntPtr

If the method succeeds, the caller must free the returned HDIB pointer by calling the Marshal.FreeHGlobal method. If the method fails, an error is raised. For more information, refer to the Error Codes.

Note: Internally this method calls StartCapture with the capture mode set to CaptureMode.Still. It then waits for the current capture delay setting specified by CaptureStillDelay before capturing the still DIB. Finally, it stops the graph by calling StopCapture.

Note: The frame data is retrieved from the underlying graph after the processing filters. If the capture needs to occur before the processing is completed use the LeadVideoCallBackFilter and place it first in the collection of processing filters.

Visual Basic
C#
WinRT C#
WinRT JavaScript
Silverlight C#
Silverlight VB

Copy Code

Public _form As CaptureCtrlForm = New CaptureCtrlForm()
      Public _capturectrl As CaptureCtrl = Nothing
      Public _result As Boolean = False
      Private _dibFile As String = Path.Combine(LEAD_VARS.MediaDir, "CaptureCtrl_CaptureDIBExample.dib")

      Public Sub CaptureDIBExample()
         ' reference the capture control
         _capturectrl = _form.CaptureCtrl

         Try
            ' select a video capture device
            If _capturectrl.VideoDevices("USB") Is Nothing Then
               Throw New Exception("No USB video device available")
            End If

            _capturectrl.VideoDevices("USB").Selected = True

            ' set a video compressor for the capture file
            _capturectrl.VideoCompressors.Mpeg4.Selected = True

            ' set still delay
            _capturectrl.CaptureStillDelay = 1000

            ' capture DIB
            Dim DIB As IntPtr = _capturectrl.CaptureDIB()

            ' check for the captured DIB handle
            If (DIB <> Nothing) Then
               _result = True
            End If

            ' free allocated global memory
            Marshal.FreeHGlobal(DIB)

         Catch e1 As Exception
            _result = False
         End Try
      End Sub

Public NotInheritable Class LEAD_VARS
   Public Const MediaDir As String = "C:\Program Files (x86)\LEAD Technologies\LEADTOOLS 175\Media";
End Class

public bool _result = false;
public CaptureCtrlForm _form = new CaptureCtrlForm();
public void CaptureDIBExample()
{
   // reference the capture control
   CaptureCtrl capturectrl = _form.CaptureCtrl;

   try
   {
       // set the video capture device. use your device's name here
      if (capturectrl.VideoDevices["Logitech"] == null)
         throw new Exception("No Logitech video device available");

      capturectrl.VideoDevices["Logitech"].Selected = true;

      // set a delay of 1 second to ensure that some capture devices
      // have time to adjust their gain
      capturectrl.CaptureStillDelay = 1000;

      // capture device independent bitmap
      IntPtr dib = capturectrl.CaptureDIB();

      _result = (dib != null);

      //free allocated global memory
      Marshal.FreeHGlobal(dib);
   }
   catch (COMException)
   {
      _result = false;
   }
   catch (Exception)
   {
      _result = false;
   }
}

Target Platforms: Windows 7, Windows Vista SP1 or later, Windows XP SP3, Windows Server 2008 (Server Core not supported), Windows Server 2008 R2 (Server Core supported with SP1 or later), Windows Server 2003 SP2

Reference

CaptureCtrl Class
CaptureCtrl Members