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GetOverlayImage Method
See Also  Example
Leadtools Namespace > RasterImage Class : GetOverlayImage Method



index
The index of the overlay being retrieved. This index is zero-based and should be less or equal than MaxOverlays.
mode
Determines how to retreive the image, possible values are:
Mode Description
RasterGetSetOverlayImageMode.Copy A copy of the overlay image is retrieved from the overlay list.
RasterGetSetOverlayImageMode.NoCopy The actual overlay image is retrieved. No copy is made. You should be careful when modifying the returned overlay image because you can modify/invalidate the entry in the overlay bitmap list.
RasterGetSetOverlayImageMode.Move The actual overlay image is retrieved. The image is also removed from the overlay list. This is recommended over RasterGetSetOverlayImageMode.NoCopy.
Gets the overlay image for the specified index.

Syntax

Visual Basic (Declaration) 
Public Function GetOverlayImage( _
   ByVal index As Integer, _
   ByVal mode As RasterGetSetOverlayImageMode _
) As RasterImage
Visual Basic (Usage)Copy Code
Dim instance As RasterImage
Dim index As Integer
Dim mode As RasterGetSetOverlayImageMode
Dim value As RasterImage
 
value = instance.GetOverlayImage(index, mode)
C# 
public RasterImage GetOverlayImage( 
   int index,
   RasterGetSetOverlayImageMode mode
)
C++/CLI 
public:
RasterImage^ GetOverlayImage( 
   int index,
   RasterGetSetOverlayImageMode mode
)

Parameters

index
The index of the overlay being retrieved. This index is zero-based and should be less or equal than MaxOverlays.
mode
Determines how to retreive the image, possible values are:
Mode Description
RasterGetSetOverlayImageMode.Copy A copy of the overlay image is retrieved from the overlay list.
RasterGetSetOverlayImageMode.NoCopy The actual overlay image is retrieved. No copy is made. You should be careful when modifying the returned overlay image because you can modify/invalidate the entry in the overlay bitmap list.
RasterGetSetOverlayImageMode.Move The actual overlay image is retrieved. The image is also removed from the overlay list. This is recommended over RasterGetSetOverlayImageMode.NoCopy.

Return Value

A RasterImage object that represents the overlay image of the specified index.

Example

Visual BasicCopy Code
Public Sub GetOverlayImageExample()
   RasterCodecs.Startup()
   Dim codecs As RasterCodecs = New RasterCodecs()
   ' load an image and set an overlay
   Dim image As RasterImage = codecs.Load(LeadtoolsExamples.Common.ImagesPath.Path + "IMAGE2.DIC", 0, CodecsLoadByteOrder.BgrOrGray, 1, 1)
   Dim imageOverlay1 As RasterImage = codecs.Load(LeadtoolsExamples.Common.ImagesPath.Path + "ULAY1.BMP", 1, CodecsLoadByteOrder.Rgb, 1, 1)
   Dim imageOverlay2 As RasterImage = codecs.Load(LeadtoolsExamples.Common.ImagesPath.Path + "ULAY2.BMP", 1, CodecsLoadByteOrder.Rgb, 1, 1)
   image.SetOverlayImage(0, imageOverlay1, RasterGetSetOverlayImageMode.Copy)
   image.SetOverlayImage(1, imageOverlay2, RasterGetSetOverlayImageMode.Copy)

   ' update the attributes of one of the overlays
   Dim attributes As RasterOverlayAttributes = image.GetOverlayAttributes(0, RasterGetSetOverlayAttributesFlags.Color Or RasterGetSetOverlayAttributesFlags.Flags Or RasterGetSetOverlayAttributesFlags.Origin Or RasterGetSetOverlayAttributesFlags.BitIndex)

   attributes.Color = New RasterColor(255, 255, 255)
   attributes.AutoPaint = True
   attributes.AutoProcess = True
   attributes.Origin = New Point(5, 5)
   attributes.BitPosition = image.BitsPerPixel - 1

   image.UpdateOverlayAttributes(0, attributes, RasterGetSetOverlayAttributesFlags.Color Or RasterGetSetOverlayAttributesFlags.Flags Or RasterGetSetOverlayAttributesFlags.Origin Or RasterGetSetOverlayAttributesFlags.BitIndex)


   Dim count As Integer = image.OverlayCount
   Dim i As Integer = 0
   Do While i < count
      Dim overlayTest As RasterImage = image.GetOverlayImage(i, RasterGetSetOverlayImageMode.NoCopy)
      Try
         Dim fileName As String = String.Format(LeadtoolsExamples.Common.ImagesPath.Path + "overlay{0}_copy.bmp", i)
         codecs.Save(overlayTest, fileName, RasterImageFormat.Bmp, 1)
      Finally
         CType(overlayTest, IDisposable).Dispose()
      End Try
      i += 1
   Loop

   image.Dispose()
   imageOverlay1.Dispose()
   imageOverlay2.Dispose()
   codecs.Dispose()
   RasterCodecs.Shutdown()
End Sub
C#Copy Code
public void GetOverlayImageExample() 
{ 
   RasterCodecs.Startup(); 
   RasterCodecs codecs = new RasterCodecs(); 
   // load an image and set an overlay 
   RasterImage image = codecs.Load(LeadtoolsExamples.Common.ImagesPath.Path + "IMAGE2.DCM", 0, CodecsLoadByteOrder.BgrOrGray, 1, 1); 
   RasterImage imageOverlay1 = codecs.Load(LeadtoolsExamples.Common.ImagesPath.Path + "ULAY1.BMP", 1, CodecsLoadByteOrder.Rgb, 1, 1); 
   RasterImage imageOverlay2 = codecs.Load(LeadtoolsExamples.Common.ImagesPath.Path + "ULAY2.BMP", 1, CodecsLoadByteOrder.Rgb, 1, 1); 
   image.SetOverlayImage(0, imageOverlay1, RasterGetSetOverlayImageMode.Copy); 
   image.SetOverlayImage(1, imageOverlay2, RasterGetSetOverlayImageMode.Copy); 
 
   // update the attributes of one of the overlays 
   RasterOverlayAttributes attributes = image.GetOverlayAttributes(0, 
      RasterGetSetOverlayAttributesFlags.Color | 
      RasterGetSetOverlayAttributesFlags.Flags | 
      RasterGetSetOverlayAttributesFlags.Origin | 
      RasterGetSetOverlayAttributesFlags.BitIndex); 
 
   attributes.Color = new RasterColor(255, 255, 255); 
   attributes.AutoPaint = true; 
   attributes.AutoProcess = true; 
   attributes.Origin = new Point(5, 5); 
   attributes.BitPosition = image.BitsPerPixel - 1; 
 
   image.UpdateOverlayAttributes( 
      0, 
      attributes, 
      RasterGetSetOverlayAttributesFlags.Color | 
      RasterGetSetOverlayAttributesFlags.Flags | 
      RasterGetSetOverlayAttributesFlags.Origin | 
      RasterGetSetOverlayAttributesFlags.BitIndex); 
 
 
   int count = image.OverlayCount; 
   for(int i = 0; i < count; i++) 
   { 
      using(RasterImage overlayTest = image.GetOverlayImage(i, RasterGetSetOverlayImageMode.NoCopy)) 
      { 
         string fileName = string.Format(LeadtoolsExamples.Common.ImagesPath.Path + "overlay{0}_copy.bmp", i); 
         codecs.Save(overlayTest, fileName, RasterImageFormat.Bmp, 1); 
      } 
   } 
 
   image.Dispose(); 
   imageOverlay1.Dispose(); 
   imageOverlay2.Dispose(); 
   codecs.Dispose(); 
   RasterCodecs.Shutdown(); 
}

Remarks

This method is available in the (Document/Medical only) Toolkits.

This method can be used to get a copy of the overlay image (RasterGetSetOverlayImageMode.Copy) or to get the image without making a copy (RasterGetSetOverlayImageMode.NoCopy or RasterGetSetOverlayImageMode.Move).

The quickest way to get the overlay image is to avoid making a copy. For more information on using RasterGetSetOverlayImageMode.NoCopy, refer to the "Remarks" section of SetOverlayImage.

For more information, refer to Overlay Overview.

Requirements

Target Platforms: Microsoft .NET Framework 3.0, Windows XP, Windows Server 2003 family, Windows Server 2008 family

See Also