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



compression
Indicates the type of compression to use on the image.
Compresses or decompresses this RasterImage.

Syntax

Visual Basic (Declaration) 
Public Sub ChangeCompression( _
   ByVal compression As RasterCompression _
)
Visual Basic (Usage)Copy Code
Dim instance As RasterImage
Dim compression As RasterCompression
 
instance.ChangeCompression(compression)
C# 
public void ChangeCompression( 
   RasterCompression compression
)
C++/CLI 
public:
void ChangeCompression( 
   RasterCompression compression
)

Parameters

compression
Indicates the type of compression to use on the image.

Example

This example toggles image compression.

Visual BasicCopy Code
Public Sub ChangeCompressionTest()
   ' This method toggles image compression.
   RasterCodecs.Startup()
   Dim codecs As RasterCodecs = New RasterCodecs()

   ' Load the image compressed
   codecs.Options.Load.Compressed = True
   Dim image As RasterImage = codecs.Load(LeadtoolsExamples.Common.ImagesPath.Path + "OCR1.TIF")
   Dim str As String
   If image.IsCompressed Then
      str = "BEFORE - ImageSize: " & image.DataSize & " bytes, Type: " & ("Compressed")
   Else
      str = "BEFORE - ImageSize: " & image.DataSize & " bytes, Type: " & ("UnCompressed")
   End If
   Console.WriteLine(str, "ChangeCompression")
   If (image.IsCompressed = True) Then
      image.ChangeCompression(RasterCompression.None)
   Else
      image.ChangeCompression(RasterCompression.Rle)
   End If
   If image.IsCompressed Then
      str = "AFTER - ImageSize: " & image.DataSize & " bytes, Type: " & ("Compressed")
   Else
      str = "AFTER - ImageSize: " & image.DataSize & " bytes, Type: " & ("UnCompressed")
   End If
   Console.WriteLine(str, "ChangeCompression")

   ' Load the image super-compressed
   codecs.Options.Load.SuperCompressed = True
   image = codecs.Load(LeadtoolsExamples.Common.ImagesPath.Path + "IMAGE1.CMP")
   If image.IsSuperCompressed Then
      str = "BEFORE - ImageSize: " & image.DataSize & " bytes, Type: " & ("Compressed")
   Else
      str = "BEFORE - ImageSize: " & image.DataSize & " bytes, Type: " & ("UnCompressed")
   End If
   Console.WriteLine(str, "ChangeCompression")
   If (image.IsSuperCompressed = True) Then
      image.ChangeCompression(RasterCompression.None)
   Else
      image.ChangeCompression(RasterCompression.Super)
   End If
   If image.IsSuperCompressed Then
      str = "AFTER - ImageSize: " & image.DataSize & " bytes, Type: " & ("Compressed")
   Else
      str = "AFTER - ImageSize: " & image.DataSize & " bytes, Type: " & ("UnCompressed")
   End If
   Console.WriteLine(str, "ChangeCompression")

   image.Dispose()
   codecs.Dispose()
   RasterCodecs.Shutdown()
End Sub
C#Copy Code
public void ChangeCompressionTest() 
{ 
   // This method toggles image compression. 
   RasterCodecs.Startup(); 
   RasterCodecs codecs = new RasterCodecs(); 
 
   // Load the image compressed 
   codecs.Options.Load.Compressed = true; 
   RasterImage image = codecs.Load(LeadtoolsExamples.Common.ImagesPath.Path + "OCR1.TIF"); 
   String str = "BEFORE - ImageSize: " + image.DataSize + " bytes, Type: " + (image.IsCompressed ? "Compressed" : "UnCompressed"); 
   Console.WriteLine(str, "ChangeCompression"); 
   image.ChangeCompression((image.IsCompressed == true) ? RasterCompression.None : RasterCompression.Rle); 
   str = "AFTER - ImageSize: " + image.DataSize + " bytes, Type: " + (image.IsCompressed ? "Compressed" : "UnCompressed"); 
   Console.WriteLine(str, "ChangeCompression"); 
 
   // Load the image super-compressed 
   codecs.Options.Load.SuperCompressed = true; 
   image = codecs.Load(LeadtoolsExamples.Common.ImagesPath.Path + "IMAGE1.CMP"); 
   str = "BEFORE - ImageSize: " + image.DataSize + " bytes, Type: " + (image.IsSuperCompressed ? "Compressed" : "UnCompressed"); 
   Console.WriteLine(str, "ChangeCompression"); 
   image.ChangeCompression((image.IsSuperCompressed == true) ? RasterCompression.None : RasterCompression.Super); 
   str = "AFTER - ImageSize: " + image.DataSize + " bytes, Type: " + (image.IsSuperCompressed ? "Compressed" : "UnCompressed"); 
   Console.WriteLine(str, "ChangeCompression"); 
 
   image.Dispose(); 
   codecs.Dispose(); 
   RasterCodecs.Shutdown(); 
}

Remarks

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

For more information, refer to Speeding Up 1-Bit Documents.

This method does not support signed images.

Requirements

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

See Also