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



compression
Indicates the type of compression to use on the image.
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.
      Dim codecs As RasterCodecs = New RasterCodecs()

      ' Load the image compressed
      codecs.Options.Load.Compressed = True
      Dim image As RasterImage = codecs.Load(Path.Combine(LEAD_VARS.ImagesDir, "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(Path.Combine(LEAD_VARS.ImagesDir, "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()
   End Sub

Public NotInheritable Class LEAD_VARS
   Public Const ImagesDir As String = "C:\Users\Public\Documents\LEADTOOLS Images"
End Class
C#Copy Code
public void ChangeCompressionTest()
   {
      // This method toggles image compression.
      RasterCodecs codecs = new RasterCodecs();

      // Load the image compressed
      codecs.Options.Load.Compressed = true;
      RasterImage image = codecs.Load(Path.Combine(LEAD_VARS.ImagesDir, "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(Path.Combine(LEAD_VARS.ImagesDir, "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();
   }

static class LEAD_VARS
{
   public const string ImagesDir = @"C:\Users\Public\Documents\LEADTOOLS Images";
}
SilverlightCSharpCopy Code
SilverlightVBCopy Code

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: Silverlight, Windows XP, Windows Server 2003 family, Windows Server 2008 family, Windows Vista, Windows 7, MAC OS/X (Intel Only), Windows Phone 7

See Also