ChangeCompression Method

Compresses or decompresses this RasterImage.

Syntax

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

public void ChangeCompression( 
   RasterCompression compression
)

'Declaration
 
Public Sub ChangeCompression( _
   ByVal compression As RasterCompression _
)

'Usage
 
Dim instance As RasterImage
Dim compression As RasterCompression
 
instance.ChangeCompression(compression)

public void ChangeCompression( 
   RasterCompression compression
)

 function Leadtools.RasterImage.ChangeCompression( 
   compression 
)

public:
void ChangeCompression( 
   RasterCompression compression
)

Parameters

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

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.

Example

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

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

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";
}

RasterImageExamples.prototype.ChangeCompressionTest = function ( )
{
   Tools.SetLicense ( ) ;
   with ( Leadtools ) 
   {
      with ( Leadtools.Codecs ) 
      {
         // This method toggles image compression.
         var codecs = new RasterCodecs();

         // Load the image compressed
         codecs.options.load.compressed = true;
         var srcFileName = "Assets\\OCR1.TIF";
         var image ;
         return Tools.AppInstallFolder().getFileAsync(srcFileName).then(function (loadFile) {
            return codecs.loadAsync(LeadStreamFactory.create(loadFile))
         })
         .then(function (img) {
            image = img;
            console.assert(image.isCompressed, "image.isCompressed");

            var str = "BEFORE - ImageSize: " + image.dataSize + " bytes, Type: " + (image.isCompressed ? "Compressed" : "UnCompressed");
            console.info(str, " ChangeCompression");
            image.changeCompression((image.isCompressed == true) ? RasterCompression.none : RasterCompression.rle);
            str = "AFTER - ImageSize: " + image.dataSize + " bytes, Type: " + (image.isCompressed ? "Compressed" : "UnCompressed");
            console.info(str, " ChangeCompression");
            image.close();

            // Load the image super-compressed
            codecs.options.load.superCompressed = true;
            srcFileName = "Assets\\IMAGE1.CMP";
            return Tools.AppInstallFolder().getFileAsync(srcFileName)
         })
         .then(function (loadFile) {
            return codecs.loadAsync(LeadStreamFactory.create(loadFile))
         })
         .then(function (img) {
            image = img;
            console.assert(image.isSuperCompressed, "image.IsSuperCompressed");

            str = "BEFORE - ImageSize: " + image.dataSize + " bytes, Type: " + (image.isSuperCompressed ? "Compressed" : "UnCompressed");
            console.info(str, " ChangeCompression");
            image.changeCompression((image.isSuperCompressed == true) ? RasterCompression.none : RasterCompression.super);
            str = "AFTER - ImageSize: " + image.dataSize + " bytes, Type: " + (image.isSuperCompressed ? "Compressed" : "UnCompressed");
            console.info(str, " ChangeCompression");

            image.close();
            codecs.close();
         });
      }
   }
}

[TestMethod]
public async Task ChangeCompressionTest()
{
   // This method toggles image compression.
   RasterCodecs codecs = new RasterCodecs();
   // Load the image compressed
   codecs.Options.Load.Compressed = true;
   string srcFileName = @"Assets\OCR1.TIF";
   StorageFile loadFile = await Tools.AppInstallFolder.GetFileAsync(srcFileName);
   RasterImage image = await codecs.LoadAsync(LeadStreamFactory.Create(loadFile));
   Assert.IsTrue(image.IsCompressed);

   String str = "BEFORE - ImageSize: " + image.DataSize + " bytes, Type: " + (image.IsCompressed ? "Compressed" : "UnCompressed");
   Debug.WriteLine(str, "ChangeCompression");
   image.ChangeCompression((image.IsCompressed == true) ? RasterCompression.None : RasterCompression.Rle);
   str = "AFTER - ImageSize: " + image.DataSize + " bytes, Type: " + (image.IsCompressed ? "Compressed" : "UnCompressed");
   Debug.WriteLine(str, "ChangeCompression");
   image.Dispose();

   // Load the image super-compressed
   codecs.Options.Load.SuperCompressed = true;
   srcFileName = @"Assets\IMAGE1.CMP";
   loadFile = await Tools.AppInstallFolder.GetFileAsync(srcFileName);
   image = await codecs.LoadAsync(LeadStreamFactory.Create(loadFile));
   Assert.IsTrue(image.IsSuperCompressed);

   str = "BEFORE - ImageSize: " + image.DataSize + " bytes, Type: " + (image.IsSuperCompressed ? "Compressed" : "UnCompressed");
   Debug.WriteLine(str, "ChangeCompression");
   image.ChangeCompression((image.IsSuperCompressed == true) ? RasterCompression.None : RasterCompression.Super);
   str = "AFTER - ImageSize: " + image.DataSize + " bytes, Type: " + (image.IsSuperCompressed ? "Compressed" : "UnCompressed");
   Debug.WriteLine(str, "ChangeCompression");

   image.Dispose();
   codecs.Dispose();
}

Requirements

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

RasterImage Class
RasterImage Members