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Tags Property
See Also  Example
Leadtools Namespace > RasterImage Class : Tags Property



The collection of tag data used when reading and writing certain file formats (including TIFF).

Syntax

Visual Basic (Declaration)  
Public ReadOnly Property Tags As RasterCollection(Of RasterTagMetadata)
Visual Basic (Usage) Copy Code
Dim instance As RasterImage
Dim value As RasterCollection(Of RasterTagMetadata)
 
value = instance.Tags
C#  
public RasterCollection<RasterTagMetadata> Tags {get;}
C++/CLI  
public:
property RasterCollection<RasterTagMetadata>^ Tags {
   RasterCollection<RasterTagMetadata>^ get();
}

Return Value

A collection of RasterTagMetadata used when reading and writing certain file formats (including TIFF).

Example

Visual Basic Copy Code
Private Sub DisplayTag(ByVal tag As RasterTagMetadata)
   Select Case tag.DataType
      Case RasterTagMetadataDataType.Ascii
         MessageBox.Show("Tag " & tag.Id.ToString() & " = " & tag.ToAscii())
      Case RasterTagMetadataDataType.Byte
         MessageBox.Show("Tag " & tag.Id.ToString() & " = " & tag.ToByte()(0).ToString())
   End Select
End Sub
Public Sub TagsExample()
   RasterCodecs.Startup()
   Dim codecs As RasterCodecs = New RasterCodecs()
   Dim image As RasterImage = codecs.Load(LeadtoolsExamples.Common.ImagesPath.Path + "IMAGE1.CMP")

   'Ascii
   Dim tagDataAscii As RasterTagMetadata = New RasterTagMetadata()
   ' set the Copyright tag
   tagDataAscii.Id = &H8000
   tagDataAscii.DataType = RasterTagMetadataDataType.Ascii
   tagDataAscii.FromAscii("Test String")
   image.Tags.Add(tagDataAscii)

   'Byte
   Dim tagDataByte As RasterTagMetadata = tagDataAscii.Clone()
   tagDataAscii.Id = &H8001
   tagDataByte.DataType = RasterTagMetadataDataType.Byte
   Dim byteArray As Byte() = New Byte(0) {}
   byteArray(0) = 10
   tagDataByte.FromByte(byteArray)
   image.Tags.Add(tagDataByte)

   codecs.Options.Save.Tags = True
   codecs.Save(image, LeadtoolsExamples.Common.ImagesPath.Path + "IMAGE1_TAGS.TIF", RasterImageFormat.Tif, 0)
   ' load the tags together with the image

   Dim tag As RasterTagMetadata = codecs.ReadTag(LeadtoolsExamples.Common.ImagesPath.Path + "IMAGE1_TAGS.TIF", 1, &H8000)
   DisplayTag(tag)
   tag = codecs.ReadTag(LeadtoolsExamples.Common.ImagesPath.Path + "IMAGE1_TAGS.TIF", 1, &H8001)
   DisplayTag(tag)

   codecs.Dispose()
   RasterCodecs.Shutdown()
End Sub
C# Copy Code
private void DisplayTag(RasterTagMetadata tag) 
{ 
   switch(tag.DataType) 
   { 
      case RasterTagMetadataDataType.Ascii: 
         MessageBox.Show("Tag " + tag.Id.ToString() + " = " + tag.ToAscii()); 
         break; 
      case RasterTagMetadataDataType.Byte: 
         MessageBox.Show("Tag " + tag.Id.ToString() + " = " + tag.ToByte()[0].ToString()); 
         break; 
   } 
} 
public void TagsExample() 
{ 
   RasterCodecs.Startup(); 
   RasterCodecs codecs = new RasterCodecs(); 
   RasterImage image = codecs.Load(LeadtoolsExamples.Common.ImagesPath.Path + "IMAGE1.CMP"); 
 
   //Ascii 
   RasterTagMetadata tagDataAscii = new RasterTagMetadata(); 
   // set the Copyright tag 
   tagDataAscii.Id = 0x8000; 
   tagDataAscii.DataType = RasterTagMetadataDataType.Ascii; 
   tagDataAscii.FromAscii("Test String"); 
   image.Tags.Add(tagDataAscii); 
 
   //Byte 
   RasterTagMetadata tagDataByte = tagDataAscii.Clone(); 
   tagDataAscii.Id = 0x8001; 
   tagDataByte.DataType = RasterTagMetadataDataType.Byte; 
   byte[] byteArray = new byte[1]; 
   byteArray[0] = 10; 
   tagDataByte.FromByte(byteArray); 
   image.Tags.Add(tagDataByte); 
 
   codecs.Options.Save.Tags = true; 
   codecs.Save(image, LeadtoolsExamples.Common.ImagesPath.Path + "IMAGE1_TAGS.TIF", RasterImageFormat.Tif, 0); 
   // load the tags together with the image 
 
   RasterTagMetadata tag = codecs.ReadTag(LeadtoolsExamples.Common.ImagesPath.Path + "IMAGE1_TAGS.TIF", 1, 0x8000); 
   DisplayTag(tag); 
   tag = codecs.ReadTag(LeadtoolsExamples.Common.ImagesPath.Path + "IMAGE1_TAGS.TIF", 1, 0x8001); 
   DisplayTag(tag); 
 
   codecs.Dispose(); 
   RasterCodecs.Shutdown(); 
}

Remarks

Several formats allow you to store non-image data such as comments, tags, and markers.

You can manipulate the tags of an image by adding/removing RasterTagMetadata objects to this collection.

By setting the CodecsSaveOptions.Tags property to true before calling RasterCodecs.Save, you can save the tags in this collection when the image is saved into a file.

By setting the CodecsLoadOptions.Markers property to true before calling RasterCodecs.Load, you can load all the markers (if any) into this collection when an image is loaded from a file.

You can use the RasterCodecs.WriteTags method to save the tags directly to an existing file and the RasterCodecs.EnumTags to load the tags stored in an existing file.

For more information, refer to Non Image Data.

Requirements

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

See Also