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DeleteTag(String,Int32,Int32) Method
See Also 
Leadtools.Codecs Namespace > RasterCodecs Class > DeleteTag Method : DeleteTag(String,Int32,Int32) Method



fileName
A System.String containing the name of the file from which to delete the tag.
pageNumber
The 1-based index of the page from which the tag will be deleted. Use -1 to delete the tag from the last page. Use 1 to delete the tag from the first page.
id
The ID of the tag in the TIFF file. The tag IDs are between 0 and 65535.
fileName
A System.String containing the name of the file from which to delete the tag.
pageNumber
The 1-based index of the page from which the tag will be deleted. Use -1 to delete the tag from the last page. Use 1 to delete the tag from the first page.
id
The ID of the tag in the TIFF file. The tag IDs are between 0 and 65535.
Deletes a tag from a file, if the file supports tags (TIFF or Exif).

Syntax

Visual Basic (Declaration) 
Overloads Public Sub DeleteTag( _
   ByVal fileName As String, _
   ByVal pageNumber As Integer, _
   ByVal id As Integer _
) 
Visual Basic (Usage)Copy Code
Dim instance As RasterCodecs
Dim fileName As String
Dim pageNumber As Integer
Dim id As Integer
 
instance.DeleteTag(fileName, pageNumber, id)
C# 
public void DeleteTag( 
   string fileName,
   int pageNumber,
   int id
)
C++/CLI 
public:
void DeleteTag( 
   String^ fileName,
   int pageNumber,
   int id
) 

Parameters

fileName
A System.String containing the name of the file from which to delete the tag.
pageNumber
The 1-based index of the page from which the tag will be deleted. Use -1 to delete the tag from the last page. Use 1 to delete the tag from the first page.
id
The ID of the tag in the TIFF file. The tag IDs are between 0 and 65535.

Example

This example will create a TIF file, add a certain tag to it then delete it

Visual BasicCopy Code
Public Sub TagExample()
      Dim codecs As RasterCodecs = New RasterCodecs()

      Dim srcFileName As String = Path.Combine(LEAD_VARS.ImagesDir, "Image1.cmp")
      Dim destFileName As String = Path.Combine(LEAD_VARS.ImagesDir, "Image1_PageNumberTag.tif")

      ' Convert the source file to TIF
      Console.WriteLine("Converting the source file to TIF")
      codecs.Convert(srcFileName, destFileName, RasterImageFormat.Tif, 0, 0, 24, Nothing)

      Const pageNumberTagId As Integer = 297
      Dim pageNumber As Integer = 7

      Dim writeTag As RasterTagMetadata = New RasterTagMetadata()
      writeTag.Id = pageNumberTagId
      writeTag.DataType = RasterTagMetadataDataType.Int32
      writeTag.FromInt32(New Integer() {pageNumber})

      Console.WriteLine("Writing the following tag to the file:")
      Console.WriteLine("  ID: {0}", writeTag.Id)
      Console.WriteLine("  DataType: {0}", writeTag.DataType)
      Console.Write("  Data: ")
      Dim writeTagData As Byte() = writeTag.GetData()
      Dim i As Integer = 0
      Do While i < writeTagData.Length
         Console.Write("{0:X} ", writeTagData(i))
         i += 1
      Loop
      Console.WriteLine()

      ' Add the tag
      Console.WriteLine("Writing the page number tag with data = {0} to the file", pageNumber)
      codecs.WriteTag(destFileName, 1, writeTag)

      ' Read the tag and make sure it is in the file
      Console.WriteLine("Reading the page number tag from the file")
      Dim readTag As RasterTagMetadata = codecs.ReadTag(destFileName, 1, pageNumberTagId)

      Console.WriteLine("Tag read from the file:")
      Console.WriteLine("  ID: {0}", readTag.Id)
      Console.WriteLine("  DataType: {0}", readTag.DataType)
      Console.Write("  Data: ")
      Dim readTagData As Byte() = readTag.GetData()
      i = 0
      Do While i < readTagData.Length
         Console.Write("{0:X} ", readTagData(i))
         i += 1
      Loop
      Console.WriteLine()

      Debug.Assert(writeTag.Id = readTag.Id)
      Debug.Assert(writeTag.DataType = readTag.DataType)
      Debug.Assert(writeTagData.Length = writeTagData.Length)
      i = 0
      Do While i < writeTagData.Length
         Debug.Assert(writeTagData(i) = readTagData(i))
         i += 1
      Loop

      ' Delete the tag from the file
      Console.WriteLine("Deleting the tag from the file")
      codecs.DeleteTag(destFileName, 1, pageNumberTagId)

      ' Make sure the tag is deleted
      Console.WriteLine("Reading the tag from the file again")
      readTag = codecs.ReadTag(destFileName, 1, pageNumberTagId)

      If readTag Is Nothing Then
         Console.WriteLine("Tag was not found")
      Else
         Console.WriteLine("Tag is found, this should not happen")
      End If

      Debug.Assert(readTag Is Nothing)

      ' Clean up
      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 TagExample()
   {
      RasterCodecs codecs = new RasterCodecs();

      string srcFileName = Path.Combine(LEAD_VARS.ImagesDir, "Image1.cmp");
      string destFileName = Path.Combine(LEAD_VARS.ImagesDir, "Image1_PageNumberTag.tif");

      // Convert the source file to TIF
      Console.WriteLine("Converting the source file to TIF");
      codecs.Convert(srcFileName, destFileName, RasterImageFormat.Tif, 0, 0, 24, null);

      const int pageNumberTagId = 297;
      int pageNumber = 7;

      RasterTagMetadata writeTag = new RasterTagMetadata();
      writeTag.Id = pageNumberTagId;
      writeTag.DataType = RasterTagMetadataDataType.Int32;
      writeTag.FromInt32(new int[] { pageNumber });

      Console.WriteLine("Writing the following tag to the file:");
      Console.WriteLine("  ID: {0}", writeTag.Id);
      Console.WriteLine("  DataType: {0}", writeTag.DataType);
      Console.Write("  Data: ");
      byte[] writeTagData = writeTag.GetData();
      for(int i = 0; i < writeTagData.Length; i++)
         Console.Write("{0:X} ", writeTagData[i]);
      Console.WriteLine();

      // Add the tag
      Console.WriteLine("Writing the page number tag with data = {0} to the file", pageNumber);
      codecs.WriteTag(destFileName, 1, writeTag);

      // Read the tag and make sure its in the file
      Console.WriteLine("Reading the page number tag from the file");
      RasterTagMetadata readTag = codecs.ReadTag(destFileName, 1, pageNumberTagId);

      Console.WriteLine("Tag read from the file:");
      Console.WriteLine("  ID: {0}", readTag.Id);
      Console.WriteLine("  DataType: {0}", readTag.DataType);
      Console.Write("  Data: ");
      byte[] readTagData = readTag.GetData();
      for(int i = 0; i < readTagData.Length; i++)
         Console.Write("{0:X} ", readTagData[i]);
      Console.WriteLine();

      Debug.Assert(writeTag.Id == readTag.Id);
      Debug.Assert(writeTag.DataType == readTag.DataType);
      Debug.Assert(writeTagData.Length == writeTagData.Length);
      for(int i = 0; i < writeTagData.Length; i++)
         Debug.Assert(writeTagData[i] == readTagData[i]);

      // Delete the tag from the file
      Console.WriteLine("Deleting the tag from the file");
      codecs.DeleteTag(destFileName, 1, pageNumberTagId);

      // Make sure the tag is deleted
      Console.WriteLine("Reading the tag from the file again");
      readTag = codecs.ReadTag(destFileName, 1, pageNumberTagId);

      if(readTag == null)
         Console.WriteLine("Tag was not found");
      else
         Console.WriteLine("Tag is found, this should not happen");

      Debug.Assert(readTag == null);

      // Clean up
      codecs.Dispose();
   }

static class LEAD_VARS
{
   public const string ImagesDir = @"C:\Users\Public\Documents\LEADTOOLS Images";
}
SilverlightCSharpCopy Code
public void TagExample(Stream inStreamCmp, Stream outStreamTif)
{
   RasterCodecs codecs = new RasterCodecs();
   // Convert the source file to TIF
   Debug.WriteLine("Converting the source file to TIF");
   codecs.Convert(inStreamCmp, outStreamTif, RasterImageFormat.Tif, 0, 0, 24, null);

   const int pageNumberTagId = 297;
   int pageNumber = 7;

   RasterTagMetadata writeTag = new RasterTagMetadata();
   writeTag.Id = pageNumberTagId;
   writeTag.DataType = RasterTagMetadataDataType.Int32;
   writeTag.FromInt32(new int[] { pageNumber });

   Debug.WriteLine("Writing the following tag to the file:");
   Debug.WriteLine("  ID: {0}", writeTag.Id);
   Debug.WriteLine("  DataType: {0}", writeTag.DataType);
   Debug.WriteLine("  Data: ");
   byte[] writeTagData = writeTag.GetData();
   for(int i = 0; i < writeTagData.Length; i++)
      Debug.WriteLine("{0:X} ", writeTagData[i]);
   Debug.WriteLine("");

   // Add the tag
   Debug.WriteLine("Writing the page number tag with data = {0} to the file", pageNumber);
   //FileStream fsDest = new FileStream(destFileName, FileMode.OpenOrCreate, FileAccess.ReadWrite);
   codecs.WriteTag(outStreamTif, 1, writeTag);

   // Read the tag and make sure its in the file
   Debug.WriteLine("Reading the page number tag from the file");
   RasterTagMetadata readTag = codecs.ReadTag(outStreamTif, 1, pageNumberTagId);
   Debug.WriteLine("Tag read from the file:");
   Debug.WriteLine("  ID: {0}", readTag.Id);
   Debug.WriteLine("  DataType: {0}", readTag.DataType);
   Debug.WriteLine("  Data: ");
   byte[] readTagData = readTag.GetData();
   for(int i = 0; i < readTagData.Length; i++)
      Debug.WriteLine("{0:X} ", readTagData[i]);
   Debug.WriteLine("");

   Debug.Assert(writeTag.Id == readTag.Id);
   Debug.Assert(writeTag.DataType == readTag.DataType);
   Debug.Assert(writeTagData.Length == writeTagData.Length);
   for(int i = 0; i < writeTagData.Length; i++)
      Debug.Assert(writeTagData[i] == readTagData[i]);

   // Delete the tag from the file
   Debug.WriteLine("Deleting the tag from the file");
   codecs.DeleteTag(outStreamTif, 1, pageNumberTagId);

   // Make sure the tag is deleted
   Debug.WriteLine("Reading the tag from the file again");
   readTag = codecs.ReadTag(outStreamTif, 1, pageNumberTagId);

   if(readTag == null)
      Debug.WriteLine("Tag was not found");
   else
      Debug.WriteLine("Tag is found, this should not happen");

   Debug.Assert(readTag == null);
}
SilverlightVBCopy Code
Public Sub TagExample(ByVal inStreamCmp As Stream, ByVal outStreamTif As Stream)
   Dim codecs As RasterCodecs = New RasterCodecs()
   ' Convert the source file to TIF
   Debug.WriteLine("Converting the source file to TIF")
   codecs.Convert(inStreamCmp, outStreamTif, RasterImageFormat.Tif, 0, 0, 24, Nothing)

   Const pageNumberTagId As Integer = 297
   Dim pageNumber As Integer = 7

   Dim writeTag As RasterTagMetadata = New RasterTagMetadata()
   writeTag.Id = pageNumberTagId
   writeTag.DataType = RasterTagMetadataDataType.Int32
   writeTag.FromInt32(New Integer() { pageNumber })

   Debug.WriteLine("Writing the following tag to the file:")
   Debug.WriteLine("  ID: {0}", writeTag.Id)
   Debug.WriteLine("  DataType: {0}", writeTag.DataType)
   Debug.WriteLine("  Data: ")
   Dim writeTagData As Byte() = writeTag.GetData()
   Dim i As Integer = 0
   Do While i < writeTagData.Length
      Debug.WriteLine("{0:X} ", writeTagData(i))
      i += 1
   Loop
   Debug.WriteLine("")

   ' Add the tag
   Debug.WriteLine("Writing the page number tag with data = {0} to the file", pageNumber)
   'FileStream fsDest = new FileStream(destFileName, FileMode.OpenOrCreate, FileAccess.ReadWrite);
   codecs.WriteTag(outStreamTif, 1, writeTag)

   ' Read the tag and make sure its in the file
   Debug.WriteLine("Reading the page number tag from the file")
   Dim readTag As RasterTagMetadata = codecs.ReadTag(outStreamTif, 1, pageNumberTagId)
   Debug.WriteLine("Tag read from the file:")
   Debug.WriteLine("  ID: {0}", readTag.Id)
   Debug.WriteLine("  DataType: {0}", readTag.DataType)
   Debug.WriteLine("  Data: ")
   Dim readTagData As Byte() = readTag.GetData()
   i = 0
   Do While i < readTagData.Length
      Debug.WriteLine("{0:X} ", readTagData(i))
      i += 1
   Loop
   Debug.WriteLine("")

   Debug.Assert(writeTag.Id = readTag.Id)
   Debug.Assert(writeTag.DataType = readTag.DataType)
   Debug.Assert(writeTagData.Length = writeTagData.Length)
   i = 0
   Do While i < writeTagData.Length
      Debug.Assert(writeTagData(i) = readTagData(i))
      i += 1
   Loop

   ' Delete the tag from the file
   Debug.WriteLine("Deleting the tag from the file")
   codecs.DeleteTag(outStreamTif, 1, pageNumberTagId)

   ' Make sure the tag is deleted
   Debug.WriteLine("Reading the tag from the file again")
   readTag = codecs.ReadTag(outStreamTif, 1, pageNumberTagId)

   If readTag Is Nothing Then
      Debug.WriteLine("Tag was not found")
   Else
      Debug.WriteLine("Tag is found, this should not happen")
   End If

   Debug.Assert(readTag Is Nothing)
End Sub

Remarks

If you want to delete the tag from a particular IFD in the file, set RasterCodecs.Options.Tiff.Save.UseImageFileDirectoryOffset to true, and set RasterCodecs.Options.Tiff.Save.ImageFileDirectoryOffset to the IFD in question. This method will delete tags only from the main IFDs that make up an image. Some TIFF tags are themselves SubIFDs. You can delete tags from such SubIFDs by using RasterCodecs.Options.Tiff.Save.UseImageFileDirectoryOffset and RasterCodecs.Options.Tiff.Save.ImageFileDirectoryOffset specifying the IFD as above.

Notes:

  • The Leadtools.Codecs.Cmp.dll codec is used to delete the tag from all the TIFF and Exif files.
  • Do not attempt to use this method to delete tags from inside the TagFound event. If you want to delete tags that you enumerate, use the TagFound event to add the tags to a list. Upon returning from EnumTags(String,Int32), you can delete all the tags from the list.
  • You should be careful when you delete non-custom tags (tags below 32768). If you delete the wrong tag, you might corrupt the TIF file!.

When you add or remove tags, the tags array at the end of the file is re-written. When you modify existing tags, the new tag value is added to the file and the IFD is modified as necessary. In all of these cases, there is no image recompression.

Requirements

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

See Also