Tags Property

Summary

Gets or sets a value that indicates whether any tags found in the file should be automatically loaded.

Syntax

Objective-C

C++

Java

public bool Tags { get; set; }

Public Property Tags As Boolean

@property (nonatomic, assign) BOOL tags

public boolean getTags() 
public void setTags(boolean value)

public: 
property bool Tags { 
   bool get(); 
   void set (    bool ); 
}

Property Value

true to automatically load any tags found in the file; otherwise it is false.

Remarks

When the value of the Tags property is set to true, any subsequent load operation performed by this RasterCodecs object will automatically try to load all the tags found in the file and store them in the RasterImage.Tags collection of the resulting image.

Internally, the RasterCodecs object will call TagsSupported on the image and only tries to load the tags if the value returned was true.

When loading more than one page from a multipage file, only the tags found in the first page will be automatically loaded when the value of this property is set to true. To manually load all the tags in any page, use ReadTags.

You must set the value of the Markers property to false to enable automatically loading the tags. If the value of both Markers and Tags is set to true, then the markers will take take precedence and no tags will be loaded.

Note that any load method that uses tiles, offset or resizing will not load any file metadata automatically regardless of the value of this property.

Example

This example will browse to a file and load it along with any tags, geo-keys and comments found.

using Leadtools; 
using Leadtools.Codecs; 
using Leadtools.ImageProcessing; 
using Leadtools.ImageProcessing.Color; 
using Leadtools.Svg; 
using LeadtoolsExamples.Common; 
 
public void MetadataAutoLoadExample() 
{ 
   // Prompt the user for an image file 
   string imageFileName = PromptForFileName(); 
 
   // Initialize LEADTOOLS 
   using (RasterCodecs codecs = new RasterCodecs()) 
   { 
      CodecsLoadOptions loadOptions = codecs.Options.Load; 
 
      // Make sure auto-loading of markers is turned off, otherwise, 
      // markers take precedence over loading the other metadata 
      loadOptions.Markers = false; 
 
      // Automatically load any tags, comments and geokeys found in this file 
      loadOptions.Tags = true; 
      loadOptions.Comments = true; 
      loadOptions.GeoKeys = true; 
 
      // Now load the image 
      using (RasterImage image = codecs.Load(imageFileName, 0, CodecsLoadByteOrder.BgrOrGray, 1, 1)) 
      { 
         string txtFileName = Path.Combine( 
            Path.GetDirectoryName(imageFileName), 
            Path.GetFileNameWithoutExtension(imageFileName) + "_metadata.txt"); 
 
         using (StreamWriter writer = File.CreateText(txtFileName)) 
         { 
            // Show its tags 
            ShowTags(writer, "Tags", image.Tags); 
 
            // Show its comments 
            ShowComments(writer, image.Comments); 
 
            // Show its geo keys (tags and geokeys use the same data type) 
            ShowTags(writer, "GeoKeys", image.GeoKeys); 
         } 
 
         // Show the text file we created 
         System.Diagnostics.Process.Start(txtFileName); 
      } 
   } 
} 
 
private static void ShowTags(StreamWriter writer, string name, IList<RasterTagMetadata> tags) 
{ 
   writer.WriteLine("{0}:", name); 
 
   foreach (RasterTagMetadata tag in tags) 
   { 
      writer.WriteLine("Id: 0x{0}, data length: {1}", tag.Id.ToString("X"), tag.GetData().Length); 
   } 
 
   writer.WriteLine(); 
} 
 
private static void ShowComments(StreamWriter writer, IList<RasterCommentMetadata> comments) 
{ 
   writer.WriteLine("Comments:"); 
 
   foreach (RasterCommentMetadata comment in comments) 
   { 
      writer.WriteLine("Type: 0x{0}, data length: {1}", comment.Type, comment.GetData().Length); 
   } 
 
   writer.WriteLine(); 
}

Imports Leadtools 
Imports Leadtools.Codecs 
Imports Leadtools.ImageProcessing 
Imports Leadtools.ImageProcessing.Color 
Imports Leadtools.Drawing 
Imports Leadtools.Svg 
 
Public Sub MetadataAutoLoadExample() 
   ' Prompt the user for an image file 
   Dim imageFileName As String = PromptForFileName() 
 
   ' Initialize LEADTOOLS 
   Using codecs As New RasterCodecs() 
      Dim loadOptions As CodecsLoadOptions = codecs.Options.Load 
 
      ' Make sure auto-loading of markers is turned off, otherwise, 
      ' markers take precedence over loading the other metadata 
      loadOptions.Markers = False 
 
      ' Automatically load any tags, comments and geokeys found in this file 
      loadOptions.Tags = True 
      loadOptions.Comments = True 
      loadOptions.GeoKeys = True 
 
      ' Now load the image 
      Using image As RasterImage = codecs.Load(imageFileName, 0, CodecsLoadByteOrder.BgrOrGray, 1, 1) 
         Dim txtFileName As String = Path.Combine( 
            Path.GetDirectoryName(imageFileName), 
            Path.GetFileNameWithoutExtension(imageFileName) + "_metadata.txt") 
 
         Using writer As StreamWriter = File.CreateText(txtFileName) 
            ' Show its tags 
            ShowTags(writer, "Tags", image.Tags) 
 
            ' Show its comments 
            ShowComments(writer, image.Comments) 
 
            ' Show its geo keys (tags and geokeys use the same data type) 
            ShowTags(writer, "GeoKeys", image.GeoKeys) 
         End Using 
 
         ' Show the text file we created 
         System.Diagnostics.Process.Start(txtFileName) 
      End Using 
   End Using 
End Sub 
 
Private Shared Sub ShowTags(ByVal writer As StreamWriter, ByVal name As String, ByVal tags As IList(Of RasterTagMetadata)) 
   writer.WriteLine("{0}:", name) 
 
   For Each tag As RasterTagMetadata In tags 
      writer.WriteLine("Id: 0x{0}, data length: {1}", tag.Id.ToString("X"), tag.GetData().Length) 
   Next 
 
   writer.WriteLine() 
End Sub 
 
Private Shared Sub ShowComments(ByVal writer As StreamWriter, ByVal comments As IList(Of RasterCommentMetadata)) 
   writer.WriteLine("Comments:") 
 
   For Each comment As RasterCommentMetadata In comments 
      writer.WriteLine("Type: 0x{0}, data length: {1}", comment.Type, comment.GetData().Length) 
   Next 
 
   writer.WriteLine() 
End Sub

c#[Silverlight C# Example] 
using Leadtools; 
using Leadtools.Codecs; 
using Leadtools.Examples; 
using Leadtools.ImageProcessing; 
using Leadtools.ImageProcessing.Color; 
using Leadtools.Windows.Media; 
 
public void MetadataAutoLoadExample(Stream inStreamImage, StreamWriter outStreamText) 
{ 
   // Initialize LEADTOOLS 
   RasterCodecs codecs = new RasterCodecs(); 
   { 
      CodecsLoadOptions loadOptions = codecs.Options.Load; 
 
      // Make sure auto-loading of markers is turned off, otherwise, 
      // markers take precedence over loading the other metadata 
      loadOptions.Markers = false; 
 
      // Automatically load any tags, comments and geokeys found in this file 
      loadOptions.Tags = true; 
      loadOptions.Comments = true; 
      loadOptions.GeoKeys = true; 
 
      using (RasterImage image = codecs.Load(inStreamImage, 0, CodecsLoadByteOrder.BgrOrGray, 1, 1)) 
      { 
         // Show its tags 
         ShowTags(outStreamText, "Tags", image.Tags); 
 
         // Show its comments 
         ShowComments(outStreamText, image.Comments); 
 
         // Show its geo keys (tags and geokeys use the same data type) 
         ShowTags(outStreamText, "GeoKeys", image.GeoKeys); 
      } 
   } 
} 
 
private static void ShowTags(StreamWriter writer, string name, RasterCollection<RasterTagMetadata> tags) 
{ 
   writer.WriteLine("{0}:", name); 
 
   foreach (RasterTagMetadata tag in tags) 
   { 
      writer.WriteLine("Id: 0x{0}, data length: {1}", tag.Id.ToString("X"), tag.GetData().Length); 
   } 
 
   writer.WriteLine(); 
} 
 
private static void ShowComments(StreamWriter writer, RasterCollection<RasterCommentMetadata> comments) 
{ 
   writer.WriteLine("Comments:"); 
 
   foreach (RasterCommentMetadata comment in comments) 
   { 
      writer.WriteLine("Type: 0x{0}, data length: {1}", comment.Type, comment.GetData().Length); 
   } 
 
   writer.WriteLine(); 
} 
vb[Silverlight VB Example] 
Imports Leadtools 
Imports Leadtools.Codecs 
Imports Leadtools.ImageProcessing 
Imports Leadtools.ImageProcessing.Color 
Imports Leadtools.Windows.Media 
 
Public Sub MetadataAutoLoadExample(ByVal inStreamImage As Stream, ByVal outStreamText As StreamWriter) 
   ' Initialize LEADTOOLS 
   Dim codecs As RasterCodecs = New RasterCodecs() 
   Dim loadOptions As CodecsLoadOptions = codecs.Options.Load 
 
   ' Make sure auto-loading of markers is turned off, otherwise, 
   ' markers take precedence over loading the other metadata 
   loadOptions.Markers = False 
 
   ' Automatically load any tags, comments and geokeys found in this file 
   loadOptions.Tags = True 
   loadOptions.Comments = True 
   loadOptions.GeoKeys = True 
 
   Using image As RasterImage = codecs.Load(inStreamImage, 0, CodecsLoadByteOrder.BgrOrGray, 1, 1) 
      ' Show its tags 
      ShowTags(outStreamText, "Tags", image.Tags) 
 
      ' Show its comments 
      ShowComments(outStreamText, image.Comments) 
 
      ' Show its geo keys (tags and geokeys use the same data type) 
      ShowTags(outStreamText, "GeoKeys", image.GeoKeys) 
   End Using 
End Sub 
 
Private Shared Sub ShowTags(ByVal writer As StreamWriter, ByVal name As String, ByVal tags As RasterCollection(Of RasterTagMetadata)) 
   writer.WriteLine("{0}:", name) 
 
   For Each tag As RasterTagMetadata In tags 
      writer.WriteLine("Id: 0x{0}, data length: {1}", tag.Id.ToString("X"), tag.GetData().Length) 
   Next tag 
 
   writer.WriteLine() 
End Sub 
 
Private Shared Sub ShowComments(ByVal writer As StreamWriter, ByVal comments As RasterCollection(Of RasterCommentMetadata)) 
   writer.WriteLine("Comments:") 
 
   For Each comment As RasterCommentMetadata In comments 
      writer.WriteLine("Type: 0x{0}, data length: {1}", comment.Type, comment.GetData().Length) 
   Next comment 
 
   writer.WriteLine() 
End Sub

Requirements

Target Platforms

Reference

CodecsLoadOptions Class

CodecsLoadOptions Members

Implementing TIFF Comments and Tags

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Help Version 20.0.2020.4.3

Leadtools.Codecs Assembly

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