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++/CLI

Java

Python

public bool Tags { get; set; }

@property (nonatomic, assign) BOOL tags;

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

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

Tags # get and set (CodecsLoadOptions)

Property Value

Value	Description
true	To enable automatic load of any tags found in the file.
false	To disable automatic load of tags in the file. The default value 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.

Java

using Leadtools; 
using Leadtools.Codecs; 
using Leadtools.ImageProcessing; 
using Leadtools.ImageProcessing.Color; 
using Leadtools.Svg; 
 
 
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(); 
}

 
import java.io.*; 
import java.net.*; 
import java.nio.file.Paths; 
import java.util.*; 
import java.time.Instant; 
import java.time.Duration; 
 
import org.junit.*; 
import org.junit.runner.JUnitCore; 
import org.junit.runner.Result; 
import org.junit.runner.notification.Failure; 
import static org.junit.Assert.*; 
 
import leadtools.*; 
import leadtools.codecs.*; 
import leadtools.codecs.RasterCodecs.FeedCallbackThunk; 
import leadtools.drawing.internal.*; 
import leadtools.imageprocessing.*; 
import leadtools.imageprocessing.color.ChangeIntensityCommand; 
import leadtools.svg.*; 
 
 
public void metadataAutoLoadExample() throws IOException { 
   final String LEAD_VARS_IMAGES_DIR = "C:\\LEADTOOLS23\\Resources\\Images"; 
   String imageFileName = combine(LEAD_VARS_IMAGES_DIR, "leadtools.pdf"); 
 
   // Initialize LEADTOOLS 
   RasterCodecs codecs = new RasterCodecs(); 
   CodecsLoadOptions loadOptions = codecs.getOptions().getLoad(); 
 
   // Make sure auto-loading of markers is turned off, otherwise, 
   // markers take precedence over loading the other metadata 
   loadOptions.setMarkers(false); 
 
   // Automatically load any tags, comments and geokeys found in this file 
   loadOptions.setTags(true); 
   loadOptions.setComments(true); 
   loadOptions.setGeoKeys(true); 
 
   // Now load the image 
   RasterImage image = codecs.load(imageFileName, 0, CodecsLoadByteOrder.BGR_OR_GRAY, 1, 1); 
   File file = new File(imageFileName); 
   String txtFileName = combine( 
         LEAD_VARS_IMAGES_DIR, file.getName().substring(0, file.getName().indexOf(".")) + "_metadata.txt"); 
   FileWriter txtFileWriter = new FileWriter(txtFileName); 
 
   // Show its tags 
   showTags(txtFileWriter, "Tags", image.getTags()); 
 
   // Show its comments 
   showComments(txtFileWriter, image.getComments()); 
 
   // Show its geo keys (tags and geokeys use the same data type) 
   showTags(txtFileWriter, "GeoKeys", image.getGeoKeys()); 
} 
 
private static void showTags(FileWriter writer, String name, RasterCollection<RasterTagMetadata> rasterCollection) 
      throws IOException { 
   writer.write(name + ":"); 
 
   for (RasterTagMetadata tag : rasterCollection) { 
      writer.write("Id: 0x" + tag.getId() + ", data length: " + tag.getData().length); 
   } 
 
   writer.write("\n"); 
} 
 
private static void showComments(FileWriter writer, RasterCollection<RasterCommentMetadata> comments) 
      throws IOException { 
   writer.write("Comments:"); 
 
   for (RasterCommentMetadata comment : comments) { 
      writer.write("Type: 0x" + comment.getType() + ", data length: " + comment.getData().length); 
   } 
 
   writer.write("\n"); 
}

Requirements

Target Platforms

Reference

CodecsLoadOptions Class

CodecsLoadOptions Members

Implementing TIFF Comments and Tags

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Help Version 23.0.2024.2.29

Leadtools.Codecs Assembly

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