TagsSupported Method

Summary

Checks whether the given file format supports tags.

Syntax

Objective-C

C++/CLI

Java

Python

public static bool TagsSupported( 
   RasterImageFormat format 
)

+ (BOOL)tagsSupported:(LTRasterImageFormat)format

public static boolean tagsSupported(RasterImageFormat format)

public: 
static bool TagsSupported(  
   RasterImageFormat format 
)

def TagsSupported(self,format):

Parameters

format
The RasterImageFormat to check

Return Value

true if the format supports tags; otherwise it is false.

Remarks

This is a helper method that can be used to detect if a certain raster file format supports tags. For example, ReadTag, ReadTags and EnumTags can be used to read the tags stored in a file. If the file format supports tags, such as JPEG or TIFF, then these methods will successfully return the tags stored.

However, if the format does not support tags, such as BMP, an exception will be thrown by the RasterCodecs objects. You can use TagsSupported to determine whether the file supports tags and only call the read tags methods if the return value is true.

Note that the RasterCodecs option uses this method internally to determine whether the file supports tags when the CodecsLoadOptions.Tags is set to true and only read the file tags if the file format supports them.

Example

Java

using Leadtools; 
using Leadtools.Codecs; 
using Leadtools.ImageProcessing; 
using Leadtools.ImageProcessing.Color; 
using Leadtools.Svg; 
 
 
public void MetadataLoadExample() 
{ 
   // Prompt the user for an image file 
   string imageFileName = Path.Combine(LEAD_VARS.ImagesDir, "test_GeoKey.TIF"); 
 
   // Initialize LEADTOOLS 
   using (RasterCodecs codecs = new RasterCodecs()) 
   { 
      // Get the file format 
      RasterImageFormat format; 
 
      using (CodecsImageInfo info = codecs.GetInformation(imageFileName, false)) 
      { 
         format = info.Format; 
      } 
 
      // Load the tags 
      IList<RasterTagMetadata> tags = null; 
      if (RasterCodecs.TagsSupported(format)) 
         tags = codecs.ReadTags(imageFileName, 1); 
 
      // Load the comments 
      IList<RasterCommentMetadata> comments = null; 
      if (RasterCodecs.CommentsSupported(format)) 
         comments = codecs.ReadComments(imageFileName, 1); 
 
      // Load the geo keys 
      IList<RasterTagMetadata> geoKeys = null; 
      if (RasterCodecs.GeoKeysSupported(format)) 
         geoKeys = codecs.ReadGeoKeys(imageFileName, 1); 
 
      // Load the markers 
      IList<RasterMarkerMetadata> markers = null; 
      if (RasterCodecs.MarkersSupported(format)) 
         markers = codecs.ReadMarkers(imageFileName); 
 
      string txtFileName = Path.Combine( 
         Path.GetDirectoryName(imageFileName), 
         Path.GetFileNameWithoutExtension(imageFileName) + "_metadata.txt"); 
 
      using (StreamWriter writer = File.CreateText(txtFileName)) 
      { 
         // Write the tags 
         WriteTags(writer, "Tags", tags); 
 
         // Write the comments 
         WriteComments(writer, comments); 
 
         // Write the geo keys (tags and geokeys use the same data type) 
         WriteTags(writer, "GeoKeys", geoKeys); 
 
         // Write the markers 
         WriteMarkers(writer, markers); 
      } 
 
      // Show the text file we created 
      Trace.Write(File.ReadAllText(txtFileName)); 
   } 
} 
 
private static void WriteTags(StreamWriter writer, string name, IList<RasterTagMetadata> tags) 
{ 
   writer.WriteLine("{0}:", name); 
 
   if (tags != null) 
   { 
      foreach (RasterTagMetadata tag in tags) 
      { 
         writer.WriteLine("Id: 0x{0}, data length: {1}", tag.Id.ToString("X"), tag.GetData().Length); 
      } 
   } 
   else 
   { 
      writer.WriteLine("Not supported"); 
   } 
 
   writer.WriteLine(); 
} 
 
private static void WriteComments(StreamWriter writer, IList<RasterCommentMetadata> comments) 
{ 
   writer.WriteLine("Comments:"); 
 
   if (comments != null) 
   { 
      foreach (RasterCommentMetadata comment in comments) 
      { 
         writer.WriteLine("Type: {0}, data length: {1}", comment.Type, comment.GetData().Length); 
      } 
   } 
   else 
   { 
      writer.WriteLine("Not supported"); 
   } 
 
   writer.WriteLine(); 
} 
 
private static void WriteMarkers(StreamWriter writer, IList<RasterMarkerMetadata> markers) 
{ 
   writer.WriteLine("Markers:"); 
 
   if (markers != null) 
   { 
      foreach (RasterMarkerMetadata marker in markers) 
      { 
         writer.WriteLine("ID: {0}, data length: {1}", marker.Id, marker.GetData().Length); 
      } 
   } 
   else 
   { 
      writer.WriteLine("Not supported"); 
   } 
 
   writer.WriteLine(); 
} 
 
static class LEAD_VARS 
{ 
   public const string ImagesDir = @"C:\LEADTOOLS23\Resources\Images"; 
}

 
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 metadataLoadExample() throws IOException { 
   final String LEAD_VARS_IMAGES_DIR = "C:\\LEADTOOLS23\\Resources\\Images"; 
   String imageFileName = combine(LEAD_VARS_IMAGES_DIR, "ocr1.tif"); 
   ILeadStream imageFileStream = LeadStreamFactory.create(imageFileName); 
   RasterCodecs codecs = new RasterCodecs(); 
 
   // Get the file format 
   RasterImageFormat format; 
   CodecsImageInfo info = codecs.getInformation(imageFileName, false); 
   format = info.getFormat(); 
 
   // Load the tags 
   List<RasterTagMetadata> tags = null; 
   assertTrue("tags are supported", RasterCodecs.tagsSupported(format)); 
   tags = codecs.readTags(imageFileStream, 1); 
   System.out.println("tags are supported"); 
 
   // Load the comments 
   List<RasterCommentMetadata> comments = null; 
   assertTrue("comments are supported", RasterCodecs.commentsSupported(format)); 
   comments = codecs.readComments(imageFileStream, 1); 
   System.out.println("comments are supported"); 
 
   // Load the geo keys 
   List<RasterTagMetadata> geoKeys = null; 
   assertTrue("geoKeys are supported", RasterCodecs.geoKeysSupported(format)); 
   geoKeys = codecs.readGeoKeys(imageFileStream, 1); 
   System.out.println("geoKeys are supported"); 
 
   // Load the markers 
   List<RasterMarkerMetadata> markers = null; 
   if (RasterCodecs.markersSupported(format)) 
      markers = codecs.readMarkers(imageFileStream); 
 
   File file = new File(imageFileName); 
   String txtFileName = file.getName().substring(0, file.getName().indexOf(".")) + "_metadata.txt"; 
   File txtFile = new File(txtFileName); 
   if (!txtFile.exists()) { 
      txtFile.createNewFile(); 
   } 
   FileWriter txtFileWriter = new FileWriter(txtFileName); 
   LeadStreamFactory.create(txtFileName); 
 
   // Write the tags 
   writeTags(txtFileWriter, "Tags", tags); 
 
   // Write the comments 
   writeComments(txtFileWriter, comments); 
 
   // Write the geo keys (tags and geokeys use the same data type) 
   writeTags(txtFileWriter, "GeoKeys", geoKeys); 
 
   // Write the markers 
   writeMarkers(txtFileWriter, markers); 
 
   // Show the text file we created 
   imageFileStream.close(); 
   txtFileWriter.close(); 
} 
 
private static void writeTags(FileWriter writer, String name, List<RasterTagMetadata> tags) throws IOException { 
   writer.write((name + ":")); 
 
   if (tags != null) { 
      for (RasterTagMetadata tag : tags) { 
         writer.write(String.format("Id: 0x%s, data length: %s%n", tag.getId(), tag.getData().length)); 
      } 
   } else { 
      writer.write("Not supported\n"); 
   } 
 
   writer.write("\n"); 
} 
 
private static void writeComments(FileWriter writer, List<RasterCommentMetadata> comments) throws IOException { 
   writer.write("Comments:"); 
 
   if (comments != null) { 
      for (RasterCommentMetadata comment : comments) { 
         writer.write(String.format("Type: %s, data length: %s%n", comment.getType(), comment.getData().length)); 
      } 
   } else { 
      writer.write("Not supported\n"); 
   } 
 
   writer.write("\n"); 
} 
 
private static void writeMarkers(FileWriter writer, List<RasterMarkerMetadata> markers) throws IOException { 
   writer.write("Markers:"); 
 
   if (markers != null) { 
      for (RasterMarkerMetadata marker : markers) { 
         writer.write("ID: %s, data length: %s", marker.getId(), marker.getData().length); 
      } 
   } else { 
      writer.write("Not supported"); 
   } 
 
   writer.write("\n"); 
}