Working with Markers

private static string ReadDescriptionComment(RasterCodecs rasterCodecsInstance, string fileName) 
{ 
   // Get the file format 
   using(CodecsImageInfo info = rasterCodecsInstance.GetInformation(fileName, false)) 
   { 
      // Check if this file format supports comment fields 
      if(RasterCodecs.CommentsSupported(info.Format)) 
      { 
         // Yes, read it 
         RasterCommentMetadata comment = rasterCodecsInstance.ReadComment(fileName, 1, RasterCommentMetadataType.Description); 
         return comment.ToAscii(); 
      } 
      else 
      { 
         // No, return a default comment 
         return "Description comment not supported"; 
      } 
   } 
} 

private static void ReadTagById(RasterCodecs rasterCodecsInstance, string fileName) 
{ 
   // RasterCodecs.ReadTag will throw an exception if fileName does not 
   // support tags. If required, use RasterCodecs.TagsSupported first 
              
   const int exifCopyrightTagId = 0x8298; 
              
   RasterTagMetadata tag = rasterCodecsInstance.ReadTag(fileName, 1, exifCopyrightTagId); 
   if(tag != null) 
   { 
      // Tag is found, show the value 
      Console.WriteLine(tag.ToAscii()); 
   } 
} 

private static void ReadCommentById(RasterCodecs rasterCodecsInstance, string fileName) 
{ 
   // RasterCodecs.ReadComment will throw an exception if fileName does not 
   // support comments. If required, use RasterCodecs.CommentsSupported first 
              
   RasterCommentMetadata comment = rasterCodecsInstance.ReadComment(fileName, 1, RasterCommentMetadataType.Description); 
   if(comment != null) 
   { 
      // comment is found, show the value 
      Console.WriteLine(comment.ToAscii()); 
   } 
} 

private static void WriteTagById(RasterCodecs rasterCodecsInstance, string fileName) 
{ 
   // Create the tag 
   const int exifCopyrightTagId = 0x8298; 
   RasterTagMetadata tag = new RasterTagMetadata(exifCopyrightTagId, RasterTagMetadataDataType.Ascii, null); 
   tag.FromAscii("Copyright (c) My Company"); 
              
   // Write it to the file 
   rasterCodecsInstance.WriteTag(fileName, 1, tag); 
} 

private static void WriteCommentById(RasterCodecs rasterCodecsInstance, string fileName) 
{ 
   // Create the comment 
   RasterCommentMetadata comment = new RasterCommentMetadata(RasterCommentMetadataType.Description, null); 
   comment.FromAscii("My description"); 
              
   // Write it to the file 
   rasterCodecsInstance.WriteComment(fileName, 1, comment); 
} 

private static void ReadAllTagsWithoutLoadingImage(RasterCodecs rasterCodecsInstance, string fileName) 
{ 
   // RasterCodecs.ReadTags will throw an exception if fileName does not 
   // support tags. If required, use RasterCodecs.TagsSupported first 
              
   RasterCollection<RasterTagMetadata> tags = rasterCodecsInstance.ReadTags(fileName, 1); 
   foreach(RasterTagMetadata tag in tags) 
   { 
      // Process tag 
      System.Diagnostics.Trace.WriteLine("Tag found, id = " + tag.Id.ToString("X")); 
              
      // The tag data can be obtained with tag.GetData() or the various .ToXXX methods 
   } 
} 

private static void ReadAllTagsWithoutData(RasterCodecs rasterCodecsInstance, string fileName) 
{ 
   // RasterCodecs.EnumTags will throw an exception if fileName does not 
   // support tags. If required, use RasterCodecs.TagsSupported first 
              
   rasterCodecsInstance.TagFound += new EventHandler<CodecsEnumTagsEventArgs>(rasterCodecsInstance_TagFound); 
   rasterCodecsInstance.EnumTags(fileName, 1); 
   rasterCodecsInstance.TagFound -= new EventHandler<CodecsEnumTagsEventArgs>(rasterCodecsInstance_TagFound); 
} 
              
private static void rasterCodecsInstance_TagFound(object sender, CodecsEnumTagsEventArgs e) 
{ 
   // Show the tag ID 
   System.Diagnostics.Trace.WriteLine("Tag found, id = " + e.Id.ToString("X")); 
} 

private static void ReadAllCommentsWithoutLoadingImage(RasterCodecs rasterCodecsInstance, string fileName) 
{ 
   // RasterCodecs.ReadComments will throw an exception if fileName does not 
   // support comments. If required, use RasterCodecs.CommentsSupported first 
              
   RasterCollection<RasterCommentMetadata> comments = rasterCodecsInstance.ReadComments(fileName, 1); 
   foreach(RasterCommentMetadata comment in comments) 
   { 
      // Process comment 
      System.Diagnostics.Trace.WriteLine("Comment found, type = " + comment.Type.ToString()); 
   } 
} 

private static void WriteTagsWithoutLoadingImage(RasterCodecs rasterCodecsInstance, string fileName) 
{ 
   // RasterCodecs.WriteTags will throw an exception if fileName does not 
   // support tags. If required, use RasterCodecs.TagsSupported first 
              
   // Create the tags 
   const int exifCopyrightTagId = 0x8298; 
   const int exifImageTitleTagId = 0x010E; 
              
   RasterCollection<RasterTagMetadata> tags = new RasterCollection<RasterTagMetadata>(); 
              
   RasterTagMetadata tag = new RasterTagMetadata(exifCopyrightTagId, RasterTagMetadataDataType.Ascii, null); 
   tag.FromAscii("Copyright (c) My Company"); 
   tags.Add(tag); 
              
   tag = new RasterTagMetadata(exifImageTitleTagId, RasterTagMetadataDataType.Ascii, null); 
   tag.FromAscii("My Image"); 
   tags.Add(tag); 
              
   // Write them to the file 
   rasterCodecsInstance.WriteTags(fileName, 1, tags); 
} 

private static void WriteCommentsWithoutLoadingImage(RasterCodecs rasterCodecsInstance, string fileName) 
{ 
   // RasterCodecs.WriteComments will throw an exception if fileName does not 
   // support comments. If required, use RasterCodecs.CommentsSupported first 
              
   // Create the comments 
   RasterCollection<RasterCommentMetadata> comments = new RasterCollection<RasterCommentMetadata>(); 
              
   RasterCommentMetadata comment = new RasterCommentMetadata(RasterCommentMetadataType.Copyright, null); 
   comment.FromAscii("Copyright (c) My Company"); 
   comments.Add(comment); 
              
   comment = new RasterCommentMetadata(RasterCommentMetadataType.Description, null); 
   comment.FromAscii("My description"); 
   comments.Add(comment); 
              
   // Write them to the file 
   rasterCodecsInstance.WriteComments(fileName, 1, comments); 
} 

private static RasterImage LoadImageWithTags(RasterCodecs rasterCodecsInstance, string fileName) 
{ 
   // Setup the markers to be read when the image is loaded 
   rasterCodecsInstance.Options.Load.Markers = false; 
   rasterCodecsInstance.Options.Load.Tags = true; 
   rasterCodecsInstance.Options.Load.Comments = false; 
   rasterCodecsInstance.Options.Load.GeoKeys = false; 
              
   // Load and return the image 
   RasterImage image = rasterCodecsInstance.Load(fileName, 0, CodecsLoadByteOrder.BgrOrGray, 1, 1); 
              
   // Trace information: 
   System.Diagnostics.Trace.WriteLine("Format is: " + image.OriginalFormat); 
   System.Diagnostics.Trace.WriteLine("Number of tags loaded" + image.Tags.Count); 
              
   return image; 
} 

private static void LoadUpdateSaveImageMetadata(RasterCodecs rasterCodecsInstance, string fileName) 
{ 
   // 1. Setup the markers to be read when the image is loaded 
   rasterCodecsInstance.Options.Load.Markers = false; 
   rasterCodecsInstance.Options.Load.Tags = true; 
   rasterCodecsInstance.Options.Load.Comments = true; 
   rasterCodecsInstance.Options.Load.GeoKeys = false; 
              
   // 2. Load the image 
   using(RasterImage image = rasterCodecsInstance.Load(fileName, 0, CodecsLoadByteOrder.BgrOrGray, 1, 1)) 
   { 
      // 3. Add the string "LEADTOOLS" to the image 
      // Note: If you do not require adding the string to the image, then 
      // skip to 4. Update te metadata 
      IntPtr hdc = image.CreateLeadDC(); 
      using(Graphics g = Graphics.FromHdc(hdc)) 
      using(Font f = new Font(FontFamily.GenericSansSerif, 40, FontStyle.Bold)) 
      using(Brush b = new SolidBrush(Color.FromArgb(128, Color.Black))) 
      { 
         g.DrawString("LEADTOOLS", f, b, 0, 0); 
      } 
      RasterImage.DeleteLeadDC(hdc); 
              
      // 4. Update the metadata 
      // Since we set the CodecsLoadOptions.Tags and CodecsLoadOptions.Comments 
      // to true, the RasterCodecs object will read all the tags and comments from 
      // the file and store them in the RasterImage.Tags and RasterImage.Comments 
      // collections respectively. 
              
      // Find the EXIF title tag 
      const int exifImageTitleTagId = 0x010E; 
      RasterTagMetadata imageTitleTag = null; 
      foreach(RasterTagMetadata tag in image.Tags) 
      { 
         if(tag.Id == exifImageTitleTagId) 
         { 
            imageTitleTag = tag; 
            break; 
         } 
      } 
              
      // If the tag was found, update it 
      if(imageTitleTag != null) 
      { 
         string title = imageTitleTag.ToAscii(); 
         title = "LEADTOOLS - " + title; 
         imageTitleTag.FromAscii(title); 
      } 
              
      // Find the description comment field 
      RasterCommentMetadata descriptionComment = null; 
      foreach(RasterCommentMetadata comment in image.Comments) 
      { 
         if(comment.Type == RasterCommentMetadataType.Description) 
         { 
            descriptionComment = comment; 
            break; 
         } 
      } 
              
      // If the comment was found, update it 
      if(descriptionComment != null) 
      { 
         string title = descriptionComment.ToAscii(); 
         title = "LEADTOOLS - " + title; 
         descriptionComment.FromAscii(title); 
      } 
              
      // As well as updating the existing metadata, you can 
      // add and remove as many tags and comments from 
      // the collections here 
              
      // 5. Setup the markers to be written when the image is saved 
      rasterCodecsInstance.Options.Save.Markers = false; 
      rasterCodecsInstance.Options.Save.Tags = true; 
      rasterCodecsInstance.Options.Save.Comments = true; 
      rasterCodecsInstance.Options.Save.GeoKeys = false; 
              
      // Save it back 
      // Since we set the CodecsSaveOptions.Tags and CodecsSaveOptions.Comments 
      // to true, the RasterCodecs object will write all the tags and comments from 
      // RasterImage.Tags and RasterImage.Comments collections respectively and 
      // save them to the files 
      rasterCodecsInstance.Save(image, fileName, image.OriginalFormat, 0); 
   } 
}