RasterMarkerMetadata Class

Extends the RasterMetadata class to provide functionality for dealing with marker metadata stored within various image file formats.

Object Model

Syntax

C#
Visual Basic
WinRT C#
Objective-C
Java
WinRT JavaScript
C++

[SerializableAttribute()]
public class RasterMarkerMetadata : RasterMetadata

'Declaration
 
<SerializableAttribute()>
Public Class RasterMarkerMetadata 
   Inherits RasterMetadata

'Usage
 
Dim instance As RasterMarkerMetadata

public sealed class RasterMarkerMetadata : RasterMetadata

@interface LTRasterMarkerMetadata : LTRasterMetadata

public class RasterMarkerMetadata extends RasterMetadata implements Serializable

function Leadtools.RasterMarkerMetadata()

[SerializableAttribute()]
public ref class RasterMarkerMetadata : public RasterMetadata

Remarks

JPEG files contain metadata information in user-defined markers.

The user-defined markers are in the range 0xE0 to 0xFE. These markers can have a maximum size of 0xFFFD, or 65533 bytes.

The markers below 0xE0 are reserved for the encoding of the image and inserting a reserved marker can make a file invalid. Therefore, you should not use reserved markers unless you are well acquainted with markers and image encoding in JPEG files.

TIFF files do not contain markers, however, LEADTOOLS provides a "workaround" for transferring Exif comments from JPEG files to TIFF files, and vice versa. The Exif metadata information from a TIFF file will be loaded as an APP1 marker. Therefore, you can load Exif metadata from an uncompressed file and store it in a compressed Exif file.

You can also take metadata information from a compressed Exif file and store it in an uncompressed Exif file. Please note however, that some information cannot be stored inside uncompressed Exif files. For example, audio data is stored in APP2 markers and there is no built-in support for saving APP2 markers in TIFF files. However, you can still save the audio data yourself, using a custom tag.

Example

C#
Visual Basic
WinRT C#
WinRT JavaScript
Silverlight C#
Silverlight VB

Copy Code

Imports Leadtools
  Imports Leadtools.Codecs

  Public Sub RasterMarkerMetadataExample()
   Dim codecs As RasterCodecs = New RasterCodecs()
   codecs.ThrowExceptionsOnInvalidImages = True

   Dim srcFileName As String = Path.Combine(LEAD_VARS.ImagesDir, "Image1.cmp")
   Dim destFileName As String = Path.Combine(LEAD_VARS.ImagesDir, "Image1_markers.tif")

   ' Load the image
   Dim image As RasterImage = codecs.Load(srcFileName)
   codecs.Save(image, destFileName, RasterImageFormat.ExifJpeg, 24)

   image.Dispose()

   ' write a marker to the file
   Dim markerWrite As RasterMarkerMetadata = New RasterMarkerMetadata()
   Dim data As Byte() = New Byte(99) {}
   Dim i As Integer = 0
   Do While i < data.Length
      data(i) = CByte(i + 1)
      i += 1
   Loop
   markerWrite.Id = &HE0
   markerWrite.SetData(data)

   Console.WriteLine("Writing the marker")
   codecs.WriteMarker(destFileName, 1, markerWrite)

   ' read the markers from the file and check for ours
   Dim markers As RasterCollection(Of RasterMarkerMetadata) = codecs.ReadMarkers(destFileName)
   Dim markerRead As RasterMarkerMetadata = Nothing
   i = 0
   Do While i < markers.Count AndAlso markerRead Is Nothing
      If markers(i).Id = markerWrite.Id Then
         markerRead = markers(i)
      End If
      i += 1
   Loop

   Debug.Assert(markerRead.Id = markerWrite.Id)
   Dim dataRead As Byte() = markerRead.GetData()
   Dim dataWrite As Byte() = markerWrite.GetData()
   Debug.Assert(dataRead.Length = dataWrite.Length)
   i = 0
   Do While i < dataRead.Length
      Debug.Assert(dataRead(i) = dataWrite(i))
      i += 1
   Loop
End Sub

  Public NotInheritable Class LEAD_VARS
  Public Const ImagesDir As String = "C:\Users\Public\Documents\LEADTOOLS Images"
  End Class

using Leadtools;
using Leadtools.Codecs;

      
public void RasterMarkerMetadataExample()
{
   RasterCodecs codecs = new RasterCodecs();
   codecs.ThrowExceptionsOnInvalidImages = true;
   string srcFileName = Path.Combine(ImagesPath.Path,"Image1.cmp");
   string destFileName = Path.Combine(ImagesPath.Path, "Image1_markers.tif");

   // Load the image
   RasterImage image = codecs.Load(srcFileName);
   codecs.Save(image, destFileName, RasterImageFormat.ExifJpeg, 24);

   image.Dispose();

   // write a marker to the file
   RasterMarkerMetadata markerWrite = new RasterMarkerMetadata();
   byte[] data = new byte[100];
   for(int i=0; i < data.Length; i++ )
      data[i] = (byte)(i + 1);
   markerWrite.Id = 0xE0;
   markerWrite.SetData(data);

   Console.WriteLine("Writing the marker");
   codecs.WriteMarker(destFileName, 1, markerWrite);

   // read the markers from the file and check for ours
   RasterCollection<RasterMarkerMetadata> markers = codecs.ReadMarkers(destFileName);
   RasterMarkerMetadata markerRead = null;
   for(int i = 0; i < markers.Count && markerRead == null; i++)
   {
      if(markers[i].Id == markerWrite.Id)
         markerRead = markers[i];
   }

   Assert.IsTrue(markerRead.Id == markerWrite.Id);
   byte[] dataRead = markerRead.GetData();
   byte[] dataWrite = markerWrite.GetData();
   Assert.IsTrue(dataRead.Length == dataWrite.Length);
   for(int i = 0; i < dataRead.Length; i++)
      Assert.IsTrue(dataRead[i] == dataWrite[i]);

   codecs.Dispose();
}

RasterMarkerMetadataExamples.prototype.RasterMarkerMetadataExample = function ( )
{
    Tools.SetLicense ( ) ;
    with ( Leadtools ) { with ( Leadtools.Codecs ) { 
        var codecs = new RasterCodecs();
        codecs.throwExceptionsOnInvalidImages = true;

        var srcFileName = "Assets\\Image1.cmp";
        var destFileName = "Image1_markers.tif";
        var image;
        var saveFile;
        var markerWrite = new RasterMarkerMetadata();
        // Load the image
        return Tools.AppInstallFolder().getFileAsync(srcFileName).then ( function ( loadFile ) {
            return codecs.loadAsync(LeadStreamFactory.create(loadFile))})
            .then ( function ( img ) {
                image = img;
                //Save the file as exif
                return Tools.AppLocalFolder().createFileAsync(destFileName)})
            .then(function (sfile) {
                saveFile = sfile;
                return codecs.saveAsync(image, LeadStreamFactory.create(saveFile), RasterImageFormat.exifJpeg, 24)})
            .then ( function ( ) {

                image.close();

                // write a marker to the file
                
                var data = new Array(100);
                for(var  i=0; i < data.length; i++ )
                    data[i] = (i + 1);
                markerWrite.id = 0xE0;
                markerWrite.setData(data);

                console.info("Writing the marker");
                return codecs.writeMarkerAsync(LeadStreamFactory.create(saveFile), 1, markerWrite)})
            .then ( function ( ) {
         
                // read the markers from the file and check for ours
                return codecs.readMarkersAsync(LeadStreamFactory.create(saveFile))})
            .then ( function ( markers ) {
                var markerRead = null;
                for(var i = 0; i < markers.size && markerRead == null; i++)
                {
                    if(markers[i].id == markerWrite.id)
                        markerRead = markers[i];
                }

                console.assert(markerRead.id == markerWrite.id, "markerRead.id == markerWrite.id");
                var dataRead = markerRead.getData();
                var dataWrite = markerWrite.getData();
                console.assert(dataRead.length == dataWrite.length, "dataRead.length == dataWrite.length");

                for(var i = 0; i < dataRead.length; i++)
                    console.assert (dataRead[i] == dataWrite[i], "dataRead[i] == dataWrite[i]");
            });
    }
    }
}

using Leadtools;
using Leadtools.Codecs;

      
public async Task RasterMarkerMetadataExample()
{
   RasterCodecs codecs = new RasterCodecs();
   codecs.ThrowExceptionsOnInvalidImages = true;
   string srcFileName = @"Assets\Image1.cmp";
   string destFileName = @"Image1_markers.tif";

   // Load the image
   StorageFile loadFile = await Tools.AppInstallFolder.GetFileAsync(srcFileName);
   RasterImage image = await codecs.LoadAsync(LeadStreamFactory.Create(loadFile));

   //Save the file as exif
   StorageFile saveFile = await Tools.AppLocalFolder.CreateFileAsync(destFileName);
   await codecs.SaveAsync(image, LeadStreamFactory.Create(saveFile), RasterImageFormat.ExifJpeg, 24);

   image.Dispose();

   // write a marker to the file
   RasterMarkerMetadata markerWrite = new RasterMarkerMetadata();
   byte[] data = new byte[100];
   for(int i=0; i < data.Length; i++ )
      data[i] = (byte)(i + 1);
   markerWrite.Id = 0xE0;
   markerWrite.SetData(data);

   Debug.WriteLine("Writing the marker");
   await codecs.WriteMarkerAsync(LeadStreamFactory.Create(saveFile), 1, markerWrite);

   // read the markers from the file and check for ours
   IList<RasterMarkerMetadata> markers = await codecs.ReadMarkersAsync(LeadStreamFactory.Create(saveFile));
   RasterMarkerMetadata markerRead = null;
   for(int i = 0; i < markers.Count && markerRead == null; i++)
   {
      if(markers[i].Id == markerWrite.Id)
         markerRead = markers[i];
   }

   Assert.IsTrue(markerRead.Id == markerWrite.Id);
   byte[] dataRead = markerRead.GetData();
   byte[] dataWrite = markerWrite.GetData();
   Assert.IsTrue(dataRead.Length == dataWrite.Length);
   for(int i = 0; i < dataRead.Length; i++)
      Assert.IsTrue(dataRead[i] == dataWrite[i]);
}

using Leadtools;
using Leadtools.Codecs;
using Leadtools.Examples;
using Leadtools.ImageProcessing;

public void RasterMarkerMetadataExample(RasterImage image, Stream destStream)
{
   RasterCodecs codecs = new RasterCodecs();
   codecs.Save(image, destStream, RasterImageFormat.ExifJpeg, 24);
   image.Dispose();

   // write a marker to the file
   RasterMarkerMetadata markerWrite = new RasterMarkerMetadata();
   byte[] data = new byte[100];
   for(int i=0; i < data.Length; i++ )
      data[i] = (byte)(i + 1);
   markerWrite.Id = 0xE0;
   markerWrite.SetData(data);

   Console.WriteLine("Writing the marker");
   codecs.WriteMarker(destStream, 1, markerWrite);

   // read the markers from the file and check for ours
   RasterCollection<RasterMarkerMetadata> markers = codecs.ReadMarkers(destStream);
   RasterMarkerMetadata markerRead = null;
   for(int i = 0; i < markers.Count && markerRead == null; i++)
   {
      if(markers[i].Id == markerWrite.Id)
         markerRead = markers[i];
   }

   Debug.Assert(markerRead.Id == markerWrite.Id);
   byte[] dataRead = markerRead.GetData();
   byte[] dataWrite = markerWrite.GetData();
   Debug.Assert(dataRead.Length == dataWrite.Length);
   for(int i = 0; i < dataRead.Length; i++)
      Debug.Assert(dataRead[i] == dataWrite[i]);
}

Imports Leadtools
Imports Leadtools.Codecs
Imports Leadtools.ImageProcessing

Public Sub RasterMarkerMetadataExample(ByVal image As RasterImage, ByVal destStream As Stream)
   Dim codecs As RasterCodecs = New RasterCodecs()
   codecs.Save(image, destStream, RasterImageFormat.ExifJpeg, 24)
   image.Dispose()

   ' write a marker to the file
   Dim markerWrite As RasterMarkerMetadata = New RasterMarkerMetadata()
   Dim data As Byte() = New Byte(99){}
   Dim i As Integer=0
   Do While i < data.Length
      data(i) = CByte(i + 1)
      i += 1
   Loop
   markerWrite.Id = &HE0
   markerWrite.SetData(data)

   Console.WriteLine("Writing the marker")
   codecs.WriteMarker(destStream, 1, markerWrite)

   ' read the markers from the file and check for ours
   Dim markers As RasterCollection(Of RasterMarkerMetadata) = codecs.ReadMarkers(destStream)
   Dim markerRead As RasterMarkerMetadata = Nothing
   i = 0
   Do While i < markers.Count AndAlso markerRead Is Nothing
      If markers(i).Id = markerWrite.Id Then
         markerRead = markers(i)
      End If
      i += 1
   Loop

   Debug.Assert(markerRead.Id = markerWrite.Id)
   Dim dataRead As Byte() = markerRead.GetData()
   Dim dataWrite As Byte() = markerWrite.GetData()
   Debug.Assert(dataRead.Length = dataWrite.Length)
   i = 0
   Do While i < dataRead.Length
      Debug.Assert(dataRead(i) = dataWrite(i))
      i += 1
   Loop
End Sub

Requirements

Target Platforms

Reference

RasterMarkerMetadata Members
Leadtools Namespace