RasterCommentMetadata Class

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

Object Model

Syntax

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

[SerializableAttribute()]
public class RasterCommentMetadata : RasterMetadata

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

'Usage
 
Dim instance As RasterCommentMetadata

public sealed class RasterCommentMetadata : RasterMetadata

@interface LTRasterCommentMetadata : LTRasterMetadata

public class RasterCommentMetadata extends RasterMetadata implements Serializable

function Leadtools.RasterCommentMetadata()

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

Remarks

The TIFF file formats support a number of comments that are saved and loaded using predefined tags.

If the comments do not meet your needs, you can define your own tag for saving additional non-raster data in a TIFF file. For example, you may want to define a tag to save annotations.

The TIFF 6.0 Specification sets aside a range of private tags that developers can define. To avoid conflicts with files created by other developers, you can register your tag by contacting Adobe Developer Relations. The E-Mail address posted on The Unofficial TIFF Home Page is gapdevsup@adobe.com.

Some restrictions apply to this function if you use an IFD to indicate to which page to write the metadata. See the Loading And Saving Large TIFF Files topic for more information.

Example

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

Copy Code

Imports Leadtools
  Imports Leadtools.Codecs

  Public Sub RasterCommentMetadataExample()
   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_comments.tif")

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

   image.Dispose()

   ' Write some comments to the existing tif file
   Dim comment As RasterCommentMetadata = New RasterCommentMetadata()
   comment.Type = RasterCommentMetadataType.Artist
   Dim artistNameWrite As String = "Artist name"
   comment.FromAscii(artistNameWrite)
   Console.WriteLine("Writing Artist")
   codecs.WriteComment(destFileName, 1, comment)

   comment.Type = RasterCommentMetadataType.GpsLatitude
   Dim rationalsWrite As RasterMetadataRational() = New RasterMetadataRational(2) {}
   Dim i As Integer = 0
   Do While i < rationalsWrite.Length
      rationalsWrite(i) = New RasterMetadataRational(i + 3, i + 2)
      i += 1
   Loop

   comment.FromRational(rationalsWrite)
   Console.WriteLine("Writing GpsLatitude")
   codecs.WriteComment(destFileName, 1, comment)

   ' Now read the comments from the tif file

   ' read ASCII
   comment = codecs.ReadComment(destFileName, 1, RasterCommentMetadataType.Artist)
   Dim artistNameRead As String = comment.ToAscii()
   Console.WriteLine("Artist: {0}", artistNameRead)
   Debug.Assert(artistNameRead = artistNameWrite)

   ' read rationals
   comment = codecs.ReadComment(destFileName, 1, RasterCommentMetadataType.GpsLatitude)
   Dim rationalsRead As RasterMetadataRational() = comment.ToRational()

   Dim size As Integer = rationalsRead.Length
   Console.WriteLine("GpsLatitude: size = {0} ", size)
   i = 0
   Do While i < size
      Console.WriteLine("{0}/{1}", rationalsRead(i).Numerator, rationalsRead(i).Denominator)
      i += 1
   Loop

   Debug.Assert(rationalsRead.Length = rationalsWrite.Length)
   i = 0
   Do While i < rationalsRead.Length
      Debug.Assert(rationalsRead(i).Numerator = rationalsWrite(i).Numerator)
      Debug.Assert(rationalsRead(i).Denominator = rationalsWrite(i).Denominator)
      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 RasterCommentMetadataExample()
{
   RasterCodecs codecs = new RasterCodecs();
   codecs.ThrowExceptionsOnInvalidImages = true;
   string srcFileName = Path.Combine(ImagesPath.Path, "Image1.cmp");
   string destFileName = Path.Combine(ImagesPath.Path, "Image1_comments.tif");

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

   image.Dispose();

   // Write some comments to the existing tif file
   RasterCommentMetadata comment = new RasterCommentMetadata();
   comment.Type = RasterCommentMetadataType.Artist;
   string artistNameWrite = "Artist name";
   comment.FromAscii(artistNameWrite);
   Console.WriteLine("Writing Artist");
   codecs.WriteComment(destFileName, 1, comment);

   comment.Type = RasterCommentMetadataType.GpsLatitude;
   RasterMetadataRational[] rationalsWrite = new RasterMetadataRational[3];
   for(int i = 0; i < rationalsWrite.Length; i++)
      rationalsWrite[i] = new RasterMetadataRational(i + 3, i + 2);

   comment.FromRational(rationalsWrite);
   Console.WriteLine("Writing GpsLatitude");
   codecs.WriteComment(destFileName, 1, comment);

   // Now read the comments from the tif file

   // read ASCII
   comment = codecs.ReadComment(destFileName, 1, RasterCommentMetadataType.Artist);
   string artistNameRead = comment.ToAscii();
   Console.WriteLine("Artist: {0}", artistNameRead);
   Assert.IsTrue(artistNameRead == artistNameWrite);

   // read rationals
   comment = codecs.ReadComment(destFileName, 1, RasterCommentMetadataType.GpsLatitude);
   RasterMetadataRational[] rationalsRead = comment.ToRational();

   int size = rationalsRead.Length;
   Console.WriteLine("GpsLatitude: size = {0} ", size);
   for(int i = 0; i < size; i++)
      Console.WriteLine("{0}/{1}", rationalsRead[i].Numerator, rationalsRead[i].Denominator);

   Assert.IsTrue(rationalsRead.Length == rationalsWrite.Length);
   for(int i = 0; i < rationalsRead.Length; i++)
   {
      Assert.IsTrue(rationalsRead[i].Numerator == rationalsWrite[i].Numerator);
      Assert.IsTrue(rationalsRead[i].Denominator == rationalsWrite[i].Denominator);
   }
}

RasterCommentMetadataExamples.prototype.RasterCommentMetadataExample = function () {
    Tools.SetLicense();
    with (Leadtools) {
        with (Leadtools.Codecs) {
            with (Leadtools.ImageProcessing) {
                var codecs = new RasterCodecs();

                codecs.throwExceptionsOnInvalidImages = true;

                var srcFileName = "Assets\\Image1.cmp";
                var destFileName = "Image1_comments.tif";
                var image;
                var comment;
                var saveFile;
                var artistNameWrite = "Artist name";
                var rationalsWrite = new Array(3);
                // Load the image
                return Tools.AppInstallFolder().getFileAsync(srcFileName).then(function (loadFile) {
                    return codecs.loadAsync(LeadStreamFactory.create(loadFile))
                })
                    .then(function (img) {
                        image = img;

                        //Save as tif
                        return Tools.AppLocalFolder().createFileAsync(destFileName)
                    })
                    .then(function (sveFile) {
                        saveFile = sveFile;
                        return codecs.saveAsync(image, LeadStreamFactory.create(saveFile), RasterImageFormat.tif, 24)
                    })
                    .then(function () {

                        image.close();

                        // Write some comments to the existing tif file
                        comment = new RasterCommentMetadata();
                        comment.type = RasterCommentMetadataType.artist;
                        
                        comment.fromAscii(artistNameWrite);
                        console.info("Writing Artist");
                        return codecs.writeCommentAsync(LeadStreamFactory.create(saveFile), 1, comment)
                    })
                    .then(function () {

                        comment = new RasterCommentMetadata();
                        comment.type = RasterCommentMetadataType.gpsLatitude;
                        
                        for (var i = 0; i < rationalsWrite.length; i++)
                            rationalsWrite[i] = RasterMetadataRationalHelper.create(i + 3, i + 2);

                        comment.fromRational(rationalsWrite);
                        console.info("Writing GpsLatitude");
                        return codecs.writeCommentAsync(LeadStreamFactory.create(saveFile), 1, comment)
                    })
                    .then(function () {

                        // Now read the comments from the tif file

                        // read ASCII
                        return codecs.readCommentAsync(LeadStreamFactory.create(saveFile), 1, RasterCommentMetadataType.artist)
                    })
                    .then(function (cmnt) {
                        comment = cmnt;

                        var artistNameRead = comment.toAscii();
                        console.info("Artist: ", artistNameRead);
                        console.assert(artistNameRead == artistNameWrite, "artistNameRead == artistNameWrite");

                        // read rationals
                        return codecs.readCommentAsync(LeadStreamFactory.create(saveFile), 1, RasterCommentMetadataType.gpsLatitude)})
                    .then(function (cmnt1) {
                        comment = cmnt1;
                        var rationalsRead = comment.toRational();

                        var size = rationalsRead.length;
                        console.info("GpsLatitude: size = ", size);
                        for (var i = 0; i < size; i++)
                            console.info(rationalsRead[i].numerator + "/" + rationalsRead[i].denominator);

                        console.assert(rationalsRead.length == rationalsWrite.length);

                        for (var i = 0; i < rationalsRead.length; i++) {
                            console.assert(rationalsRead[i].numerator === rationalsWrite[i].numerator,"rationalsRead[i].numerator === rationalsWrite[i].numerator");
                            console.assert(rationalsRead[i].denominator == rationalsWrite[i].denominator, "rationalsRead[i].denominator == rationalsWrite[i].denominator");
                        }
                    });
            }
        }
    }
}

using Leadtools;
using Leadtools.Codecs;

        
public async Task RasterCommentMetadataExample()
{
    RasterCodecs codecs = new RasterCodecs();
    codecs.ThrowExceptionsOnInvalidImages = true;
    string srcFileName = @"Assets\Image1.cmp";
    string destFileName = @"Image1_comments.tif";

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

    //Save as tif
    StorageFile saveFile = await Tools.AppLocalFolder.CreateFileAsync(destFileName);
    ILeadStream saveStream = LeadStreamFactory.Create(saveFile);
    await codecs.SaveAsync(image, saveStream, RasterImageFormat.Tif, 24);

    image.Dispose();

    // Write some comments to the existing tif file
    RasterCommentMetadata comment = new RasterCommentMetadata();
    comment.Type = RasterCommentMetadataType.Artist;
    string artistNameWrite = "Artist name";
    comment.FromAscii(artistNameWrite);
    Debug.WriteLine("Writing Artist");
    await codecs.WriteCommentAsync(saveStream, 1, comment);

    comment.Type = RasterCommentMetadataType.GpsLatitude;
    RasterMetadataRational[] rationalsWrite = new RasterMetadataRational[3];
    for (int i = 0; i < rationalsWrite.Length; i++)
        rationalsWrite[i] = RasterMetadataRationalHelper.Create(i + 3, i + 2);

    comment.FromRational(rationalsWrite);
    Debug.WriteLine("Writing GpsLatitude");
    await codecs.WriteCommentAsync(LeadStreamFactory.Create(saveFile), 1, comment);

    // Now read the comments from the tif file

    // read ASCII
    comment = await codecs.ReadCommentAsync(saveStream, 1, RasterCommentMetadataType.Artist);
    string artistNameRead = comment.ToAscii();
    Debug.WriteLine("Artist: {0}", artistNameRead);
    Assert.IsTrue(artistNameRead == artistNameWrite);

    // read rationals
    comment = await codecs.ReadCommentAsync(saveStream, 1, RasterCommentMetadataType.GpsLatitude);

    RasterMetadataRational[] rationalsRead = comment.ToRational();

    int size = rationalsRead.Length;
    Debug.WriteLine("GpsLatitude: size = {0} ", size);
    for (int i = 0; i < size; i++)
        Debug.WriteLine("{0}/{1}", rationalsRead[i].Numerator, rationalsRead[i].Denominator);

    Assert.IsTrue(rationalsRead.Length == rationalsWrite.Length);
    for (int i = 0; i < rationalsRead.Length; i++)
    {
        Assert.IsTrue(rationalsRead[i].Numerator == rationalsWrite[i].Numerator);
        Assert.IsTrue(rationalsRead[i].Denominator == rationalsWrite[i].Denominator);
    }
}

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

public void RasterCommentMetadataExample(RasterImage image, Stream destStream)
{
   RasterCodecs codecs = new RasterCodecs();
   codecs.Save(image, destStream, RasterImageFormat.Tif, 24);
   image.Dispose();
   // Write some comments to the existing tif file
   RasterCommentMetadata comment = new RasterCommentMetadata();
   comment.Type = RasterCommentMetadataType.Artist;
   string artistNameWrite = "Artist name";
   comment.FromAscii(artistNameWrite);
   Debug.WriteLine("Writing Artist");
   codecs.WriteComment(destStream, 1, comment);

   comment.Type = RasterCommentMetadataType.GpsLatitude;
   RasterMetadataRational[] rationalsWrite = new RasterMetadataRational[3];
   for(int i = 0; i < rationalsWrite.Length; i++)
      rationalsWrite[i] = new RasterMetadataRational(i + 3, i + 2);

   comment.FromRational(rationalsWrite);
   Debug.WriteLine("Writing GpsLatitude");
   codecs.WriteComment(destStream, 1, comment);

   // Now read the comments from the tif file

   // read ASCII
   comment = codecs.ReadComment(destStream, 1, RasterCommentMetadataType.Artist);
   string artistNameRead = comment.ToAscii();
   Debug.WriteLine("Artist: {0}", artistNameRead);
   Debug.Assert(artistNameRead == artistNameWrite);

   // read rationals
   comment = codecs.ReadComment(destStream, 1, RasterCommentMetadataType.GpsLatitude);
   RasterMetadataRational[] rationalsRead = comment.ToRational();

   int size = rationalsRead.Length;
   Debug.WriteLine("GpsLatitude: size = {0} ", size);
   for(int i = 0; i < size; i++)
      Debug.WriteLine("{0}/{1}", rationalsRead[i].Numerator, rationalsRead[i].Denominator);

   Debug.Assert(rationalsRead.Length == rationalsWrite.Length);
   for(int i = 0; i < rationalsRead.Length; i++)
   {
      Debug.Assert(rationalsRead[i].Numerator == rationalsWrite[i].Numerator);
      Debug.Assert(rationalsRead[i].Denominator == rationalsWrite[i].Denominator);
   }
}

Imports Leadtools
Imports Leadtools.Codecs
Imports Leadtools.ImageProcessing

Public Sub RasterCommentMetadataExample(ByVal image As RasterImage, ByVal destStream As Stream)
   Dim codecs As RasterCodecs = New RasterCodecs()
   codecs.Save(image, destStream, RasterImageFormat.Tif, 24)
   image.Dispose()
   ' Write some comments to the existing tif file
   Dim comment As RasterCommentMetadata = New RasterCommentMetadata()
   comment.Type = RasterCommentMetadataType.Artist
   Dim artistNameWrite As String = "Artist name"
   comment.FromAscii(artistNameWrite)
   Debug.WriteLine("Writing Artist")
   codecs.WriteComment(destStream, 1, comment)

   comment.Type = RasterCommentMetadataType.GpsLatitude
   Dim rationalsWrite As RasterMetadataRational() = New RasterMetadataRational(2){}
   Dim i As Integer = 0
   Do While i < rationalsWrite.Length
      rationalsWrite(i) = New RasterMetadataRational(i + 3, i + 2)
      i += 1
   Loop

   comment.FromRational(rationalsWrite)
   Debug.WriteLine("Writing GpsLatitude")
   codecs.WriteComment(destStream, 1, comment)

   ' Now read the comments from the tif file

   ' read ASCII
   comment = codecs.ReadComment(destStream, 1, RasterCommentMetadataType.Artist)
   Dim artistNameRead As String = comment.ToAscii()
   Debug.WriteLine("Artist: {0}", artistNameRead)
   Debug.Assert(artistNameRead = artistNameWrite)

   ' read rationals
   comment = codecs.ReadComment(destStream, 1, RasterCommentMetadataType.GpsLatitude)
   Dim rationalsRead As RasterMetadataRational() = comment.ToRational()

   Dim size As Integer = rationalsRead.Length
   Debug.WriteLine("GpsLatitude: size = {0} ", size)
   i = 0
   Do While i < size
      Debug.WriteLine("{0}/{1}", rationalsRead(i).Numerator, rationalsRead(i).Denominator)
      i += 1
   Loop

   Debug.Assert(rationalsRead.Length = rationalsWrite.Length)
   i = 0
   Do While i < rationalsRead.Length
      Debug.Assert(rationalsRead(i).Numerator = rationalsWrite(i).Numerator)
      Debug.Assert(rationalsRead(i).Denominator = rationalsWrite(i).Denominator)
      i += 1
   Loop
End Sub

Requirements

Target Platforms

Reference

RasterCommentMetadata Members
Leadtools Namespace