Image metadata

In This Topic

Image metadata store data about image and define such aspects as keywords, GPS location, camera information and more.

The SDK provides the ability to get metadata from image file, edit existing and add new metadata. All these operations are performed without loading of image from file.

The SDK allows to work with the following types of metadata:

TIFF metadata (TIFF)
EXIF metadata (TIFF, JPEG, DNG, NRW, CR2, NEF)
GPS metadata (TIFF, JPEG, DNG, NRW, CR2, NEF)
Annotations in VintasoftBinary format (TIFF, JPEG, PNG, PDF)
Annotations in VintasoftXmp format (TIFF, JPEG, PDF)
Annotations in WANG format (TIFF)
Text-comments (PNG, GIF)
Image thumbnail (JPEG, PDF)
RAW camera metadata (DNG, NRW, CR2, CRW, NEF)
DICOM metadata (DCM, DIC, ACR)

There are 3 techniques of accessing image metadata:

Access to the image metadata using the metadata tree, which can be get from VintasoftImage object. This way provides access to the metadata of all image formats supported by SDK (JPEG, TIFF, PDF, etc).
Access to the image metadata using properties and methods of class, which is derived from ImageFileBase<T> class. This way provides access to the metadata of all image formats (JPEG, TIFF, etc) supported by SDK, except PDF.
Access to the PDF document metadata using properties and methods of PdfDocument object.

Access to the metadata of VintasoftImage object

VintasoftImageMetadata class provides simplified access to the image metadata in case when work with image is performed using VintasoftImage class. Access to an instance of VintasoftImageMetadata class may be obtained using VintasoftImage.Metadata property.

VintasoftImageMetadata class provides access to:

"raw" image annotations
tree of image metadata

Here is an example that shows how to obtain information about annotation packets, which are stored in JPEG file metadata:

VB.NET

' The project, which uses this code, must have references to the following assemblies:
' - Vintasoft.Imaging

Public Sub PrintInfoAboutJpegFileAnnotations(filename As String)
        ' create an instance of VintasoftImage class
        Using jpegImage As New Vintasoft.Imaging.VintasoftImage(filename)
                ' get reference to a metadata tree of JPEG page
                Dim jpegPageMetadata As Vintasoft.Imaging.Metadata.MetadataNode = jpegImage.Metadata.MetadataTree

                ' create an instance of MetadataTreeHelper class
                Dim metadataTreeHelper As New Vintasoft.Imaging.Metadata.MetadataTreeHelper(jpegPageMetadata)

                '
                If Not metadataTreeHelper.HasVintasoftBinaryAnnotations AndAlso Not metadataTreeHelper.HasVintasoftXmpAnnotations Then
                        System.Console.Write(String.Format("File '{0}' does not have annotations.", filename))
                Else
                        If metadataTreeHelper.HasVintasoftBinaryAnnotations Then
                                System.Console.Write(String.Format("File '{0}' has VintasoftBinary annotations.", filename))
                        End If

                        If metadataTreeHelper.HasVintasoftXmpAnnotations Then
                                System.Console.Write(String.Format("File '{0}' has VintasoftXmp annotations.", filename))
                        End If
                End If
        End Using
End Sub

// The project, which uses this code, must have references to the following assemblies:
// - Vintasoft.Imaging

public void PrintInfoAboutJpegFileAnnotations(string filename)
{
    // create an instance of VintasoftImage class
    using (Vintasoft.Imaging.VintasoftImage jpegImage = new Vintasoft.Imaging.VintasoftImage(filename))
    {
        // get reference to a metadata tree of JPEG page
        Vintasoft.Imaging.Metadata.MetadataNode jpegPageMetadata = jpegImage.Metadata.MetadataTree;

        // create an instance of MetadataTreeHelper class
        Vintasoft.Imaging.Metadata.MetadataTreeHelper metadataTreeHelper = 
            new Vintasoft.Imaging.Metadata.MetadataTreeHelper(jpegPageMetadata);

        //
        if (!metadataTreeHelper.HasVintasoftBinaryAnnotations &&
            !metadataTreeHelper.HasVintasoftXmpAnnotations)
            System.Console.Write(string.Format("File '{0}' does not have annotations.", filename));
        else
        {
            if (metadataTreeHelper.HasVintasoftBinaryAnnotations)
                System.Console.Write(string.Format("File '{0}' has VintasoftBinary annotations.", filename));

            if (metadataTreeHelper.HasVintasoftXmpAnnotations)
                System.Console.Write(string.Format("File '{0}' has VintasoftXmp annotations.", filename));
        }
    }
}

The metadata tree represents the image metadata as a tree structure. Access to the metadata tree can be obtained using VintasoftImageMetadata.MetadataTree property.
The metadata tree root node represents a page of image file. Each tree node may contain information about image metadata and child nodes.

Here is an example that shows how to obtain information about TIFF tags of TIFF file:

VB.NET

' The project, which uses this code, must have references to the following assemblies:
' - Vintasoft.Imaging

Public Sub PrintInfoAboutTiffFile(filename As String)
        ' create an image collection
        Dim images As New Vintasoft.Imaging.ImageCollection()
        ' add TIFF file to a collection
        images.Add(filename)

        For i As Integer = 0 To images.Count - 1
                System.Console.WriteLine(String.Format("Page {0}", i))

                ' get reference to a metadata tree of TIFF page
                Dim tiffPageMetadata As Vintasoft.Imaging.Metadata.MetadataNode = images(i).Metadata.MetadataTree

                ' search for tree node that contains information about TIFF IFD
                Dim tiffIfdMetadata As Vintasoft.Imaging.Metadata.TiffIfdMetadata = tiffPageMetadata.FindChildNode(Of Vintasoft.Imaging.Metadata.TiffIfdMetadata)()
                ' if tree node that contains information about TIFF IFD is found
                If tiffIfdMetadata IsNot Nothing Then
                        ' if TIFF IFD is found
                        If tiffIfdMetadata.ImageFileDirectory IsNot Nothing Then
                                ' print info about TIFF IFD data
                                PrintInfoAboutTiffIfdData(tiffIfdMetadata.ImageFileDirectory)
                        End If
                End If
        Next
End Sub

Private Sub PrintInfoAboutTiffIfdData(ifd As Vintasoft.Imaging.Codecs.ImageFiles.Tiff.TiffImageFileDirectory)
        System.Console.WriteLine("  TIFF IFD data:")

        ' print info about tag collection of EXIF data
        PrintTiffTagCollectionInfo(ifd.Tags, "    ")

        System.Console.WriteLine()
End Sub

Private Sub PrintTiffTagCollectionInfo(tags As Vintasoft.Imaging.Codecs.ImageFiles.Tiff.TiffTagCollection, indent As String)
        ' print tag count
        System.Console.WriteLine(String.Format("{0}Tags [{1}]:", indent, tags.Count))
        ' for each tag
        For i As Integer = 0 To tags.Count - 1
                ' print tag info
                System.Console.WriteLine(String.Format("{0}- Id={1}, Name={2}, Data={3}", indent, tags(i).Id, tags(i).Name, tags(i).Data))

                ' if tag data is TiffImageFileDirectory
                If tags(i).Data.[GetType]() Is GetType(Vintasoft.Imaging.Codecs.ImageFiles.Tiff.TiffImageFileDirectory) Then
                        Dim subIfd As Vintasoft.Imaging.Codecs.ImageFiles.Tiff.TiffImageFileDirectory = DirectCast(tags(i).Data, Vintasoft.Imaging.Codecs.ImageFiles.Tiff.TiffImageFileDirectory)
                        ' print info about tag collection of sub IFD
                        PrintTiffTagCollectionInfo(subIfd.Tags, indent & "  ")
                End If
                ' if tag data is TiffImageFileDirectory[]
                If tags(i).Data.[GetType]() Is GetType(Vintasoft.Imaging.Codecs.ImageFiles.Tiff.TiffImageFileDirectory()) Then
                        Dim subIfds As Vintasoft.Imaging.Codecs.ImageFiles.Tiff.TiffImageFileDirectory() = DirectCast(tags(i).Data, Vintasoft.Imaging.Codecs.ImageFiles.Tiff.TiffImageFileDirectory())
                        For j As Integer = 0 To subIfds.Length - 1
                                ' print info about tag collection of sub IFD
                                PrintTiffTagCollectionInfo(subIfds(j).Tags, indent & "  ")
                        Next
                End If
        Next
End Sub

// The project, which uses this code, must have references to the following assemblies:
// - Vintasoft.Imaging

public void PrintInfoAboutTiffFile(string filename)
{
    // create an image collection
    Vintasoft.Imaging.ImageCollection images = new Vintasoft.Imaging.ImageCollection();
    // add TIFF file to a collection
    images.Add(filename);

    for (int i = 0; i < images.Count; i++)
    {
        System.Console.WriteLine(string.Format("Page {0}", i));

        // get reference to a metadata tree of TIFF page
        Vintasoft.Imaging.Metadata.MetadataNode tiffPageMetadata = images[i].Metadata.MetadataTree;

        // search for tree node that contains information about TIFF IFD
        Vintasoft.Imaging.Metadata.TiffIfdMetadata tiffIfdMetadata = 
            tiffPageMetadata.FindChildNode<Vintasoft.Imaging.Metadata.TiffIfdMetadata>();
        // if tree node that contains information about TIFF IFD is found
        if (tiffIfdMetadata != null)
        {
            // if TIFF IFD is found
            if (tiffIfdMetadata.ImageFileDirectory != null)
                // print info about TIFF IFD data
                PrintInfoAboutTiffIfdData(tiffIfdMetadata.ImageFileDirectory);
        }
    }
}

private void PrintInfoAboutTiffIfdData(Vintasoft.Imaging.Codecs.ImageFiles.Tiff.TiffImageFileDirectory ifd)
{
    System.Console.WriteLine("  TIFF IFD data:");

    // print info about tag collection of EXIF data
    PrintTiffTagCollectionInfo(ifd.Tags, "    ");

    System.Console.WriteLine();
}

private void PrintTiffTagCollectionInfo(Vintasoft.Imaging.Codecs.ImageFiles.Tiff.TiffTagCollection tags, string indent)
{
    // print tag count
    System.Console.WriteLine(string.Format("{0}Tags [{1}]:", indent, tags.Count));
    // for each tag
    for (int i = 0; i < tags.Count; i++)
    {
        // print tag info
        System.Console.WriteLine(string.Format("{0}- Id={1}, Name={2}, Data={3}", indent, tags[i].Id, tags[i].Name, tags[i].Data));

        // if tag data is TiffImageFileDirectory
        if (tags[i].Data.GetType() == typeof(Vintasoft.Imaging.Codecs.ImageFiles.Tiff.TiffImageFileDirectory))
        {
            Vintasoft.Imaging.Codecs.ImageFiles.Tiff.TiffImageFileDirectory subIfd = 
                (Vintasoft.Imaging.Codecs.ImageFiles.Tiff.TiffImageFileDirectory)tags[i].Data;
            // print info about tag collection of sub IFD
            PrintTiffTagCollectionInfo(subIfd.Tags, indent + "  ");
        }
        // if tag data is TiffImageFileDirectory[]
        if (tags[i].Data.GetType() == typeof(Vintasoft.Imaging.Codecs.ImageFiles.Tiff.TiffImageFileDirectory[]))
        {
            Vintasoft.Imaging.Codecs.ImageFiles.Tiff.TiffImageFileDirectory[] subIfds = 
                (Vintasoft.Imaging.Codecs.ImageFiles.Tiff.TiffImageFileDirectory[])tags[i].Data;
            for (int j = 0; j < subIfds.Length; j++)
                // print info about tag collection of sub IFD
                PrintTiffTagCollectionInfo(subIfds[j].Tags, indent + "  ");
        }
    }
}

Here is an example that shows how to obtain EXIF information about JPEG file:

VB.NET

' The project, which uses this code, must have references to the following assemblies:
' - Vintasoft.Imaging

Public Sub PrintExifInfoAboutJpegFile(filename As String)
        ' create an instance of VintasoftImage class
        Using jpegImage As New Vintasoft.Imaging.VintasoftImage(filename)
                ' get reference to a metadata tree of JPEG page
                Dim jpegPageMetadata As Vintasoft.Imaging.Metadata.MetadataNode = jpegImage.Metadata.MetadataTree
                ' search for tree node that contains information about JPEG thumbnail
                Dim jpegApp1ExifSegmentMetadata As Vintasoft.Imaging.Metadata.JpegApp1ExifSegmentMetadata = jpegPageMetadata.FindChildNode(Of Vintasoft.Imaging.Metadata.JpegApp1ExifSegmentMetadata)()
                ' if tree node that contains EXIF information is found
                If jpegApp1ExifSegmentMetadata IsNot Nothing Then
                        ' if EXIF data is found
                        If jpegApp1ExifSegmentMetadata.IFD0 IsNot Nothing Then
                                ' print info about EXIF data
                                PrintInfoAboutExifData(jpegApp1ExifSegmentMetadata.IFD0)
                        End If

                        ' if EXIF thumbnail data is found
                        If jpegApp1ExifSegmentMetadata.IFD1 IsNot Nothing Then
                                ' print info about EXIF thumbnail data
                                PrintInfoAboutExifThumbnailData(jpegApp1ExifSegmentMetadata.IFD1)
                        End If

                        ' if EXIF thumbnail is found
                        If jpegApp1ExifSegmentMetadata.Thumbnail IsNot Nothing Then
                                ' print info about EXIF thumbnail
                                PrintInfoAboutExifThumbnail(jpegApp1ExifSegmentMetadata.Thumbnail)
                        End If
                End If
        End Using
End Sub

Private Sub PrintInfoAboutExifData(jpegApp1Ifd0Metadata As Vintasoft.Imaging.Metadata.JpegApp1Ifd0Metadata)
        System.Console.WriteLine("EXIF data:")

        ' print info about tag collection of EXIF data
        PrintExifTagCollectionInfo(jpegApp1Ifd0Metadata.ImageFileDirectory.Tags, "  ")

        System.Console.WriteLine()
End Sub

Private Sub PrintInfoAboutExifThumbnailData(jpegApp1Ifd1Metadata As Vintasoft.Imaging.Metadata.JpegApp1Ifd1Metadata)
        System.Console.WriteLine("EXIF thumbnail data:")

        ' print info about tag collection of EXIF thumbnail data
        PrintExifTagCollectionInfo(jpegApp1Ifd1Metadata.ImageFileDirectory.Tags, "  ")

        System.Console.WriteLine()
End Sub

Private Sub PrintInfoAboutExifThumbnail(thumbnailMetadata As Vintasoft.Imaging.Metadata.ThumbnailMetadata)
        System.Console.WriteLine("EXIF thumbnail:")

        ' print info about EXIF thumbnail
        System.Console.WriteLine(String.Format("  Thumbnail size: {0}", thumbnailMetadata.ThumbnailSize))

        System.Console.WriteLine()
End Sub

Private Sub PrintExifTagCollectionInfo(tags As Vintasoft.Imaging.Codecs.ImageFiles.Tiff.TiffTagCollection, indent As String)
        ' print tag count
        System.Console.WriteLine(String.Format("{0}Tags [{1}]:", indent, tags.Count))
        ' for each tag
        For i As Integer = 0 To tags.Count - 1
                ' print tag info
                System.Console.WriteLine(String.Format("{0}- Id={1}, Name={2}, Data={3}", indent, tags(i).Id, tags(i).Name, tags(i).Data))

                ' if tag data is TiffImageFileDirectory
                If tags(i).Data.[GetType]() Is GetType(Vintasoft.Imaging.Codecs.ImageFiles.Tiff.TiffImageFileDirectory) Then
                        Dim subIfd As Vintasoft.Imaging.Codecs.ImageFiles.Tiff.TiffImageFileDirectory = DirectCast(tags(i).Data, Vintasoft.Imaging.Codecs.ImageFiles.Tiff.TiffImageFileDirectory)
                        ' print info about tag collection of sub IFD
                        PrintExifTagCollectionInfo(subIfd.Tags, indent & "  ")
                End If
                ' if tag data is TiffImageFileDirectory[]
                If tags(i).Data.[GetType]() Is GetType(Vintasoft.Imaging.Codecs.ImageFiles.Tiff.TiffImageFileDirectory()) Then
                        Dim subIfds As Vintasoft.Imaging.Codecs.ImageFiles.Tiff.TiffImageFileDirectory() = DirectCast(tags(i).Data, Vintasoft.Imaging.Codecs.ImageFiles.Tiff.TiffImageFileDirectory())
                        For j As Integer = 0 To subIfds.Length - 1
                                ' print info about tag collection of sub IFD
                                PrintExifTagCollectionInfo(subIfds(j).Tags, indent & "  ")
                        Next
                End If
        Next
End Sub

// The project, which uses this code, must have references to the following assemblies:
// - Vintasoft.Imaging

public void PrintExifInfoAboutJpegFile(string filename)
{
    // create an instance of VintasoftImage class
    using (Vintasoft.Imaging.VintasoftImage jpegImage = new Vintasoft.Imaging.VintasoftImage(filename))
    {
        // get reference to a metadata tree of JPEG page
        Vintasoft.Imaging.Metadata.MetadataNode jpegPageMetadata = jpegImage.Metadata.MetadataTree;
        // search for tree node that contains information about JPEG thumbnail
        Vintasoft.Imaging.Metadata.JpegApp1ExifSegmentMetadata jpegApp1ExifSegmentMetadata = 
            jpegPageMetadata.FindChildNode<Vintasoft.Imaging.Metadata.JpegApp1ExifSegmentMetadata>();
        // if tree node that contains EXIF information is found
        if (jpegApp1ExifSegmentMetadata != null)
        {
            // if EXIF data is found
            if (jpegApp1ExifSegmentMetadata.IFD0 != null)
                // print info about EXIF data
                PrintInfoAboutExifData(jpegApp1ExifSegmentMetadata.IFD0);

            // if EXIF thumbnail data is found
            if (jpegApp1ExifSegmentMetadata.IFD1 != null)
                // print info about EXIF thumbnail data
                PrintInfoAboutExifThumbnailData(jpegApp1ExifSegmentMetadata.IFD1);

            // if EXIF thumbnail is found
            if (jpegApp1ExifSegmentMetadata.Thumbnail != null)
                // print info about EXIF thumbnail
                PrintInfoAboutExifThumbnail(jpegApp1ExifSegmentMetadata.Thumbnail);
        }
    }
}

private void PrintInfoAboutExifData(Vintasoft.Imaging.Metadata.JpegApp1Ifd0Metadata jpegApp1Ifd0Metadata)
{
    System.Console.WriteLine("EXIF data:");

    // print info about tag collection of EXIF data
    PrintExifTagCollectionInfo(jpegApp1Ifd0Metadata.ImageFileDirectory.Tags, "  ");

    System.Console.WriteLine();
}

private void PrintInfoAboutExifThumbnailData(Vintasoft.Imaging.Metadata.JpegApp1Ifd1Metadata jpegApp1Ifd1Metadata)
{
    System.Console.WriteLine("EXIF thumbnail data:");

    // print info about tag collection of EXIF thumbnail data
    PrintExifTagCollectionInfo(jpegApp1Ifd1Metadata.ImageFileDirectory.Tags, "  ");

    System.Console.WriteLine();
}

private void PrintInfoAboutExifThumbnail(Vintasoft.Imaging.Metadata.ThumbnailMetadata thumbnailMetadata)
{
    System.Console.WriteLine("EXIF thumbnail:");

    // print info about EXIF thumbnail
    System.Console.WriteLine(string.Format("  Thumbnail size: {0}", thumbnailMetadata.ThumbnailSize));

    System.Console.WriteLine();
}

private void PrintExifTagCollectionInfo(Vintasoft.Imaging.Codecs.ImageFiles.Tiff.TiffTagCollection tags, string indent)
{
    // print tag count
    System.Console.WriteLine(string.Format("{0}Tags [{1}]:", indent, tags.Count));
    // for each tag
    for (int i = 0; i < tags.Count; i++)
    {
        // print tag info
        System.Console.WriteLine(string.Format("{0}- Id={1}, Name={2}, Data={3}", indent, tags[i].Id, tags[i].Name, tags[i].Data));
        
        // if tag data is TiffImageFileDirectory
        if (tags[i].Data.GetType() == typeof(Vintasoft.Imaging.Codecs.ImageFiles.Tiff.TiffImageFileDirectory))
        {
            Vintasoft.Imaging.Codecs.ImageFiles.Tiff.TiffImageFileDirectory subIfd = 
                (Vintasoft.Imaging.Codecs.ImageFiles.Tiff.TiffImageFileDirectory)tags[i].Data;
            // print info about tag collection of sub IFD
            PrintExifTagCollectionInfo(subIfd.Tags, indent + "  ");
        }
        // if tag data is TiffImageFileDirectory[]
        if (tags[i].Data.GetType() == typeof(Vintasoft.Imaging.Codecs.ImageFiles.Tiff.TiffImageFileDirectory[]))
        {
            Vintasoft.Imaging.Codecs.ImageFiles.Tiff.TiffImageFileDirectory[] subIfds = 
                (Vintasoft.Imaging.Codecs.ImageFiles.Tiff.TiffImageFileDirectory[])tags[i].Data;
            for (int j = 0; j < subIfds.Length; j++)
                // print info about tag collection of sub IFD
                PrintExifTagCollectionInfo(subIfds[j].Tags, indent + "  ");
        }
    }
}

Here is an example that shows how to change GPS information about JPEG file:

VB.NET

' The project, which uses this code, must have references to the following assemblies:
' - Vintasoft.Imaging

Public Sub ChangeGpsInfoAboutJpegFile(filename As String)
        ' open a file stream in read-write mode
        Using fs As New System.IO.FileStream(filename, System.IO.FileMode.Open, System.IO.FileAccess.ReadWrite)
                ' create an instance of VintasoftImage class
                Using jpegImage As New Vintasoft.Imaging.VintasoftImage(fs)
                        ' get reference to a metadata tree of JPEG page
                        Dim jpegPageMetadata As Vintasoft.Imaging.Metadata.MetadataNode = jpegImage.Metadata.MetadataTree
                        ' search for tree node that contains information about JPEG thumbnail
                        Dim jpegApp1ExifSegmentMetadata As Vintasoft.Imaging.Metadata.JpegApp1ExifSegmentMetadata = jpegPageMetadata.FindChildNode(Of Vintasoft.Imaging.Metadata.JpegApp1ExifSegmentMetadata)()
                        ' if tree node that contains information about JPEG thumbnail is found
                        If jpegApp1ExifSegmentMetadata IsNot Nothing Then
                                ' if EXIF data is found
                                If jpegApp1ExifSegmentMetadata.IFD0 IsNot Nothing Then
                                        ' if GPS info is not found
                                        If jpegApp1ExifSegmentMetadata.IFD0.GpsIFD Is Nothing Then
                                                ' create node that contains GPS info
                                                jpegApp1ExifSegmentMetadata.IFD0.CreateGpsIFD()
                                        End If

                                        ' get reference to a GPS IFD
                                        Dim gpsIfd As Vintasoft.Imaging.Metadata.TiffIfdMetadata = jpegApp1ExifSegmentMetadata.IFD0.GpsIFD

                                        ' search for tag that contains info about GPS date stamp
                                        Dim gpsDateStampTag As Vintasoft.Imaging.Codecs.ImageFiles.Tiff.TiffTag = gpsIfd.ImageFileDirectory.Tags.Find(CUShort(Vintasoft.Imaging.Codecs.ImageFiles.Tiff.ExifGpsTagId.GPSDateStamp))
                                        ' if tag that contains info about GPS date stamp is found
                                        If gpsDateStampTag IsNot Nothing Then
                                                ' change the tag data
                                                gpsDateStampTag.Data = System.DateTime.Now.ToString()
                                        Else
                                                ' if tag that contains info about GPS date stamp is not found
                                                ' add the GPS date stamp
                                                gpsIfd.ImageFileDirectory.Tags.Add(CUShort(Vintasoft.Imaging.Codecs.ImageFiles.Tiff.ExifGpsTagId.GPSDateStamp), System.DateTime.Now.ToString())
                                        End If

                                        ' create an encoder for image saving
                                        Dim encoder As New Vintasoft.Imaging.Codecs.Encoders.JpegEncoder()
                                        encoder.SaveAndSwitchSource = True
                                        ' save changes to the source stream
                                        jpegImage.Save(fs, encoder)
                                End If
                        End If
                End Using
        End Using
End Sub

// The project, which uses this code, must have references to the following assemblies:
// - Vintasoft.Imaging

public void ChangeGpsInfoAboutJpegFile(string filename)
{
    // open a file stream in read-write mode
    using (System.IO.FileStream fs = new System.IO.FileStream(
        filename, System.IO.FileMode.Open, System.IO.FileAccess.ReadWrite))
    {
        // create an instance of VintasoftImage class
        using (Vintasoft.Imaging.VintasoftImage jpegImage = new Vintasoft.Imaging.VintasoftImage(fs))
        {
            // get reference to a metadata tree of JPEG page
            Vintasoft.Imaging.Metadata.MetadataNode jpegPageMetadata = jpegImage.Metadata.MetadataTree;
            // search for tree node that contains information about JPEG thumbnail
            Vintasoft.Imaging.Metadata.JpegApp1ExifSegmentMetadata jpegApp1ExifSegmentMetadata = 
                jpegPageMetadata.FindChildNode<Vintasoft.Imaging.Metadata.JpegApp1ExifSegmentMetadata>();
            // if tree node that contains information about JPEG thumbnail is found
            if (jpegApp1ExifSegmentMetadata != null)
            {
                // if EXIF data is found
                if (jpegApp1ExifSegmentMetadata.IFD0 != null)
                {
                    // if GPS info is not found
                    if (jpegApp1ExifSegmentMetadata.IFD0.GpsIFD == null)
                        // create node that contains GPS info
                        jpegApp1ExifSegmentMetadata.IFD0.CreateGpsIFD();

                    // get reference to a GPS IFD
                    Vintasoft.Imaging.Metadata.TiffIfdMetadata gpsIfd = jpegApp1ExifSegmentMetadata.IFD0.GpsIFD;

                    // search for tag that contains info about GPS date stamp
                    Vintasoft.Imaging.Codecs.ImageFiles.Tiff.TiffTag gpsDateStampTag = 
                        gpsIfd.ImageFileDirectory.Tags.Find((ushort)Vintasoft.Imaging.Codecs.ImageFiles.Tiff.ExifGpsTagId.GPSDateStamp);
                    // if tag that contains info about GPS date stamp is found
                    if (gpsDateStampTag != null)
                        // change the tag data
                        gpsDateStampTag.Data = System.DateTime.Now.ToString();
                    // if tag that contains info about GPS date stamp is not found
                    else
                        // add the GPS date stamp
                        gpsIfd.ImageFileDirectory.Tags.Add(
                            (ushort)Vintasoft.Imaging.Codecs.ImageFiles.Tiff.ExifGpsTagId.GPSDateStamp, 
                            System.DateTime.Now.ToString());

                    // create an encoder for image saving
                    Vintasoft.Imaging.Codecs.Encoders.JpegEncoder encoder = new Vintasoft.Imaging.Codecs.Encoders.JpegEncoder();
                    encoder.SaveAndSwitchSource = true;
                    // save changes to the source stream
                    jpegImage.Save(fs, encoder);
                }
            }
        }
    }
}

Here is an example that shows how to get thumbnail of JPEG file:

VB.NET

' The project, which uses this code, must have references to the following assemblies:
' - Vintasoft.Imaging

Public Function GetJpegThumbnail(filename As String) As Vintasoft.Imaging.VintasoftImage
        ' create an instance of VintasoftImage class
        Using jpegImage As New Vintasoft.Imaging.VintasoftImage(filename)
                ' get reference to a metadata tree of JPEG page
                Dim jpegPageMetadata As Vintasoft.Imaging.Metadata.MetadataNode = jpegImage.Metadata.MetadataTree
                ' search for tree node that contains information about JPEG thumbnail
                Dim jpegThumbnailMetadata As Vintasoft.Imaging.Metadata.JpegApp1ThumbnailMetadata = jpegPageMetadata.FindChildNode(Of Vintasoft.Imaging.Metadata.JpegApp1ThumbnailMetadata)()
                ' if tree node that contains information about JPEG thumbnail is found
                If jpegThumbnailMetadata IsNot Nothing Then
                        ' return thumbnail of JPEG page
                        Return jpegThumbnailMetadata.ThumbnailImage
                End If

                ' JPEG page does not have thumbnail
                Return Nothing
        End Using
End Function

// The project, which uses this code, must have references to the following assemblies:
// - Vintasoft.Imaging

public Vintasoft.Imaging.VintasoftImage GetJpegThumbnail(string filename)
{
    // create an instance of VintasoftImage class
    using (Vintasoft.Imaging.VintasoftImage jpegImage = 
        new Vintasoft.Imaging.VintasoftImage(filename))
    {
        // get reference to a metadata tree of JPEG page
        Vintasoft.Imaging.Metadata.MetadataNode jpegPageMetadata = jpegImage.Metadata.MetadataTree;
        // search for tree node that contains information about JPEG thumbnail
        Vintasoft.Imaging.Metadata.JpegApp1ThumbnailMetadata jpegThumbnailMetadata = 
            jpegPageMetadata.FindChildNode<Vintasoft.Imaging.Metadata.JpegApp1ThumbnailMetadata>();
        // if tree node that contains information about JPEG thumbnail is found
        if (jpegThumbnailMetadata != null)
            // return thumbnail of JPEG page
            return jpegThumbnailMetadata.ThumbnailImage;

        // JPEG page does not have thumbnail
        return null;
    }
}

Access to the metadata of class instance, which is derived from ImageFile class

ImageFileBase<T> class is an abstract class providing access to an image file. For each of supported image file format exist a class derived from ImageFileBase<T> class, notably:

BmpFile for BMP format
GifFile for GIF format
IconFile for ICO format
Jbig2File for JBIG2 format
JpegFile for JPEG format
Jpeg2000File for JPEG2000 format
PngFile for PNG format
TiffFile for TIFF format
DicomFile for DICOM format
RawImageFile for RAW (DNG, NRW, NEF, CR2, CRW) formats

Metadata of image file can be obtained using properties and methods of instance of class, which is derived from ImageFileBase<T> class. Also the instance of class, which is derived from ImageFileBase<T> class, provides access to the file pages.

Here is an example that shows how to obtain format and version of TIFF file:

VB.NET

' The project, which uses this code, must have references to the following assemblies:
' - Vintasoft.Imaging

Public Sub PrintInfoAboutTiffFileFormatAndVersion(filename As String)
        ' create an instance of TiffFile class
        Using tiffFile As New Vintasoft.Imaging.Codecs.ImageFiles.Tiff.TiffFile(filename)
                System.Console.WriteLine(String.Format("TIFF Format={0} Version={1}", tiffFile.Format, tiffFile.Version))
        End Using
End Sub

// The project, which uses this code, must have references to the following assemblies:
// - Vintasoft.Imaging

public void PrintInfoAboutTiffFileFormatAndVersion(string filename)
{
    // create an instance of TiffFile class
    using (Vintasoft.Imaging.Codecs.ImageFiles.Tiff.TiffFile tiffFile = 
        new Vintasoft.Imaging.Codecs.ImageFiles.Tiff.TiffFile(filename))
    {
        System.Console.WriteLine(string.Format("TIFF Format={0} Version={1}", tiffFile.Format, tiffFile.Version));
    }
}

ImagePage class is an abstract class providing access to an image page. For each of supported image file format exist a class, which is derived from ImagePage class, notably:

BmpPage for BMP format
GifPage for GIF format
IconPage for ICO format
Jbig2Page for JBIG2 format
JpegPage for JPEG format
Jpeg2000Page for JPEG2000 format
PngPage for PNG format
TiffPage for TIFF format
DngPage for DNG format
Cr2Page for CR2 format
CrwPage for CRW format
NefPage for NEF format
DicomFrame for DICOM format

Metadata of image page can be obtained using properties and methods of instance of class, which is derived from ImagePage class.

Here is an example that shows how to obtain information about TIFF tags of TIFF file:

VB.NET

' The project, which uses this code, must have references to the following assemblies:
' - Vintasoft.Imaging

Public Sub PrintInfoAboutTiffFile(filename As String)
        ' create an instance of TiffFile class
        Using tiffFile As New Vintasoft.Imaging.Codecs.ImageFiles.Tiff.TiffFile(filename)
                ' for each TIFF page
                For i As Integer = 0 To tiffFile.Pages.Count - 1
                        System.Console.WriteLine(String.Format("Page {0}", i))

                        ' print info about TIFF IFD data
                        PrintInfoAboutTiffIfdData(tiffFile.Pages(0).IFD)
                Next
        End Using
End Sub

Private Sub PrintInfoAboutTiffIfdData(ifd As Vintasoft.Imaging.Codecs.ImageFiles.Tiff.TiffImageFileDirectory)
        System.Console.WriteLine("  TIFF IFD data:")

        ' print info about tag collection of EXIF data
        PrintTiffTagCollectionInfo(ifd.Tags, "    ")

        System.Console.WriteLine()
End Sub

Private Sub PrintTiffTagCollectionInfo(tags As Vintasoft.Imaging.Codecs.ImageFiles.Tiff.TiffTagCollection, indent As String)
        ' print tag count
        System.Console.WriteLine(String.Format("{0}Tags [{1}]:", indent, tags.Count))
        ' for each tag
        For i As Integer = 0 To tags.Count - 1
                ' print tag info
                System.Console.WriteLine(String.Format("{0}- Id={1}, Name={2}, Data={3}", indent, tags(i).Id, tags(i).Name, tags(i).Data))

                ' if tag data is TiffImageFileDirectory
                If tags(i).Data.[GetType]() Is GetType(Vintasoft.Imaging.Codecs.ImageFiles.Tiff.TiffImageFileDirectory) Then
                        Dim subIfd As Vintasoft.Imaging.Codecs.ImageFiles.Tiff.TiffImageFileDirectory = DirectCast(tags(i).Data, Vintasoft.Imaging.Codecs.ImageFiles.Tiff.TiffImageFileDirectory)
                        ' print info about tag collection of sub IFD
                        PrintTiffTagCollectionInfo(subIfd.Tags, indent & "  ")
                End If
                ' if tag data is TiffImageFileDirectory[]
                If tags(i).Data.[GetType]() Is GetType(Vintasoft.Imaging.Codecs.ImageFiles.Tiff.TiffImageFileDirectory()) Then
                        Dim subIfds As Vintasoft.Imaging.Codecs.ImageFiles.Tiff.TiffImageFileDirectory() = DirectCast(tags(i).Data, Vintasoft.Imaging.Codecs.ImageFiles.Tiff.TiffImageFileDirectory())
                        For j As Integer = 0 To subIfds.Length - 1
                                ' print info about tag collection of sub IFD
                                PrintTiffTagCollectionInfo(subIfds(j).Tags, indent & "  ")
                        Next
                End If
        Next
End Sub

// The project, which uses this code, must have references to the following assemblies:
// - Vintasoft.Imaging

public void PrintInfoAboutTiffFile(string filename)
{
    // create an instance of TiffFile class
    using (Vintasoft.Imaging.Codecs.ImageFiles.Tiff.TiffFile tiffFile = 
        new Vintasoft.Imaging.Codecs.ImageFiles.Tiff.TiffFile(filename))
    {
        // for each TIFF page
        for (int i = 0; i < tiffFile.Pages.Count; i++)
        {
            System.Console.WriteLine(string.Format("Page {0}", i));

            // print info about TIFF IFD data
            PrintInfoAboutTiffIfdData(tiffFile.Pages[0].IFD);
        }
    }
}

private void PrintInfoAboutTiffIfdData(
    Vintasoft.Imaging.Codecs.ImageFiles.Tiff.TiffImageFileDirectory ifd)
{
    System.Console.WriteLine("  TIFF IFD data:");

    // print info about tag collection of EXIF data
    PrintTiffTagCollectionInfo(ifd.Tags, "    ");

    System.Console.WriteLine();
}

private void PrintTiffTagCollectionInfo(
    Vintasoft.Imaging.Codecs.ImageFiles.Tiff.TiffTagCollection tags, string indent)
{
    // print tag count
    System.Console.WriteLine(string.Format("{0}Tags [{1}]:", indent, tags.Count));
    // for each tag
    for (int i = 0; i < tags.Count; i++)
    {
        // print tag info
        System.Console.WriteLine(string.Format("{0}- Id={1}, Name={2}, Data={3}", indent, tags[i].Id, tags[i].Name, tags[i].Data));

        // if tag data is TiffImageFileDirectory
        if (tags[i].Data.GetType() == typeof(
            Vintasoft.Imaging.Codecs.ImageFiles.Tiff.TiffImageFileDirectory))
        {
            Vintasoft.Imaging.Codecs.ImageFiles.Tiff.TiffImageFileDirectory subIfd = 
                (Vintasoft.Imaging.Codecs.ImageFiles.Tiff.TiffImageFileDirectory)tags[i].Data;
            // print info about tag collection of sub IFD
            PrintTiffTagCollectionInfo(subIfd.Tags, indent + "  ");
        }
        // if tag data is TiffImageFileDirectory[]
        if (tags[i].Data.GetType() == typeof(
            Vintasoft.Imaging.Codecs.ImageFiles.Tiff.TiffImageFileDirectory[]))
        {
            Vintasoft.Imaging.Codecs.ImageFiles.Tiff.TiffImageFileDirectory[] subIfds = 
                (Vintasoft.Imaging.Codecs.ImageFiles.Tiff.TiffImageFileDirectory[])tags[i].Data;
            for (int j = 0; j < subIfds.Length; j++)
                // print info about tag collection of sub IFD
                PrintTiffTagCollectionInfo(subIfds[j].Tags, indent + "  ");
        }
    }
}

Here is an example that shows how to obtain EXIF information about JPEG file:

VB.NET

' The project, which uses this code, must have references to the following assemblies:
' - Vintasoft.Imaging

Public Sub PrintExifInfoAboutJpegFile(filename As String)
        ' create an instance of JpegFile class
        Using jpegFile As New Vintasoft.Imaging.Codecs.ImageFiles.Jpeg.JpegFile(filename)
                ' if JPEG page contains EXIF information
                If jpegFile.Page.Exif IsNot Nothing Then
                        Dim exifData As Vintasoft.Imaging.Codecs.ImageFiles.Jpeg.ExifData = jpegFile.Page.Exif

                        ' if EXIF data is found
                        If exifData.ImageFileDirectory IsNot Nothing Then
                                ' print info about EXIF data
                                PrintInfoAboutExifData(exifData.ImageFileDirectory)
                        End If

                        ' if EXIF thumbnail data is found
                        If exifData.ThumbnailFileDirectory IsNot Nothing Then
                                ' print info about EXIF thumbnail data
                                PrintInfoAboutExifThumbnailData(exifData.ThumbnailFileDirectory)
                        End If

                        ' if EXIF thumbnail is found
                        If exifData.HasThumbnail Then
                                ' print info about EXIF thumbnail
                                PrintInfoAboutExifThumbnail(exifData)
                        End If
                End If
        End Using
End Sub

Private Sub PrintInfoAboutExifData(exifDataIfd As Vintasoft.Imaging.Codecs.ImageFiles.Tiff.TiffImageFileDirectory)
        System.Console.WriteLine("EXIF data:")

        ' print info about tag collection of EXIF data
        PrintExifTagCollectionInfo(exifDataIfd.Tags, "  ")

        System.Console.WriteLine()
End Sub

Private Sub PrintInfoAboutExifThumbnailData(exifThumbnailDataIfd As Vintasoft.Imaging.Codecs.ImageFiles.Tiff.TiffImageFileDirectory)
        System.Console.WriteLine("EXIF thumbnail data:")

        ' print info about tag collection of EXIF thumbnail data
        PrintExifTagCollectionInfo(exifThumbnailDataIfd.Tags, "  ")

        System.Console.WriteLine()
End Sub

Private Sub PrintInfoAboutExifThumbnail(exifData As Vintasoft.Imaging.Codecs.ImageFiles.Jpeg.ExifData)
        System.Console.WriteLine("EXIF thumbnail:")

        Using thumbnailImage As Vintasoft.Imaging.VintasoftImage = exifData.GetThumbnail()
                ' print info about EXIF thumbnail
                System.Console.WriteLine(String.Format("  Thumbnail size: {0}x{1}", thumbnailImage.Width, thumbnailImage.Height))
        End Using

        System.Console.WriteLine()
End Sub

Private Sub PrintExifTagCollectionInfo(tags As Vintasoft.Imaging.Codecs.ImageFiles.Tiff.TiffTagCollection, indent As String)
        ' print tag count
        System.Console.WriteLine(String.Format("{0}Tags [{1}]:", indent, tags.Count))
        ' for each tag
        For i As Integer = 0 To tags.Count - 1
                ' print tag info
                System.Console.WriteLine(String.Format("{0}- Id={1}, Name={2}, Data={3}", indent, tags(i).Id, tags(i).Name, tags(i).Data))

                ' if tag data is TiffImageFileDirectory
                If tags(i).Data.[GetType]() Is GetType(Vintasoft.Imaging.Codecs.ImageFiles.Tiff.TiffImageFileDirectory) Then
                        Dim subIfd As Vintasoft.Imaging.Codecs.ImageFiles.Tiff.TiffImageFileDirectory = DirectCast(tags(i).Data, Vintasoft.Imaging.Codecs.ImageFiles.Tiff.TiffImageFileDirectory)
                        ' print info about tag collection of sub IFD
                        PrintExifTagCollectionInfo(subIfd.Tags, indent & "  ")
                End If
                ' if tag data is TiffImageFileDirectory[]
                If tags(i).Data.[GetType]() Is GetType(Vintasoft.Imaging.Codecs.ImageFiles.Tiff.TiffImageFileDirectory()) Then
                        Dim subIfds As Vintasoft.Imaging.Codecs.ImageFiles.Tiff.TiffImageFileDirectory() = DirectCast(tags(i).Data, Vintasoft.Imaging.Codecs.ImageFiles.Tiff.TiffImageFileDirectory())
                        For j As Integer = 0 To subIfds.Length - 1
                                ' print info about tag collection of sub IFD
                                PrintExifTagCollectionInfo(subIfds(j).Tags, indent & "  ")
                        Next
                End If
        Next
End Sub

// The project, which uses this code, must have references to the following assemblies:
// - Vintasoft.Imaging

public void PrintExifInfoAboutJpegFile(string filename)
{
    // create an instance of JpegFile class
    using (Vintasoft.Imaging.Codecs.ImageFiles.Jpeg.JpegFile jpegFile = 
        new Vintasoft.Imaging.Codecs.ImageFiles.Jpeg.JpegFile(filename))
    {
        // if JPEG page contains EXIF information
        if (jpegFile.Page.Exif != null)
        {
            Vintasoft.Imaging.Codecs.ImageFiles.Jpeg.ExifData exifData = jpegFile.Page.Exif;

            // if EXIF data is found
            if (exifData.ImageFileDirectory != null)
                // print info about EXIF data
                PrintInfoAboutExifData(exifData.ImageFileDirectory);

            // if EXIF thumbnail data is found
            if (exifData.ThumbnailFileDirectory != null)
                // print info about EXIF thumbnail data
                PrintInfoAboutExifThumbnailData(exifData.ThumbnailFileDirectory);

            // if EXIF thumbnail is found
            if (exifData.HasThumbnail)
                // print info about EXIF thumbnail
                PrintInfoAboutExifThumbnail(exifData);
        }
    }
}

private void PrintInfoAboutExifData(
    Vintasoft.Imaging.Codecs.ImageFiles.Tiff.TiffImageFileDirectory exifDataIfd)
{
    System.Console.WriteLine("EXIF data:");

    // print info about tag collection of EXIF data
    PrintExifTagCollectionInfo(exifDataIfd.Tags, "  ");

    System.Console.WriteLine();
}

private void PrintInfoAboutExifThumbnailData(
    Vintasoft.Imaging.Codecs.ImageFiles.Tiff.TiffImageFileDirectory exifThumbnailDataIfd)
{
    System.Console.WriteLine("EXIF thumbnail data:");

    // print info about tag collection of EXIF thumbnail data
    PrintExifTagCollectionInfo(exifThumbnailDataIfd.Tags, "  ");

    System.Console.WriteLine();
}

private void PrintInfoAboutExifThumbnail(
    Vintasoft.Imaging.Codecs.ImageFiles.Jpeg.ExifData exifData)
{
    System.Console.WriteLine("EXIF thumbnail:");

    using (Vintasoft.Imaging.VintasoftImage thumbnailImage = exifData.GetThumbnail())
    {
        // print info about EXIF thumbnail
        System.Console.WriteLine(string.Format("  Thumbnail size: {0}x{1}", thumbnailImage.Width, thumbnailImage.Height));
    }

    System.Console.WriteLine();
}

private void PrintExifTagCollectionInfo(
    Vintasoft.Imaging.Codecs.ImageFiles.Tiff.TiffTagCollection tags, string indent)
{
    // print tag count
    System.Console.WriteLine(string.Format("{0}Tags [{1}]:", indent, tags.Count));
    // for each tag
    for (int i = 0; i < tags.Count; i++)
    {
        // print tag info
        System.Console.WriteLine(string.Format("{0}- Id={1}, Name={2}, Data={3}", indent, tags[i].Id, tags[i].Name, tags[i].Data));
        
        // if tag data is TiffImageFileDirectory
        if (tags[i].Data.GetType() == typeof(
            Vintasoft.Imaging.Codecs.ImageFiles.Tiff.TiffImageFileDirectory))
        {
            Vintasoft.Imaging.Codecs.ImageFiles.Tiff.TiffImageFileDirectory subIfd = 
                (Vintasoft.Imaging.Codecs.ImageFiles.Tiff.TiffImageFileDirectory)tags[i].Data;
            // print info about tag collection of sub IFD
            PrintExifTagCollectionInfo(subIfd.Tags, indent + "  ");
        }
        // if tag data is TiffImageFileDirectory[]
        if (tags[i].Data.GetType() == typeof(
            Vintasoft.Imaging.Codecs.ImageFiles.Tiff.TiffImageFileDirectory[]))
        {
            Vintasoft.Imaging.Codecs.ImageFiles.Tiff.TiffImageFileDirectory[] subIfds = 
                (Vintasoft.Imaging.Codecs.ImageFiles.Tiff.TiffImageFileDirectory[])tags[i].Data;
            for (int j = 0; j < subIfds.Length; j++)
                // print info about tag collection of sub IFD
                PrintExifTagCollectionInfo(subIfds[j].Tags, indent + "  ");
        }
    }
}

Here is an example that shows how to change GPS information about JPEG file:

VB.NET

' The project, which uses this code, must have references to the following assemblies:
' - Vintasoft.Imaging

Public Sub ChangeGpsInfoAboutJpegFile(filename As String)
        ' create an instance of JpegFile class
        Using jpegFile As New Vintasoft.Imaging.Codecs.ImageFiles.Jpeg.JpegFile(filename)
                ' if JPEG page contains EXIF information
                If jpegFile.Page.Exif IsNot Nothing Then
                        Dim exifData As Vintasoft.Imaging.Codecs.ImageFiles.Jpeg.ExifData = jpegFile.Page.Exif

                        ' if EXIF data is found
                        If exifData.ImageFileDirectory IsNot Nothing Then
                                ' if GPS info is not found
                                If exifData.ImageFileDirectory.GpsTags Is Nothing Then
                                        ' create tag collection that contains GPS info
                                        exifData.ImageFileDirectory.GpsTags = New Vintasoft.Imaging.Codecs.ImageFiles.Tiff.TiffTagCollection()
                                End If

                                ' get reference to a GPS tags
                                Dim gpsTags As Vintasoft.Imaging.Codecs.ImageFiles.Tiff.TiffTagCollection = exifData.ImageFileDirectory.GpsTags

                                ' search for tag that contains info about GPS date stamp
                                Dim gpsDateStampTag As Vintasoft.Imaging.Codecs.ImageFiles.Tiff.TiffTag = gpsTags.Find(CUShort(Vintasoft.Imaging.Codecs.ImageFiles.Tiff.ExifGpsTagId.GPSDateStamp))
                                ' if tag that contains info about GPS date stamp is found
                                If gpsDateStampTag IsNot Nothing Then
                                        ' change the tag data
                                        gpsDateStampTag.Data = System.DateTime.Now.ToString()
                                Else
                                        ' if tag that contains info about GPS date stamp is not found
                                        ' add the GPS date stamp
                                        gpsTags.Add(CUShort(Vintasoft.Imaging.Codecs.ImageFiles.Tiff.ExifGpsTagId.GPSDateStamp), System.DateTime.Now.ToString())
                                End If

                                ' save changes to the source file
                                jpegFile.SaveChanges()
                        End If
                End If
        End Using
End Sub

// The project, which uses this code, must have references to the following assemblies:
// - Vintasoft.Imaging

public void ChangeGpsInfoAboutJpegFile(string filename)
{
    // create an instance of JpegFile class
    using (Vintasoft.Imaging.Codecs.ImageFiles.Jpeg.JpegFile jpegFile = 
        new Vintasoft.Imaging.Codecs.ImageFiles.Jpeg.JpegFile(filename))
    {
        // if JPEG page contains EXIF information
        if (jpegFile.Page.Exif != null)
        {
            Vintasoft.Imaging.Codecs.ImageFiles.Jpeg.ExifData exifData = jpegFile.Page.Exif;

            // if EXIF data is found
            if (exifData.ImageFileDirectory != null)
            {
                // if GPS info is not found
                if (exifData.ImageFileDirectory.GpsTags == null)
                    // create tag collection that contains GPS info
                    exifData.ImageFileDirectory.GpsTags = 
                        new Vintasoft.Imaging.Codecs.ImageFiles.Tiff.TiffTagCollection();

                // get reference to a GPS tags
                Vintasoft.Imaging.Codecs.ImageFiles.Tiff.TiffTagCollection gpsTags = 
                    exifData.ImageFileDirectory.GpsTags;

                // search for tag that contains info about GPS date stamp
                Vintasoft.Imaging.Codecs.ImageFiles.Tiff.TiffTag gpsDateStampTag = 
                    gpsTags.Find((ushort)Vintasoft.Imaging.Codecs.ImageFiles.Tiff.ExifGpsTagId.GPSDateStamp);
                // if tag that contains info about GPS date stamp is found
                if (gpsDateStampTag != null)
                    // change the tag data
                    gpsDateStampTag.Data = System.DateTime.Now.ToString();
                // if tag that contains info about GPS date stamp is not found
                else
                    // add the GPS date stamp
                    gpsTags.Add((ushort)Vintasoft.Imaging.Codecs.ImageFiles.Tiff.ExifGpsTagId.GPSDateStamp, 
                        System.DateTime.Now.ToString());

                // save changes to the source file
                jpegFile.SaveChanges();
            }
        }
    }
}

Here is an example that shows how to get thumbnail of JPEG file:

VB.NET

' The project, which uses this code, must have references to the following assemblies:
' - Vintasoft.Imaging

Public Function GetJpegThumbnail(filename As String) As Vintasoft.Imaging.VintasoftImage
        ' create an instance of JpegFile class
        Using jpegFile As New Vintasoft.Imaging.Codecs.ImageFiles.Jpeg.JpegFile(filename)
                ' if JPEG page contains EXIF information
                If jpegFile.Page.Exif IsNot Nothing Then
                        Dim exifData As Vintasoft.Imaging.Codecs.ImageFiles.Jpeg.ExifData = jpegFile.Page.Exif

                        ' if EXIF thumbnail is found
                        If exifData.HasThumbnail Then
                                ' return thumbnail of JPEG page
                                Return exifData.GetThumbnail()
                        End If
                End If

                ' JPEG page does not have thumbnail
                Return Nothing
        End Using
End Function

// The project, which uses this code, must have references to the following assemblies:
// - Vintasoft.Imaging

public Vintasoft.Imaging.VintasoftImage GetJpegThumbnail(string filename)
{
    // create an instance of JpegFile class
    using (Vintasoft.Imaging.Codecs.ImageFiles.Jpeg.JpegFile jpegFile = 
        new Vintasoft.Imaging.Codecs.ImageFiles.Jpeg.JpegFile(filename))
    {
        // if JPEG page contains EXIF information
        if (jpegFile.Page.Exif != null)
        {
            Vintasoft.Imaging.Codecs.ImageFiles.Jpeg.ExifData exifData = jpegFile.Page.Exif;

            // if EXIF thumbnail is found
            if (exifData.HasThumbnail)
                // return thumbnail of JPEG page
                return exifData.GetThumbnail();
        }

        // JPEG page does not have thumbnail
        return null;
    }
}

Access to the metadata of PdfDocument object

PdfDocument class provides access to a PDF document. Metadata of PDF document can be obtained using properties and methods of PdfDocument object. Also the PdfDocument object provides access to the PDF file pages.

Here is an example that shows how to obtain information about PDF document:

VB.NET

' The project, which uses this code, must have references to the following assemblies:
' - Vintasoft.Imaging
' - Vintasoft.Imaging.Pdf

Public Sub GetPdfDocumentInfo(filename As String)
        ' create an instance of PdfDocument class
        Using pdfDocument As New Vintasoft.Imaging.Pdf.PdfDocument(filename)
                System.Console.WriteLine(String.Format("PDF document: '{0}'", filename))

                Dim documentInformation As Vintasoft.Imaging.Pdf.Tree.PdfDocumentInformation = pdfDocument.DocumentInformation
                System.Console.WriteLine(String.Format("  Creator: {0}", documentInformation.Creator))
                System.Console.WriteLine(String.Format("  Producer: {0}", documentInformation.Producer))
                System.Console.WriteLine(String.Format("  Creation date: {0}", documentInformation.CreationDate))
                System.Console.WriteLine(String.Format("  Last modification date: {0}", documentInformation.ModifyDate))
                System.Console.WriteLine(String.Format("  Author: {0}", documentInformation.Author))
                System.Console.WriteLine(String.Format("  Title: {0}", documentInformation.Title))
                System.Console.WriteLine(String.Format("  Subject: {0}", documentInformation.Subject))
                System.Console.WriteLine(String.Format("  Keywords: {0}", documentInformation.Keywords))
        End Using
End Sub

// The project, which uses this code, must have references to the following assemblies:
// - Vintasoft.Imaging
// - Vintasoft.Imaging.Pdf

public void GetPdfDocumentInfo(string filename)
{
    // create an instance of PdfDocument class
    using (Vintasoft.Imaging.Pdf.PdfDocument pdfDocument = 
        new Vintasoft.Imaging.Pdf.PdfDocument(filename))
    {
        System.Console.WriteLine(string.Format("PDF document: '{0}'", filename));

        Vintasoft.Imaging.Pdf.Tree.PdfDocumentInformation documentInformation = pdfDocument.DocumentInformation;
        System.Console.WriteLine(string.Format("  Creator: {0}", documentInformation.Creator));
        System.Console.WriteLine(string.Format("  Producer: {0}", documentInformation.Producer));
        System.Console.WriteLine(string.Format("  Creation date: {0}", documentInformation.CreationDate));
        System.Console.WriteLine(string.Format("  Last modification date: {0}", documentInformation.ModifyDate));
        System.Console.WriteLine(string.Format("  Author: {0}", documentInformation.Author));
        System.Console.WriteLine(string.Format("  Title: {0}", documentInformation.Title));
        System.Console.WriteLine(string.Format("  Subject: {0}", documentInformation.Subject));
        System.Console.WriteLine(string.Format("  Keywords: {0}", documentInformation.Keywords));
    }
}

PdfPage class provides access to a page of PDF document. The metadata of PDF page can be obtained using properties and methods of PdfPage object.

Here is an example that shows how to get size of PDF document page:

VB.NET

' The project, which uses this code, must have references to the following assemblies:
' - Vintasoft.Imaging
' - Vintasoft.Imaging.Pdf

Public Function GetFirstPdfPageSize(filename As String) As System.Drawing.SizeF
        ' create an instance of PdfDocument class
        Using pdfDocument As New Vintasoft.Imaging.Pdf.PdfDocument(filename)
                If pdfDocument.Pages.Count = 0 Then
                        Return System.Drawing.SizeF.Empty
                End If

                Return pdfDocument.Pages(0).Size
        End Using
End Function

// The project, which uses this code, must have references to the following assemblies:
// - Vintasoft.Imaging
// - Vintasoft.Imaging.Pdf

public System.Drawing.SizeF GetFirstPdfPageSize(string filename)
{
    // create an instance of PdfDocument class
    using (Vintasoft.Imaging.Pdf.PdfDocument pdfDocument =
        new Vintasoft.Imaging.Pdf.PdfDocument(filename))
    {
        if (pdfDocument.Pages.Count == 0)
            return System.Drawing.SizeF.Empty;

        return pdfDocument.Pages[0].Size;
    }
}

Here is an example that shows how to get thumbnail of PDF document page:

VB.NET

' The project, which uses this code, must have references to the following assemblies:
' - Vintasoft.Imaging
' - Vintasoft.Imaging.Pdf

Public Function GetFirstPdfPageThumbnail(filename As String) As Vintasoft.Imaging.VintasoftImage
        ' create an instance of PdfDocument class
        Using pdfDocument As New Vintasoft.Imaging.Pdf.PdfDocument(filename)
                If pdfDocument.Pages.Count = 0 Then
                        Return Nothing
                End If

                Return pdfDocument.Pages(0).GetThumbnail(100, 100)
        End Using
End Function

// The project, which uses this code, must have references to the following assemblies:
// - Vintasoft.Imaging
// - Vintasoft.Imaging.Pdf

public Vintasoft.Imaging.VintasoftImage GetFirstPdfPageThumbnail(string filename)
{
    // create an instance of PdfDocument class
    using (Vintasoft.Imaging.Pdf.PdfDocument pdfDocument = 
        new Vintasoft.Imaging.Pdf.PdfDocument(filename))
    {
        if (pdfDocument.Pages.Count == 0)
            return null;

        return pdfDocument.Pages[0].GetThumbnail(100, 100);
    }
}

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