''' <summary>
''' Removes optional content groups with specified names from PDF document.
''' </summary>
''' <param name="inFilename">The input PDF filename.</param>
''' <param name="outFilename">The output PDF filename.</param>
''' <param name="groupNames">The names of optional content groups to remove.</param>
Public Shared Sub RemoveOptionalContent(inFilename As String, outFilename As String, ParamArray groupNames As String())
    ' open input PDF document
    Using document As New Vintasoft.Imaging.Pdf.PdfDocument(inFilename)
        ' a list of optional content groups, which should be removed
        Dim contentGroupsToRemove As New System.Collections.Generic.List(Of Vintasoft.Imaging.Pdf.Tree.PdfMarkedContentProperty)()
        ' if PDF document has optional content groups
        If document.OptionalContentProperties IsNot Nothing AndAlso document.OptionalContentProperties.OptionalContentGroups IsNot Nothing Then
            ' for each optional content group
            For Each group As Vintasoft.Imaging.Pdf.Tree.OptionalContent.PdfOptionalContentGroup In document.OptionalContentProperties.OptionalContentGroups
                ' if optional content group must be removed
                If System.Array.IndexOf(groupNames, group.Name) >= 0 Then
                    ' add optional content group to the remove list
                    contentGroupsToRemove.Add(group)
                End If
            Next
        End If

        ' create command for removing marked content from PDF document
        Dim removeMarkedContentCommand As New Vintasoft.Imaging.Pdf.Processing.RemoveMarkedContentCommand()
        ' specify optional content groups, which should be removed
        removeMarkedContentCommand.RemovingMarkedContent = contentGroupsToRemove.ToArray()
        ' remove optional content groups from PDF document
        removeMarkedContentCommand.Execute(document)

        ' save changed PDF document to the output file
        document.Pack(outFilename)
    End Using
End Sub

/// <summary>
/// Removes optional content groups with specified names from PDF document.
/// </summary>
/// <param name="inFilename">The input PDF filename.</param>
/// <param name="outFilename">The output PDF filename.</param>
/// <param name="groupNames">The names of optional content groups to remove.</param>
public static void RemoveOptionalContent(string inFilename, string outFilename, params string[] groupNames)
{
    // open input PDF document
    using (Vintasoft.Imaging.Pdf.PdfDocument document = new Vintasoft.Imaging.Pdf.PdfDocument(inFilename))
    {
        // a list of optional content groups, which should be removed
        System.Collections.Generic.List<Vintasoft.Imaging.Pdf.Tree.PdfMarkedContentProperty> contentGroupsToRemove =
            new System.Collections.Generic.List<Vintasoft.Imaging.Pdf.Tree.PdfMarkedContentProperty>();
        // if PDF document has optional content groups
        if (document.OptionalContentProperties != null && document.OptionalContentProperties.OptionalContentGroups != null)
        {
            // for each optional content group
            foreach (Vintasoft.Imaging.Pdf.Tree.OptionalContent.PdfOptionalContentGroup group in document.OptionalContentProperties.OptionalContentGroups)
            {
                // if optional content group must be removed
                if (System.Array.IndexOf(groupNames, group.Name) >= 0)
                    // add optional content group to the remove list
                    contentGroupsToRemove.Add(group);
            }
        }

        // create command for removing marked content from PDF document
        Vintasoft.Imaging.Pdf.Processing.RemoveMarkedContentCommand removeMarkedContentCommand =
            new Vintasoft.Imaging.Pdf.Processing.RemoveMarkedContentCommand();
        // specify optional content groups, which should be removed
        removeMarkedContentCommand.RemovingMarkedContent = contentGroupsToRemove.ToArray();
        // remove optional content groups from PDF document
        removeMarkedContentCommand.Execute(document);

        // save changed PDF document to the output file
        document.Pack(outFilename);
    }
}