''' <summary>
''' Creates the redaction mark with custom appearance and applies the redaction mark
''' to PDF page.
''' </summary>
Public Shared Sub TestRedactionMarkAppearance(viewer As Vintasoft.Imaging.UI.ImageViewer)
    ' if image viewer does not have image
    If viewer.Image Is Nothing Then
        Throw New System.InvalidOperationException()
    End If

    ' if image viewer contains not PDF page
    Dim page As Vintasoft.Imaging.Pdf.Tree.PdfPage = Vintasoft.Imaging.Pdf.PdfDocumentController.GetPageAssociatedWithImage(viewer.Image)
    If page Is Nothing Then
        Throw New System.InvalidOperationException()
    End If

    ' create and set PdfRemoveContentTool as current tool of image viewer
    Dim removeContentTool As New Vintasoft.Imaging.Pdf.UI.PdfRemoveContentTool()
    viewer.VisualTool = removeContentTool

    ' create the redaction mark
    Dim mark As New Vintasoft.Imaging.Pdf.UI.RedactionMark(viewer.Image)
    ' specify that redaction mark must remove all PDF content
    mark.MarkType = Vintasoft.Imaging.Pdf.PdfRedactionMarkType.RemoveAll
    ' calculate and specify the redaction mark rectangle
    Dim rect As System.Drawing.RectangleF = page.MediaBox
    rect.Inflate(-rect.Width / 4, -rect.Height / 4)
    mark.SelectedRect = rect

    ' add the redaction mark to a list of redaction marks of visual tool
    removeContentTool.Add(mark)

    ' create redaction mark appearance
    Dim textBox As New Vintasoft.Imaging.Pdf.Drawing.GraphicsFigures.TextBoxFigure(New Vintasoft.Imaging.Pdf.Drawing.PdfBrush(System.Drawing.Color.Red), "TOP SECRET", page.Document.FontManager.GetStandardFont(Vintasoft.Imaging.Pdf.Tree.Fonts.PdfStandardFontType.Helvetica), 0)
    textBox.TextAlignment = Vintasoft.Imaging.Pdf.Drawing.PdfContentAlignment.Center
    textBox.Brush = New Vintasoft.Imaging.Pdf.Drawing.PdfBrush(System.Drawing.Color.Black)
    textBox.AutoFontSize = True
    removeContentTool.RedactionMarkAppearance = textBox

    ' apply redaction marks
    removeContentTool.ApplyRedactionMarks()
End Sub

/// <summary>
/// Creates the redaction mark with custom appearance and applies the redaction mark
/// to PDF page.
/// </summary>
public static void TestRedactionMarkAppearance(Vintasoft.Imaging.UI.ImageViewer viewer)
{
    // if image viewer does not have image
    if (viewer.Image == null)
        throw new System.InvalidOperationException();

    // if image viewer contains not PDF page
    Vintasoft.Imaging.Pdf.Tree.PdfPage page =
        Vintasoft.Imaging.Pdf.PdfDocumentController.GetPageAssociatedWithImage(viewer.Image);
    if (page == null)
        throw new System.InvalidOperationException();

    // create and set PdfRemoveContentTool as current tool of image viewer
    Vintasoft.Imaging.Pdf.UI.PdfRemoveContentTool removeContentTool =
        new Vintasoft.Imaging.Pdf.UI.PdfRemoveContentTool();
    viewer.VisualTool = removeContentTool;

    // create the redaction mark
    Vintasoft.Imaging.Pdf.UI.RedactionMark mark =
        new Vintasoft.Imaging.Pdf.UI.RedactionMark(viewer.Image);
    // specify that redaction mark must remove all PDF content
    mark.MarkType = Vintasoft.Imaging.Pdf.PdfRedactionMarkType.RemoveAll;
    // calculate and specify the redaction mark rectangle
    System.Drawing.RectangleF rect = page.MediaBox;
    rect.Inflate(-rect.Width / 4, -rect.Height / 4);
    mark.SelectedRect = rect;

    // add the redaction mark to a list of redaction marks of visual tool
    removeContentTool.Add(mark);

    // create redaction mark appearance
    Vintasoft.Imaging.Pdf.Drawing.GraphicsFigures.TextBoxFigure textBox =
        new Vintasoft.Imaging.Pdf.Drawing.GraphicsFigures.TextBoxFigure(
            new Vintasoft.Imaging.Pdf.Drawing.PdfBrush(System.Drawing.Color.Red),
            "TOP SECRET",
            page.Document.FontManager.GetStandardFont(Vintasoft.Imaging.Pdf.Tree.Fonts.PdfStandardFontType.Helvetica),
            0);
    textBox.TextAlignment = Vintasoft.Imaging.Pdf.Drawing.PdfContentAlignment.Center;
    textBox.Brush = new Vintasoft.Imaging.Pdf.Drawing.PdfBrush(System.Drawing.Color.Black);
    textBox.AutoFontSize = true;
    removeContentTool.RedactionMarkAppearance = textBox;

    // apply redaction marks
    removeContentTool.ApplyRedactionMarks();
}