''' <summary>
''' Draws the selection region for text region line on specified image.
''' </summary>
''' <param name="image">An image that contains text and where selection region must be drawn.</param>
''' <returns>
''' A clone of image that contains text and with drawn selection region.
''' </returns>
Public Shared Function DrawTextRegionSelection(image As Vintasoft.Imaging.VintasoftImage) As Vintasoft.Imaging.VintasoftImage
    ' create result image
    Dim result As Vintasoft.Imaging.VintasoftImage = DirectCast(image.Clone(), Vintasoft.Imaging.VintasoftImage)

    ' get the text region lines
    Dim textRegionLines As Vintasoft.Imaging.Text.TextRegionLine() = image.Metadata.TextRegion.Lines

    ' if image has text regions
    If textRegionLines.Length > 0 Then
        ' create the drawing engine
        Using darawingEngine As Vintasoft.Imaging.Drawing.DrawingEngine = result.CreateDrawingEngine()
            ' create transform from text to an image space
            Dim textToImageTransform As Vintasoft.Imaging.AffineMatrix = image.Metadata.TextRegion.GetTransformFromTextToImageSpace(image.Resolution)

            ' create brushes
            Using lineBrush As Vintasoft.Imaging.Drawing.IDrawingBrush = darawingEngine.DrawingFactory.CreateSolidBrush(New Vintasoft.Imaging.ImageColors.Argb32Color(128, 0, 128, 0))
                Using symbolPen As Vintasoft.Imaging.Drawing.IDrawingPen = darawingEngine.DrawingFactory.CreatePen(New Vintasoft.Imaging.ImageColors.Argb32Color(255, 0, 0, 255), 1)
                    For Each textRegionLine As Vintasoft.Imaging.Text.TextRegionLine In textRegionLines
                        ' get points of text region line
                        Dim linePoints As System.Drawing.PointF() = textRegionLine.SelectionRegion.ToPolygon()

                        ' transform points
                        Vintasoft.Imaging.PointFAffineTransform.TransformPoints(textToImageTransform, linePoints)

                        ' fill line polygon
                        darawingEngine.FillPolygon(lineBrush, linePoints)

                        ' for each symbol in text region line
                        For Each textRegionSymbol As Vintasoft.Imaging.Text.TextRegionSymbol In textRegionLine.Symbols
                            ' get points of text symbol
                            Dim symbolPoints As System.Drawing.PointF() = textRegionSymbol.SelectionRegion.ToPolygon()

                            ' transform points
                            Vintasoft.Imaging.PointFAffineTransform.TransformPoints(textToImageTransform, symbolPoints)

                            ' fill symbol polygon
                            darawingEngine.DrawPolygon(symbolPen, symbolPoints)
                        Next
                    Next
                End Using
            End Using
        End Using
    End If

    Return result
End Function

/// <summary>
/// Draws the selection region for text region line on specified image.
/// </summary>
/// <param name="image">An image that contains text and where selection region must be drawn.</param>
/// <returns>
/// A clone of image that contains text and with drawn selection region.
/// </returns>
public static Vintasoft.Imaging.VintasoftImage DrawTextRegionSelection(Vintasoft.Imaging.VintasoftImage image)
{
    // create result image
    Vintasoft.Imaging.VintasoftImage result = (Vintasoft.Imaging.VintasoftImage)image.Clone();

    // get the text region lines
    Vintasoft.Imaging.Text.TextRegionLine[] textRegionLines = image.Metadata.TextRegion.Lines;

    // if image has text regions
    if (textRegionLines.Length > 0)
    {
        // create the drawing engine
        using (Vintasoft.Imaging.Drawing.DrawingEngine darawingEngine = result.CreateDrawingEngine())
        {
            // create transform from text to an image space
            Vintasoft.Imaging.AffineMatrix textToImageTransform = image.Metadata.TextRegion.GetTransformFromTextToImageSpace(image.Resolution);

            // create brushes
            using (Vintasoft.Imaging.Drawing.IDrawingBrush lineBrush = darawingEngine.DrawingFactory.CreateSolidBrush(new Vintasoft.Imaging.ImageColors.Argb32Color(128, 0, 128, 0)))
            {
                using (Vintasoft.Imaging.Drawing.IDrawingPen symbolPen = darawingEngine.DrawingFactory.CreatePen(new Vintasoft.Imaging.ImageColors.Argb32Color(255, 0, 0, 255), 1))
                {
                    foreach (Vintasoft.Imaging.Text.TextRegionLine textRegionLine in textRegionLines)
                    {
                        // get points of text region line
                        System.Drawing.PointF[] linePoints = textRegionLine.SelectionRegion.ToPolygon();

                        // transform points
                        Vintasoft.Imaging.PointFAffineTransform.TransformPoints(textToImageTransform, linePoints);

                        // fill line polygon
                        darawingEngine.FillPolygon(lineBrush, linePoints);

                        // for each symbol in text region line
                        foreach (Vintasoft.Imaging.Text.TextRegionSymbol textRegionSymbol in textRegionLine.Symbols)
                        {
                            // get points of text symbol
                            System.Drawing.PointF[] symbolPoints = textRegionSymbol.SelectionRegion.ToPolygon();

                            // transform points
                            Vintasoft.Imaging.PointFAffineTransform.TransformPoints(textToImageTransform, symbolPoints);

                            // fill symbol polygon
                            darawingEngine.DrawPolygon(symbolPen, symbolPoints);
                        }
                    }
                }
            }
        }
    }

    return result;
}