/// <summary>
/// Returns the scaled image region.
/// </summary>
/// <param name="image">The source image.</param>
/// <param name="rect">The image region on source image, which should be rendered.</param>
/// <param name="scale">The scale factor, which should be applied to the image region.</param>
/// <returns>The scaled image region.</returns>
public static Vintasoft.Imaging.VintasoftImage RenderScaledImageRegion(
    Vintasoft.Imaging.VintasoftImage image,
    System.Drawing.Rectangle rect,
    float scale)
{
    // create the image renderer
    using (Vintasoft.Imaging.ImageRendering.ImageRenderer renderer = 
        new Vintasoft.Imaging.ImageRendering.ImageRenderer(image))
    {
        // create the rendering task
        Vintasoft.Imaging.ImageRendering.ImageRenderingTask task = 
            Vintasoft.Imaging.ImageRendering.ImageRenderingTask.CreateImageRegion(rect, scale);
        // execute the rendering
        return renderer.ExecuteRendering(task);
    }
}

''' <summary>
''' Returns the scaled image region.
''' </summary>
''' <param name="image">The source image.</param>
''' <param name="rect">The image region on source image, which should be rendered.</param>
''' <param name="scale">The scale factor, which should be applied to the image region.</param>
''' <returns>The scaled image region.</returns>
Public Shared Function RenderScaledImageRegion(image As Vintasoft.Imaging.VintasoftImage, rect As System.Drawing.Rectangle, scale As Single) As Vintasoft.Imaging.VintasoftImage
    ' create the image renderer
    Using renderer As New Vintasoft.Imaging.ImageRendering.ImageRenderer(image)
        ' create the rendering task
        Dim task As Vintasoft.Imaging.ImageRendering.ImageRenderingTask = Vintasoft.Imaging.ImageRendering.ImageRenderingTask.CreateImageRegion(rect, scale)
        ' execute the rendering
        Return renderer.ExecuteRendering(task)
    End Using
End Function

/// <summary>
/// Returns a 4 times downscaled image of left-top rectangle of JPEG2000 image.
/// </summary>
public static Vintasoft.Imaging.VintasoftImage GetJpeg2000RectangleDownscaled4(string filename)
{
    using (System.IO.Stream stream =
        new System.IO.FileStream(filename, System.IO.FileMode.Open, System.IO.FileAccess.Read))
    {
        using (Vintasoft.Imaging.Codecs.Decoders.Jpeg2000Decoder decoder =
            new Vintasoft.Imaging.Codecs.Decoders.Jpeg2000Decoder(stream))
        {
            // check available scales
            int[] scales = decoder.GetImageRectScales(0, decoder.GetDefaultDecodingSettings(0));
            for (int i = 0; i < scales.Length; i++)
            {
                if (scales[i] == 4)
                {
                    // get top-left rectangle of raster grid with scale 4
                    return decoder.GetImageRect(0, 0, 4, null, null, null);
                }
            }

            throw new System.Exception("Scale 4 is not available for specified JPEG2000 file.");
        }
    }
}

''' <summary>
''' Returns a 4 times downscaled image of left-top rectangle of JPEG2000 image.
''' </summary>
Public Shared Function GetJpeg2000RectangleDownscaled4(filename As String) As Vintasoft.Imaging.VintasoftImage
    Using stream As System.IO.Stream = New System.IO.FileStream(filename, System.IO.FileMode.Open, System.IO.FileAccess.Read)
        Using decoder As New Vintasoft.Imaging.Codecs.Decoders.Jpeg2000Decoder(stream)
            ' check available scales
            Dim scales As Integer() = decoder.GetImageRectScales(0, decoder.GetDefaultDecodingSettings(0))
            For i As Integer = 0 To scales.Length - 1
                If scales(i) = 4 Then
                    ' get top-left rectangle of raster grid with scale 4
                    Return decoder.GetImageRect(0, 0, 4, Nothing, Nothing, Nothing)
                End If
            Next

            Throw New System.Exception("Scale 4 is not available for specified JPEG2000 file.")
        End Using
    End Using
End Function

/// <summary>
/// Returns an enlarged image of the central region of PDF page.
/// </summary>
public static Vintasoft.Imaging.VintasoftImage GetEnlargedImageOfPdfPageRegion(string filename, int pageIndex)
{
    using (System.IO.Stream stream =
        new System.IO.FileStream(filename, System.IO.FileMode.Open, System.IO.FileAccess.Read))
    {
        using (Vintasoft.Imaging.Codecs.Decoders.PdfDecoder decoder =
            new Vintasoft.Imaging.Codecs.Decoders.PdfDecoder(stream))
        {
            // settings for page rendering
            Vintasoft.Imaging.Codecs.Decoders.RenderingSettings renderingSettings =
                Vintasoft.Imaging.Codecs.Decoders.RenderingSettings.Empty;
            // get page info
            Vintasoft.Imaging.Codecs.Decoders.ImageInfo pageInfo = decoder.GetImageInfo(pageIndex, renderingSettings, null);

            // determine region on page
            float x = 3f * pageInfo.Width / 8f;
            float y = 3f * pageInfo.Height / 8f;
            float width = pageInfo.Width / 4f;
            float height = pageInfo.Height / 4f;
            System.Drawing.RectangleF rect = new System.Drawing.RectangleF(x, y, width, height);

            // get the central region with size of 1/4 page and scale 4
            return decoder.GetImage(pageIndex, rect, 4f, null, renderingSettings, null, null);
        }
    }
}

''' <summary>
''' Returns an enlarged image of the central region of PDF page.
''' </summary>
Public Shared Function GetEnlargedImageOfPdfPageRegion(filename As String, pageIndex As Integer) As Vintasoft.Imaging.VintasoftImage
    Using stream As System.IO.Stream = New System.IO.FileStream(filename, System.IO.FileMode.Open, System.IO.FileAccess.Read)
        Using decoder As New Vintasoft.Imaging.Codecs.Decoders.PdfDecoder(stream)
            ' settings for page rendering
            Dim renderingSettings As Vintasoft.Imaging.Codecs.Decoders.RenderingSettings = Vintasoft.Imaging.Codecs.Decoders.RenderingSettings.Empty
            ' get page info
            Dim pageInfo As Vintasoft.Imaging.Codecs.Decoders.ImageInfo = decoder.GetImageInfo(pageIndex, renderingSettings, Nothing)

            ' determine region on page
            Dim x As Single = 3F * pageInfo.Width / 8F
            Dim y As Single = 3F * pageInfo.Height / 8F
            Dim width As Single = pageInfo.Width / 4F
            Dim height As Single = pageInfo.Height / 4F
            Dim rect As New System.Drawing.RectangleF(x, y, width, height)

            ' get the central region with size of 1/4 page and scale 4
            Return decoder.GetImage(pageIndex, rect, 4F, Nothing, renderingSettings, Nothing, _
                Nothing)
        End Using
    End Using
End Function