public bool Convert(FilterRequest req)
        {
            string source = req.Current.LocalPath;

            System.Uri dest_uri = req.TempUri(System.IO.Path.GetExtension(source));
            string     dest     = dest_uri.LocalPath;

            using (ImageFile img = ImageFile.Create(source)) {
                bool changed = false;

                if (img.Orientation != PixbufOrientation.TopLeft && img is JpegFile)
                {
                    JpegFile jimg = img as JpegFile;

                    if (img.Orientation == PixbufOrientation.RightTop)
                    {
                        JpegUtils.Transform(source,
                                            dest,
                                            JpegUtils.TransformType.Rotate90);
                        changed = true;
                    }
                    else if (img.Orientation == PixbufOrientation.LeftBottom)
                    {
                        JpegUtils.Transform(source,
                                            dest,
                                            JpegUtils.TransformType.Rotate270);
                        changed = true;
                    }
                    else if (img.Orientation == PixbufOrientation.BottomRight)
                    {
                        JpegUtils.Transform(source,
                                            dest,
                                            JpegUtils.TransformType.Rotate180);
                        changed = true;
                    }

                    int width, height;

                    jimg = ImageFile.Create(dest) as JpegFile;

                    PixbufUtils.GetSize(dest, out width, out height);

                    jimg.SetOrientation(PixbufOrientation.TopLeft);
                    jimg.SetDimensions(width, height);

                    Gdk.Pixbuf pixbuf = new Gdk.Pixbuf(dest, 160, 120, true);
                    jimg.SetThumbnail(pixbuf);
                    pixbuf.Dispose();

                    jimg.SaveMetaData(dest);
                    jimg.Dispose();
                }

                if (changed)
                {
                    req.Current = dest_uri;
                }

                return(changed);
            }
        }