Fix bug transparency watermark for PDF

[Antonio-Russo]

There is a small but annoying bug that does not allow you to manage transparencies. Thanks

[shaynethiessen]

There is a problem with your fix. The rasterizer will no longer respect the pdf's page rotation.

            GhostscriptVersionInfo gvi = new GhostscriptVersionInfo(Loader.GetGhostScriptDLL());
            using (GhostscriptRasterizer rasterizer = new GhostscriptRasterizer())
            {
                rasterizer.Open(filePath, gvi, false);
                img = rasterizer.GetPage(96, 96, pageNumber);
            }

When converting a pdf page to an image (as shown above), it no longer keeps the rotation but instead automatically rotates it to portrait.

[shaynethiessen]

I found a fix for that. Removing the following line from viewer\FormatHandlers\GhostscriptViewerPsFormatHandler.cs fixes it.

this.Interpreter.Run(string.Format("/Orientation {0}\n", (int)this.CurrentPageOrientation));