Overlay image onto PDF using PDFSharp

Question

Can\'t seem to find much out there for this. I\'ve a PDF, onto which I\'d like to overlay an image of an electronic signature. Any suggestions on how to accomplish that usin

Answer 1

To roughly maintain the aspect ratio, I used @Kami's answer and "roughly" centered it. The assumption made is that the pdf width is 600 and pdf height is 800, we will make use of the middle 500 and 700 of the page only, leaving the 4 sides have at least 50 in length as margin.

    public static void GeneratePdf(string outputPath, string inputPath)
    {
        PdfSharp.Pdf.PdfDocument document = new PdfSharp.Pdf.PdfDocument();

        // Create an empty page or load existing
        PdfPage page = document.AddPage();

        // Get an XGraphics object for drawing
        XGraphics gfx = XGraphics.FromPdfPage(page);
        DrawImage(gfx, inputPath);

        // Save and start View
        document.Save(outputPath);
        Process.Start(outputPath);
    }

    public static void DrawImage(XGraphics gfx, string imagePath)
    {
        XImage image = XImage.FromFile(imagePath);
        var imageHeight = image.PixelHeight;
        var imageWidth = image.PixelWidth;
        int height;
        int width;
        int x;
        int y;

        width = 500;
        height = (int) Math.Ceiling((double) width * imageHeight / imageWidth);

        x = 50;
        y = (int) Math.Ceiling((800 - height) / 2.0);
        
        if(height > 700)
        {
            height = 700;
            width = (int) Math.Ceiling(imageWidth * (double) height / imageHeight);

            y = 50;
            x = (int) Math.Ceiling((600 - width) / 2.0);
        }
        
        gfx.DrawImage(image, x, y, width, height);
    }