Replace Images with Higher Quality Images

protected void convertToPdf()
{
    // Get the server IP and port
    String serverIP = textBoxServerIP.Text;
    uint serverPort = uint.Parse(textBoxServerPort.Text);

    // Create a HTML to PDF converter object
    HtmlToPdfConverter htmlToPdfConverter = null;
    if (radioButtonUseTcpService.Checked)
        htmlToPdfConverter = new HtmlToPdfConverter(serverIP, serverPort);
    else
        htmlToPdfConverter = new HtmlToPdfConverter(true, textBoxWebServiceUrl.Text);

    // Set optional service password
    if (textBoxServicePassword.Text.Length > 0)
        htmlToPdfConverter.ServicePassword = textBoxServicePassword.Text;

    // Set license key received after purchase to use the converter in licensed mode
    // Leave it not set to use the converter in demo mode
    htmlToPdfConverter.LicenseKey = "4W9+bn19bn5ue2B+bn1/YH98YHd3d3c=";

    // Set an adddional delay in seconds to wait for JavaScript or AJAX calls after page load completed
    // Set this property to 0 if you don't need to wait for such asynchcronous operations to finish
    htmlToPdfConverter.ConversionDelay = 2;

    // Select all images from HTML page
    htmlToPdfConverter.HtmlElementsMappingOptions.HtmlElementSelectors = new string[] { "img" };

    // Exclude the original images from rendering becuase they will be replaced by an image from local file system
    htmlToPdfConverter.HiddenHtmlElementsSelectors = new string[] { "img" };

    // Convert a HTML string with images to replace to a PDF document object
    Document pdfDocument = htmlToPdfConverter.ConvertUrlToPdfDocumentObject(urlTextBox.Text);

    // Replace the images selected in HTML using special attributes with images from local file system
    int mappingsCount = htmlToPdfConverter.HtmlElementsMappingOptions.HtmlElementsMappingResult.Count;
    for (int i = 0; i < mappingsCount; i++)
    {
        HtmlElementMapping imageElementInfo = htmlToPdfConverter.HtmlElementsMappingOptions.HtmlElementsMappingResult.GetByIndex(i);
        PdfPage imagePdfPage = pdfDocument.GetPage(imageElementInfo.PdfRectangles[0].PageIndex);
        RectangleFloat imageRectangle = imageElementInfo.PdfRectangles[0].Rectangle;

        ImageElement newImageElement = new ImageElement(imageRectangle.X, imageRectangle.Y, imageRectangle.Width, imageRectangle.Height,
                        Server.MapPath("~/DemoAppFiles/Input/Images/box.jpg"));
        newImageElement.EnlargeEnabled = true;
        imagePdfPage.AddElement(newImageElement);
    }

    // Save the PDF document in a memory buffer
    byte[] outPdfBuffer = pdfDocument.Save();
}