public enum OutputImageFormat : System.Enum, System.IComparable, System.IConvertible, System.IFormattable, System.ISpanFormattable  

//Note: Run within QueuedTask.Run
//Create a point symbol
var pointSymbol = SymbolFactory.Instance.ConstructPointSymbol(
  ColorFactory.Instance.RedRGB, 24, SimpleMarkerStyle.RoundedSquare);

//Generate image returns a stream
//OutputImageFormat specified the format for the image - in this case
//we want SVG (an xml-based format)
//
//output fmt: SVG, scale factor x2, centerAnchorPoint = true
//dpi = 300, wd x ht: 100x100px, background: white
var mem_strm = SymbolFactory.Instance.GenerateImage(
  pointSymbol, OutputImageFormat.SVG, 2.0, true, 300, 100, 100,
  ColorFactory.Instance.WhiteRGB);

//Set the memory stream position to the beginning
mem_strm.Seek(0, SeekOrigin.Begin);

//File path and name for saving the SVG file
var fileName = "RoundedSquareSymbol.svg";
string path_svg = Path.Combine(Path.GetTempPath() + fileName);

//Write the memory stream to the file
System.IO.File.WriteAllBytes(path_svg, mem_strm.ToArray());

//////////////////////////////////////////////
//Note: to convert SVG to image format, use a 3rd party
//e.g. Aspose.SVG for .NET, for example convert SVG to PNG
//using (var svg_doc = new Aspose.Svg.SVGDocument(path_svg))
//{
//  string path_png = Path.Combine(Path.GetTempPath() + "RoundedSquareSymbol.png");
//  using (var img_png = new Aspose.Svg.Rendering.Image.ImageDevice(
//    new ImageRenderingOptions(ImageFormat.Png), path_png))
//  {
//    svg_doc.RenderTo(img_png);
//  }
//  //also: https://docs.aspose.com/imaging/net/convert-svg-to-png/
//}

//Note: Run within QueuedTask.Run
//Create a point symbol
var pointSymbol = SymbolFactory.Instance.ConstructPointSymbol(
  ColorFactory.Instance.RedRGB, 24, SimpleMarkerStyle.RoundedSquare);

//Generate image returns a stream
//OutputImageFormat specified the format for the image - in this case
//we want PNG
//
//output fmt: PNG, scale factor x2, centerAnchorPoint = true
//dpi = 300, wd x ht: 100x100px, background: white
var mem_strm = SymbolFactory.Instance.GenerateImage(
  pointSymbol, OutputImageFormat.PNG, 2.0, true, 300, 100, 100,
  ColorFactory.Instance.WhiteRGB);

//Set the memory stream position to the beginning
mem_strm.Seek(0, SeekOrigin.Begin);

//Write the stream to a bit map
var bitmapImage = new System.Windows.Media.Imaging.BitmapImage();

bitmapImage.BeginInit();
bitmapImage.StreamSource = mem_strm;
bitmapImage.CacheOption = System.Windows.Media.Imaging.BitmapCacheOption.OnLoad;
bitmapImage.EndInit();
bitmapImage.Freeze();

//Write the bit map out to a file
//File path and name for saving the PNG file
var fileName = "RoundedSquareSymbol.png";
string path_png = Path.Combine(Path.GetTempPath() + fileName);

BitmapEncoder encoder = new PngBitmapEncoder();
encoder.Frames.Add(BitmapFrame.Create(bitmapImage));

using (var fileStream = new System.IO.FileStream(
  path_png, System.IO.FileMode.Create))
{
  encoder.Save(fileStream);
}