public enum JPEGColorMode : System.Enum, System.IComparable, System.IConvertible, System.IFormattable  

//Export a map frame to JPG.

//Create JPEG format with appropriate settings
//BMP, EMF, EPS, GIF, PDF, PNG, SVG, TGA, and TFF formats are also available for export
//at 2.x - JPEGFormat JPG = new JPEGFormat()
//{
//  HasWorldFile = true,
//  Resolution = 300,
//  OutputFileName = filePath,
//  JPEGColorMode = JPEGColorMode.TwentyFourBitTrueColor,
//  Height = 800,
//  Width = 1200
//};
JPEGFormat JPG = new JPEGFormat()
{
  HasWorldFile = true,
  Resolution = 300,
  OutputFileName = filePath,
  ColorMode = JPEGColorMode.TwentyFourBitTrueColor,
  Height = 800,
  Width = 1200
};

//Reference the map frame
MapFrame mf = layout.FindElement("MyMapFrame") as MapFrame;

//Export on the worker thread
await QueuedTask.Run(() =>
{
  //Check to see if the path is valid and export
  if (JPG.ValidateOutputFilePath())
  {
    mf.Export(JPG);  //Export the map frame to JPG
  }
});