The ConvertToEmfPlus method described in the stackoverflow post did not work. And writing my own enumeration sounds like too much work. I have a simpler work-around for you. You could just blur the image a bit:
MagickReadSettings settings = new MagickReadSettings() { Density = new MagickGeometry(1200) }; using (MagickImage image = new MagickImage(@"D:\images\emf\8060.emf", settings)) { // If you don't do this the alpha channel will also be blurred. image.Alpha(AlphaOption.Deactivate); image.Blur(1, Quantum.Max); image.Write(@"D:\images\emf\test.png"); }