Allready did that:
image.set_ColorType(ImageMagick.ColorType::Bilevel);
image.set_ClassType(ImageMagick.ClassType::Pseudo);
image.ChangeColorSpace(ImageMagick.ColorSpace::RGB);
image.set_AntiAlias(false);
the image looks the same and has a bit depth of 8 if it's saved as a jpg and 32 if it's saved as png or bmp