WPF image resources

<Image Source="..MediaImage.png" />

<Image Source="/WPFApplication;component/Images/Start.png" />

doGetImageSourceFromResource ("[YourAssemblyNameHere]", "[YourResourceNameHere]");

static internal ImageSource doGetImageSourceFromResource(string psAssemblyName, string psResourceName)
{
    Uri oUri = new Uri("pack://application:,,,/" +psAssemblyName +";component/" +psResourceName, UriKind.RelativeOrAbsolute);
    return BitmapFrame.Create(oUri);
}

<BitmapImage x:Key="MyImageSource" UriSource="Resources/Image.png" />