I don't understand what do you options 1-2 mean. In most cases, it would be a *.resx file included in your project. Just one advice: don't embed the image, use "Add existing file". This way, the image file will be added to both project (without copying it to output directory) and referenced in the resource file. In such settings, you will be able to edit the file separately, with any editor of your choice.
In WPF, you can use this option we well (will need to convert the image to the WPF bitmap, which is a disadvantage, please see this CodeProject article: Bitmap to BitmapSource
]), or you can use XAML resources, which is a way native to WPF. Please see: