Saving Bitmap Images in WPF via C#

I display images in my WPF app using BitmapImage. However, I would like an easy way to save these (as JPG) to a different location (ideally into a Stream or object that can be passed around).

Is it possible using BitmapImage or do I have to 开发者_如何学编程use other means? If so what other means are there for either loading an Image and saving as JPG or converting a BitmapImage into this element to then save off?

Thanks

Something like:

public byte[] GetJPGFromImageControl(BitmapImage imageC)
{
    MemoryStream memStream = new MemoryStream();
    JpegBitmapEncoder encoder = new JpegBitmapEncoder();
    encoder.Frames.Add(BitmapFrame.Create(imageC));
    encoder.Save(memStream);
    return memStream.GetBuffer();
}

(from: WPF Image to byte[])