Force CKFinder to use absolute url's instead of relative ones

I'm trying to force my CKFinder to return absolute url's instead of relative ones, but config section looks a bit confusing to me.

My config looks like:

public override void SetConfig()
    {                    
        var uploadDirectory = "~/images"

        BaseUrl = uploadDirectory;      
        BaseDir = "";  

This is returning paths to images as "/images/image.jpg", I need to display them as www.mysite.com/images/image.jpg