I am trying to use a photograph of a city panorama as an image target. When upload it to My Trackables page and try to convert it into an image target, I only get one, sometimes two stars of quality and the system doesn't let me use the photograph. There are, however, quite a few features that the tracking algorithm should lock onto, I think. I saw others using less sophisticated images as image targets. For example, on this site http://gavinmhackeling.com/?p=10, they use gallery images from afar and it works. On other examples, I saw a photograph of a single-colored shoe that worked well. How do people get these images to work as image targets? How do I make it get at least 3 stars so that I can use it? The Metaio SDK works quite well with my photographs, so it seems have better tracking capabilities, but it's extremely expensive, so I'd prefer to use Vuforia.