PictureRelate compares pictures by similarity. Of course computers can't understand what's in a picture. Pattern recognition and image analysis has tried for many decades and has failed, so far. But there are some basic image properties that can be analyzed by a computer. PictureRelate uses a set of such features to classify images. These features were designed to mimic the human eye, i.e. they use what neurologists like to call "pop-out" features.