I had thought you were talking about what is really an extension of OCR (Optical Character Recognition) Where the computer is able to recognize shapes in image files. While the basics of simple two dimensional shapes is quite progressed, the last I heard people were still trying to develop anything more complex.
Surely, I am behind the times on this, since I know that facial recognition is a growth industry since September Eleventh.
A computer program which can recognize "ball" from a photo would seem to be easier than one which can recognize "face", but I suspect the reverse is true. A face has many clues which identify it, while a ball is nearly indistinguisable from a disk to a single camera.
But, like I said, I am certainly behind the times.
And, I keep reminding myself, the new version will allow many things that were impossible before. A decent Facial Recognition program made to provide HalCommands could be made...
...by someone who is not me, of course.....