Mobile device which automatically determines operating mode

A mobile device such as a cell phone is used to remotely control an electronic appliance such as a television or personal computer. In a setup phase, the mobile device captures an image of the electronic appliance and identifies and stores scale-invariant features of the image. A user interface configuration such as a virtual keypad configuration, and a communication protocol, can be associated with the stored data. Subsequently, in an implementation phase, another image of the electronic appliance is captured and compared to the stored features in a library to identify a match. In response, the associated user interface configuration and communication protocol are implemented to control the electronic appliance. In a polling and reply process, the mobile device captures a picture of a display of the electronic device and compares it to image data which is transmitted by the electronic appliance.