A visual code system wherein camera-equipped mobile phones (or similar devices, such as wireless PDAs) are used to identify and decode images that contain one or more "visual codes." By recognizing a code tag, the device can determine a bit pattern or an integer number encoded in the tag (the code value), the targeted object or image element, as well as additional parameters, such as the viewing angle of the camera. Code recognition is performed on the mobile device itself. When the mobile device is equipped with a wireless communication channel, it can be used to retrieve online content or to access information on the Internet based on the sensed code and its parameters. The retrieved content can then be presented on the mobile device.