Imagery, video, maps or signs are embedded with plural-bit data in the form of digital watermarking. In one embodiment, a method includes obtaining a media signal representing an image or video; introducing digital watermarking into the media signal, the digital watermarking slightly altering samples of the media signal; and the digital watermarking changing across the media signal so as to convey first information related to at least a first area depicted in the image or within data representing a first portion of the video in the media signal and second, different information related to at least a second area depicted in the image or within data representing a second portion of the video in the media signal. Other embodiments are provided as well.