A method for transmitting data to a camera without requiring in the camera a conventional wireless transmission capability includes (a) in the camera's field of view, providing an object which forms an image on which the data is encoded, (b) capturing an image of the object using optics of the camera, and (c) recovering the data from the image of the object. The data is encoded by an optically detectable quantity (e.g., light intensity or color) or a pattern in one or more portions of the object. The data can be earned by the distribution of the optically detectable quantity within the image or its derivative. The field of view of the camera may be divided into multiple sub-areas to allow providing multiple data-bearing images. A sequence of such images may be used to increase the amount of data that can be transmitted in this manner.