| 摘要 |
<p>A control device divides one frame into a plurality of sub-frames, distributes image signals of an embedded image to be provided to a particular user, into a plurality of sub-frames so that the total of signal levels in one frame is zero, and superposes the image signals on an image signal of an basic image to be provided to unspecified users when displaying the frame on a display device. A reception device captures an image displayed on the display device for each cycle identical to the cycle of the sub-frames and obtains a difference between two image signals obtained at each cycle identical to the cycle of the sub-frames, so as to acquire and display an image signal of the embedded image.</p> |
